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The Rokinon 135mm F/2 was Built for Astrophotography

|Camera Lenses|8 Comments

In this post, I’ll explain why I think the Rokinon 135mm F/2 is the perfect addition to an arsenal of astrophotography lenses. 

Deep sky astrophotography is often associated with a camera and telescope, but the truth is there are a lot of great camera lenses for astrophotography out there. In the past, I’ve covered a number of different lenses, from the Rokinon 14mm F/2.8 to the Canon EF 300mm F/4L.

As you know, camera lenses come in varying focal lengths, apertures, and optical quality. Astrophotography is one of the ultimate tests of lens quality, as long exposure photography of deep-sky objects in space can highlight issues that are hidden during daytime photography.

In this post, I’ll share my results using an affordable prime telephoto lens for astrophotography, the Rokinon 135mm F/2.0 ED UMC. The version I have has the mount for Canon EOS camera bodies, but there are several different lens mounts available on Amazon.

Rokinon 135 F2 ED UMC

My Canon EOS 60Da with the Rokinon 135mm F/2.0 mounted to a Fornax Mounts LighTrack II.

This lens is available for several camera mounts, including Nikon, Sony, Pentax, Samsung, and Fuji. I purchased this lens for the purposes of wide-field deep sky astrophotography from my light polluted backyard (shown below), and when traveling to a dark sky site.

Taking images at this focal length from the city will swell issues with gradients, especially when shooting towards the “light dome”. For this reason, a combination of a good light pollution filter, and the use of flat calibration frames are recommended. Before I go any further, I’d like to share a photo from Gabriel Millou of the Andromeda Galaxy using a Canon 1300D.

Samyang 135mm F/2

The Andromeda Galaxy using the Rokinon 135mm F/2.0 ED UMC lens. 

To see even more example photos using the Rokinon 135mm lens (or Samyang branded version), go ahead a perform a search on Astrobin or Flickr, with the appropriate filter. I think you’ll find that this lens is behind some of the most amazing wide-field astrophotography images online!

The Rokinon 135mm F/2 ED UMC

The full name of this lens is the Rokinon 135mm F/2 ED UMC, with “ED” standing for extra-low dispersion, and UMC referring to the “ultra multi-coated” optics. This is a fully manual lens, meaning that it does not have autofocus, and you must manually select the f-stop using the aperture ring at the base of the lens.

Manually focusing a lens for astrophotography is nothing new, but the manual aperture ring adjustments may feel a little strange at first. 

Rokinon lenses are made in Korea, and so is the Samyang variation. The full extent of the relationship between Rokinon and Samyang is unknown to me, but the packaging on my lens says “Technology by Samyang Optics”. I typically shoot with Canon lenses, but the potential for low light photography (whether that’s astrophotography or the ability to film at dusk) caught my interest.

Rokinon 135mm F/2 lens specifications

The diameter of the lens is 77mm, with a non-rotating filter mount on the objective lens. The lens hood is removable (and reversible), which makes packing the Rokinon 135mm away into the included lens pouch possible. The presentation and hands-on look and feel of the 135mm F/2 lens is impressive considering the reasonable price of this lens. 

The aperture range of this lens is F/2 to F/22, with 9 diaphragm blades (aperture blades) that work in harmony to set your f-stop. The aperture ring is marked with each f-stop, and you need to manually click through F/2 – F/22 and watch the blades do their work. It’s actually kind of neat to watch!

I ordered this lens on Amazon, utilizing my Amazon Prime membership. The lens arrived next day, less than 24 hours after I hit the order button. The lens came in a handsome box, with core specifications and a lens construction diagram printed on the side. The Rokinon 135mm F/2.0 includes a lens hood, lens pouch, front and rear lens caps, and a 1-year Rokinon manufacturer warranty.

First Impressions

Overall, the lens feels very solid and well constructed. The finish and texture of the Rokinon 135mm F/2 is a step up from the 14mm F/2.8 I ordered a few years ago. 

The spec sheet for the Rokinon 135mm F/2 boasts a number of qualities, with the ones listed below being the most important when it comes to night photography and astro. Based on my handful of experiences with this lens in the backyard, I have found these traits to hold true.

  • Low-Light Performance
  • Low Chromatic Aberration
  • Low Flare and Ghosting

The image below highlights the creative freedom this lens provides. To fit the Heart and Soul Nebulae in a single frame requires an extremely wide field of view (compared to the magnification of most telescopes). The 135mm focal length is absolutely perfect for the Heart and Soul Nebulae if you’re using a crop sensor DSLR camera.

The image shown below covers 4.96 x 5.98 degrees in the constellation Cassiopeia. The images were collected using a Canon EOS Rebel T3i camera riding on a Fornax Mounts LighTrack II

heart and soul nebula

The Heart and Soul Nebulae captured using a DSLR and the Rokinon 135mm lens. 

The Rokinon website lists this lens as being useful for portraiture photography, and most telephoto applications. The shallow depth of field present at its maximum aperture does indeed create a pleasing bokeh. 

The lens hood is not petal-shaped, which is great news for those using this lens for astrophotography. The flat lens hood design allows you to easily take flat frames with the Rokinon 135mm using the white t-shirt method or using a flat panel. 

I should mention that I have only tested this full-frame lens using my astrophotography DSLR’s, all of which are crop-sensor camera bodies. This creates an effective focal length of roughly 200mm, a useful magnification for a wide variety of astro-imaging scenarios. 

I am no stranger to the full manual control of this lens, for both aperture and focus. The Rokinon 14mm F/2.8 was the first lens I had ever used like this, and these aspects do not hinder the astrophotography experience whatsoever. 

A Full Frame, Prime Lens

The Rokinon 135mm F2.0 is considered to be a full-frame lens because it can accommodate a full-frame image sensor with its 18.8-degree angle of view. In this review, however, I am using the lens on a crop sensor (APS-C) Canon EOS 60Da, which puts the field of view at 12.4 degrees.

“Prime” means that this lens is fixed at 135mm, it is not a zoom lens that allows for focal length adjustments. Prime lenses are typically lighter as they do not need the additional glass and mechanics required to zoom at varying magnifications. 

Generally, prime lenses have a reputation for being slightly sharper, and I have found that to be true whether I am shooting a nebula or a Scarlet Tanager. 

The optical design includes one extra-low dispersion (ED) lens element to control chromatic aberration, and “ultra multi-coatings” (UMC) to both improve light transmission and reduce flare. 

lens focal length

The flat lens hood is great for taking flat frames after a night of astrophotography.

Low Light Capabilities at F/2.0

The F/2.0 maximum aperture of the Rokinon 135mm lens offers a chance to collect a serious amount of signal in a single shot. This allows for less aggressive camera settings for night photography such as using a lower ISO setting and even a shorter exposure. 

Of course, when it comes to astrophotography, this can create some challenges as well. Focusing a “wide open” F/2 lens is demanding of the optics, especially on a field of stars in the night sky. 

One way to combat potential soft images and chasing perfect focus all night is to stop the lens down to F/2.8 or even F/4. Your images have a chance at remaining sharper once critical focus has been achieved, but now you have lost the extra light-gathering power you wanted. It’s a trade-off, and one that seems to surface time and time again in this hobby.

Although typically unused in astrophotography, I did get a chance to see the beautiful bokeh this lens creates when shooting at F/2. The aesthetic quality of the blur in the out-of-focus parts of the image are buttery smooth and soft. 

lens for astrophotography

What I Really Like

Although this lens feels solid, it is rather light when compared to a telescope. When coupled with my Canon DSLR camera, the entire system weighs just over 3 pounds. That means that doesn’t require a robust equatorial telescope mount as a larger, heavier telephoto lens would. 

A camera tracker (or “star tracker”) is necessary for long exposure deep-sky astrophotography, but a compact model such as the iOptron SkyTracker or Sky-Watcher Star Adventurer will do just fine. 

This lens has a long focus adjustment ring, with great tension. The focuser adjustment rotates roughly 270 degrees, meaning fine-tuning on a bright star is more precise. You’ll never have to worry about losing your position just by touching the lens, but you can always tape the position down to be sure. 

The Rokinon 135mm F/2.0 ED UMC is one of the most affordable and practical lenses for astrophotography on the market. Sure, the “Nifty 50” is an incredible value (and a LOT cheaper), but the 135mm puts you within range of some of the best astrophotography targets in the night sky. 

I’ve spent a handful of nights testing this lens in my Bortle Scale Class 6/7 backyard, and my results live up to the hype it gets in terms of astrophotography performance.

Comparable Lenses (Chart)

Lens Comparison

BrandFocal LengthMaximum AperturePrice
Canon135mmF/2.0$999 (B & H)
Nikon135mmF/2.0$1,391 (B & H)
Sony135mmF/1.8$1,898 (B & H)
Rokinon135mmF/2.0$499 (Amazon)

Lens Comparison

Over the years, I’ve shot deep-sky targets at varying focal lengths from 50mm to over 1000mm. The closest I’ve been to the 135mm range is 105mm on my Canon 24-105 zoom.

Not only does the Rokinon 135 add additional reach, but I can also now shoot at F/2, instead of F/4 on the Canon. Below, are a few examples of astrophotography images I’ve taken with lenses of varying focal lengths. 

As you can see, the magnification of the lens used will dictate the type of projects you shoot.

lens comparison

  1. The Great Rift of the Milky Way – Rokinon 14mm F/2.8 
  2. Mars meets Pleiades – Canon EF 24-104mm F/4L
  3. Wide-field Sadr Region – Rokinon 135mm F/2.0
  4. The Carina Nebula – William Optics RedCat 51

So what’s so great about shooting at 135mm anyway?

The RedCat is deeper at 250mm, and after that, you’re into 300-400mm territory which pulls galaxies and nebulae even closer. Why take a step back from 250 to sit between the RedCat and the 24-105?

It’s all about framing.

Image Scale at 135mm

From the moment I reviewed the first sub-exposure on the display screen of my camera, I feel in love with the mid-range magnification of a 135mm lens. My first shot was a section of the constellation Sagittarius that included the Lagoon Nebula, and Trifid Nebula.

If you want to preview the image field you can expect with a particular camera sensor and lens combination, Stellarium features a useful tool. The Image Sensor Frame tool lets you enter in the size of your camera sensor, and focal length of your lens (or telescope) to display a frame over the star map.

This is a very practical way to plan your next astrophotography project, and especially handy when using a wide field lens like the Rokinon 135mm F/2. 

astrophotography scale

You can use Stellarium to preview the image scale with the 135mm lens and your DSLR. 

At 135mm, you can get really creative about the object or objects you shoot and where you position them within the frame.

And because you can shoot between F/2 and F/4, plenty of light reaches the sensor in a relatively short exposure. This has several advantages from less demanding tracking accuracy, to being able to use a lower ISO setting.

The Downsides of this Lens

Now, I have to admit that up to this point, it sounds a little too good to be true. The downsides of this configuration are that shooting wide open can make focusing difficult.

The focuser adjustment ring on the Rokinon 135mm F/2 is excellent, but fine-tuning your critical focus on a bright star at F/2 will take some trial and error to get right. You may need to refocus your subject as the temperature changes throughout the night. 

You may need to stop down to control star bloat, and that’s exactly what I’ve done with this 135. I’ve set the f-stop to F/2.8, to sharpen up the stars a bit. In fact, in my test shots, I noticed that the red channel was a little softer than green and blue. To remedy this, I reduced the star size in post, and I started shooting at F/4 to really tighten things up.

Also, as creative as the wide field 135mm focal length is, it’s not practical for smaller DSO’s and most galaxies. Stick to Andromeda, and skip the Whirlpool.

Andromeda Galaxy

The Andromeda Galaxy (Cropped). Canon EOS 60Da with the Rokinon 135mm F/2 lens.

I have heard others mention that this lens has a “plasticky” build quality, but I believe this aspect has been improved. The model I use feels solid and the barrel is constructed with metal.

The lens is not weather-sealed, so you definitely don’t want to leave your camera and lens (and your tracking mount!) in the rain. There’s no image stabilization on the Rokinon 135mm F/2 either, but that’s a non-issue for amateur astrophotographers. 

135mm lens

The North America Nebula captured using the 135mm lens with a clip-in Ha filter.

Recommend Astrophotography Targets for this Lens

I’ve captured a lot of deep-sky astrophotography targets from the northern hemisphere, but I’m usually in too deep to capture an entire region of space at once. Here is a short list of great astrophotography targets to shoot at 135mm with this lens:

  • Orion’s Belt (Including the Horsehead Nebula, Orion Nebula, and M78
  • The Witch Head Nebula including Rigel in Orion (Careful with star reflection!)
  • The Rosette Nebula and Surrounding Nebulosity
  • Cygnus, including the North America Nebula and Pelican Nebula
  • The Sadr Region in Cygnus including the Crescent Nebula
  • The Blue Horsehead Nebula in Scorpius
  • The Rho Ophiuchi Cloud Complex in the constellation Ophiuchus

Below, is an incredible example of the types of projects possible with the Rokinon 135mm F/2.0 lens. The following image was captured by Eric Cauble using the Samyang branded version of this lens. 

astrophotography example image

The Sadr Region in Cygnus, including the Crescent Nebula by Eric Cauble. 

Since Eric was so generous to share his images with me, I had to include his photo of the Rho Ophiuchi cloud complex as well. This photo was captured with the Samyang 135mm F/2 lens using a UV/IR cut filter and a QHY168C dedicated astronomy camera.

Rho Ophiuchi Cloud Complex

The Rho Ophiuchi Cloud Complex by Eric Cauble using the Samyang 135mm F/2 lens. See the full-size version on Astrobin

Final Thoughts

With an effective focal length of roughly 216mm when coupled with a Canon crop sensor body, the field of view is nearly identical to the one you’d find on a full-frame camera with a 200mm telephoto lens. That’s quite a jump from 135mm, so the camera body you use with this lens may change the types of targets you shoot. 

I can’t wait to try this lens out during the winter months on some wide-field targets in Orion. The colder temperatures will make DSLR astrophotography much more practical, and there are plenty of great targets to choose from.

During the frigid months of winter, my motivation to spend over an hour setting up my complete deep-sky imaging rig dwindles. However, stepping outside to polar align a small star tracker and attach a DSLR and lens is quick and painless. 

In these situations, a portable, wide-field imaging rig wins.

Star parties or dark sky excursions are another great time to use a camera lens in place of the telescope. Not only does it let you travel light, but impressive wide field projects are often more successful when captured under a dark sky. 

For those of you that like to “pixel-peep”, have a look at the single image frame captured using the Rokinon 135mm F/2.0 ED UMC at F/4. The image is a 90-second exposure at ISO 400 using a Canon EOS 60Da. The inset picture is a magnified view of the bottom right corner of the frame. 

star test

A single, 90-second exposure using the Rokinon 135mm F/2.0 ED UMC at F/4. 

I hope that this post has provided some practical insight into a popular camera lens for astrophotography. If experience has taught me anything, it’s that the practical, pain-free equipment that gets the most use under the stars. 

This lens is available on Amazon for most camera bodies. Make sure to select your camera mount when checking the price (Check current price). If you have pictures taken using the Rokinon 135mm F/2 lens, please feel free to share your results in the comments section (links to Astrobin, Flickr or your personal gallery are fine). 

List of Compatible Cameras (Mounts)

  • Canon
  • Sony E
  • Fuji X
  • Nikon AE
  • Samsung NX
  • Pentax K
  • Sony A
  • Micro 4/3

Complete Lens Specifications (Canon)

  • Model: 135M-C
  • MSRP: $599
  • UPC: 0-84438-76410-9
  • Focal Length: 135mm
  • Maximum Aperture: F2.0
  • Coverage: Full Frame (FX)
  • Optical Construction: 11 Glass elements in 7 Groups
  • Aperture Range: F2.0 to F22
  • Diaphragm Blades: 9
  • Coating: Ultra Multi-Coating
  • Minimum Focusing Distance: 2.6ft (0.8m)
  • Filter Size: 77mm
  • Lens Hood: Removable
  • Maximum Diameter: 3.2” (82mm)
  • Weight: 29.20oz (830g)
  • Length: 4.80” (122.1mm)

lens construction

Download the User Manual

Helpful Resources:

 

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Using A Canon 300mm Lens for Astrophotography

|Nebulae|9 Comments

If you watched my video about Comet 46P Wirtanen, you may have noticed that my imaging gear included a Canon EF 300mm F/4L USM Lens. This may have seemed a little odd to those that are used to seeing me use a telescope for astrophotography, but a camera lens like this can be a great way to capture deep sky images.

Over the years, a lot of people have asked me why they should invest in a new telescope when they already own a high-quality telephoto camera lens with a comparable focal length. After all, a prime lens like the Canon EF 300mm F/4L isn’t cheap, and its got some seriously impressive optics.

So, if you’ve already got a lens like this in your kit, you should definitely try using it for astrophotography before investing in a new telescope.

Canon 300mm F/4L Lens for Astrophotography

Make no mistake, a telescope designed for deep sky astrophotography has many advantages in terms of deep sky astrophotography. Specialized features such as a robust dual speed focuser, light baffles, and the ability to easily accommodate astronomy cameras and autoguiding systems to name a few.

But if you’ve been into photography for a while, there’s a good chance you’ll already own some camera lenses that are perfect for astrophotography. The secret is, to leverage the tracking abilities of an equatorial mount that allows you to capture long exposure images of the night sky without star trailing.

In this post, I’ll show you how I managed to capture an impressive portrait of the Orion Nebula using a 300mm camera lens from my backyard in the city. I’ll discuss the filter I recommend, the camera settings I use, and the share the process of capturing long exposure images on a tracking mount.

Canon 300mm Prime Lens

My Canon EF 300mm F/4L USM Lens

Canon 300mm F/4L (Non IS)

The camera lens I am using is a first generation Canon EF 300mm F/4L (Non-IS). This is an old L-series lens from Canon that does not include Image Stabilization, but does include the ring type USM autofocus motor. Features like IS and autofocus won’t work for astrophotography, so older prime (non-zoom) lenses like this are a great value in the used market.

It’s quite useful to have prime lenses at different focal lengths in your astrophotography kit. You’ll be able to capture a wide variety of targets from large open star clusters to emission and reflection nebulae like Orion. (See my review of the Rokinon 135mm F/2 for even wider deep sky images).

Video: Deep Sky Astrophotography with a 300mm Camera Lens

I purchased my 300mm F/4L used, and drove a fair distance to meet the seller. The lens was originally intended for bird photography, which I still enjoy today with a 1.4 extender attached for more reach. The native focal length of 300mm and widest aperture are a better configuration for astrophotography purposes. 

The 1.4 x Canon teleconverter introduces chromatic aberration, and I lose a full stop of light (F/5.6).  This is not usually an issue in my daytime photography images, but it’s out of the question when photographing stars.

Using the Canon 300mm F/4L lens on a crop-sensor DSLR (APS-C) camera like my Rebel T3i will effectively create a narrower field of view than a full-frame camera does. This creates an equivalent focal length of 480mm with the crop factor applied (1.6X), which is important to consider when framing up an astrophotography target.

Using a simple FOV (field of view) calculator, you can get a preview of the expected image scale of your target. As you can see, the Canon 300mm F/4L and Canon EOS 600D combo frame the Orion Nebula and Running Man nicely.

camera lens FOV

The Field of View using a 300mm Camera Lens and APS-C Sensor DSLR

Most of the astrophotography telescopes I recommend for beginners hover around the 400mm to 700mm focal length mark, so this camera lens is quite comparable. Also, the Canon EF 300mm F/4L Non IS contains two UD (Ultra low dispersion) lens elements similar to the construction of an apochromatic refractor.

The rather fast optics of this lens (F/4) is advantageous for night photography, as its widest aperture will allow plenty of signal (light) to be collected in each shot. For comparison, my Sky-Watcher Esprit 100 APO has an F-Ratio of F/5.5.

When it comes to acquiring astrophotography data for a healthy signal to noise ratio, a camera lens with a fast aperture is recommended. This is why camera lenses like the Rokinon F/2.8 and Canon F/1.8 are excellent choices for astrophotography.

Focusing the lens

Finding a precise focus using a camera lens is much more difficult than it is with a telescope. Rather than using a smooth dual-speed micro focuser, you have the challenging task of using the rather sensitive focusing ring on the lens (in manual mode of course).

It’s best to point the camera towards a bright object (not a star) to find the initial focus. The Moon, or a distant streetlight will do. Once you have it dialed in using the lenses widest aperture (F/4), you can then aim the lens at a bright star in the night sky using your cameras highest ISO setting. 

From here, it’s a matter of trial and error until you find the sweet spot. Once you’ve found it, be very careful not to bump it out of focus when slewing to your target. You can always fine tune the focusing ring on your deep sky target using short test exposures after.

The Camera: Canon EOS Rebel T3i 

This Rebel T3i (600D) camera has been “modified” for astrophotography, which isn’t nearly as complicated or technical as it sounds. I’ve basically removed an internal filter that blocks certain wavelengths of light from being recorded on the sensor (I didn’t modify this 600D myself, it was done by a professional).

The stock internal IR cut filter found in DSLR cameras like the Canon Rebel T3i creates “normal” looking daytime images, but can hold your astro images back. If you own a DSLR camera that you want to use for astrophotography, look into getting it modded. I waited almost 4 years before making this upgrade, and it significantly improved my astrophotography images.

This modification will better showcase the rich areas of hydrogen gas in the Orion Nebula. For certain deep sky targets (such as the California Nebula) a full-spectrum modified DSLR is essential for a respectable image.

Canon EOS Rebel T3i DSLR

My Full Spectrum Modified Canon EOS Rebel T3i 

The Orion Nebula isn’t one of them! A stock DSLR camera can capture exquisite images of this reflection/emission nebula with beginner-level equipment.

To photograph Messier 42, I’ll shoot a series of 1.5-minute exposures at ISO 400. The images will collect a healthy amount of signal (or light) on this nebula and the surrounding area. With the temperature hovering around zero on the night of acquisition, I benefited from a cool camera sensor that didn’t produce nearly as much noise as I experience in the summer.

Covering the sensor is an Optolong L-Pro filter. This broad spectrum filter is an excellent choice if you are looking to produce natural looking astrophotography images in the city. Light pollution is a big problem for many amateur astrophotographers, and filters like the L-Pro can make your life easier.

This filter clips-into the camera body, and fits neatly underneath the camera lens. Being able to use this filter with either a camera lens or telescope attached is a real bonus. I have also used this filter underneath the Rokinon 14mm F/2.8 lens for some wide angle shots of the night sky from home. 

The Camera Mount: iOptron SkyGuider Pro

The iOptron SkyGuider Pro is the perfect solution for those looking to get started in astrophotography with a DSLR camera and lens. It’s a highly portable, non-nonsense astrophotography mount that allows you to start tracking the movement of the night sky for long exposure imaging.

With the counterweight attached, it can handle heavier lenses like this 300mm F/4L, and even a small telescope like the William Optics Z61.

For this mount to be effective, it must be accurately polar aligned. In the northern hemisphere, we have the advantage of being able to use the north star, Polaris, to help us align with the polar axis of the Earth.

iOptron SkyGuider Pro

The iOptron SkyGuider Pro Camera Mount

To start tracking, its a simple as turning the SkyGuider on, with the mode set to 1X sidereal rate. After that, the camera mount slowly matches the apparent rotation of the night sky, and my long exposure images record pin-point stars without trailing.

The SkyGuider pro includes an illuminated reticle that you can use as a guide to align the mount. This make it really easy to get your alignment just right – which is critically important for astrophotography. Polar alignment and balance will make the biggest impact on your images.

The farther off you are in either area (balance and polar alignment), the shorter your exposure times will need to be. With a sound polar alignment and a careful balance, unguided exposures of 3 minutes or more are no problem on the iOptron SkyGuider Pro mount.

Locating Objects with the SkyGuider Pro

To locate and frame a deep sky target using this mount, it must be done manually (no GoTo functionality). For bright targets like the Orion Nebula, this is extremely easy, as I can line up the target using the viewfinder on my DSLR camera. For faint targets, or when using a narrowband filter, you may need to take a number of test exposures to get it framed just right.

I personally have the SGP mounted to a lightweight carbon fiber tripod. This is a highly portable configuration, but it’s likely a little too flimsy for folks that want a rock-solid platform. Consider using a more robust aluminium tripod with this mount.

The Target: Orion Nebula

The bright moon certainly isn’t helping me capture the faint dusty details surrounding Orion. Luckily, M42 is such a bright deep sky object that it can be enjoyed in less than perfect conditions. I’ve photographed this target so many times, and it never gets old.

It’s a spectacular target to test new equipment on, because you are bound to get a rather impressive image no matter which approach you take. The light pollution filter used (Optolong L-Pro) did a great job of reducing the unwanted artificial light present in my backyard, allowing the natural star colors to shine through.

To create my final image, I’ve stacked the individual exposures together using a free software called DeepSkyStackerThe resulting was then brought into into Adobe Photoshop for further processing. If you want to learn how I process my astrophotography images, have a look at some of the image processing tutorials I’ve shared in the past.

Orion Nebula 300mm Camera Lens

The Orion Nebula captured using a Canon EF 300mm F/4L Lens (Click for larger version)

Image Details

  • ISO Setting: 400
  • Exposure Length: 90-seconds
  • Number of Exposures: 117
  • Total Overall Exposure: 2 Hours, 49 Minutes
  • Support Files: 15 Darks, 15 Flats, 15 Bias
  • Image Processing: DeepSyStacker, Adobe Photoshop

The Bottom Line

As you can see in my image above, the stars are sharp and free of chromatic aberration (color fringing). This is a testament to the high quality optics of the 300mm F/4L lens, and an important factor to consider when choosing a camera lens for astrophotography.

Capturing sharp, accurately colored stars is the ultimate challenge for optical equipment, and the Canon EF 300mm F/4L passes with flying colors. The field is also extremely flat, another trait of only the best camera lenses. 

A prime telephoto camera lens like the Canon EF 300mm F/4L is a great way to capture deep sky astrophotography images, as long as you’ve got a way to track the night sky for each shot. The wide field of view is very forgiving, meaning autoguiding isn’t necessary for a successful long exposure image.

Whether you’re using a camera lens, telescope, or a pair of binoculars. I hope you’re able to get out and appreciate the impossibly beautiful history of our universe that shines above our heads this season.

Until next time, clear skies.

Helpful Resources:

Astrophotography Cameras – What’s the Best Choice for Beginners?

Examples using a Canon EF 300mm F/L Non IS for astro imaging (Cloudy Nights)

How to Make a Bahtinov Mask for Your Camera Lens (Deep Sky Watch)

 

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The Best Lens for Astrophotography (That You Probably Already Own)

|Camera|10 Comments

In my opinion, the best astrophotography lens is one that can capture a variety of images of the night sky in a reliable and consistent way. Not all camera lenses are created equal, and imaging a night sky full of pinpoint stars has a way of bringing out the worst (or best) of your lenses capabilities.

In the following post, I’ll share my experiences using 2 astonishingly affordable camera lenses for astrophotography. I shoot with both full-frame and APS-C sized sensor Canon DSLR’s, so the lenses are both made by Canon. The Canon EF 50mm F/1.8 STM, and the Rokinon 14mm F/2.8 wide angle lens.

It’s not possible for me to recommend a single “best lens for astrophotography”, as that title will vary depending on who you ask. Consider this post to offer some real-world advice from someone who’s pointed several cameras and lenses towards the night sky over the past 8 years.

The Best Lens for Astrophotography (You May Already Own)

camera lens for astrophotography

The Canon EF 50mm F/1.8 Camera Lens and DSLR on a Tracking Mount

The truth is, when I look at similar reviews for astrophotography lenses, they tend to focus solely on Milky Way photography, and nightscapes. Unlike most reviewers, my long history in deep sky astrophotography using a DSLR through a telescope has given me a unique perspective on this subject.

On a recent astrophotography session in the backyard, I discovered how enjoyable it can be to squeeze in a brief mid-week session using my camera lens in place of the telescope.

For this imaging run, I used the refreshingly simple and affordable Canon EF 50mm F/1.8 lens. The lens was attached to my Canon Rebel T3i DSLR, which rode atop an iOptron SkyTracker camera mount.

(Those of you that have been following my blog for some time know how much I love my DSLR astrophotography.)

The difference this time around is that I’m able to get up and running in about 10 minutes.  The lack of computer control and autoguiding saves a lot of time and effort – meaning I’m collecting data sooner.

Don’t believe me? Have a look at a recent shoot that took place on a less than perfect night.

A Budget Astrophotography Lens (Nifty Fifty)

The lens used in this video is often referred to as the “nifty fifty”. “Every photographer should own a 50mm f/1.8 lens as your first upgrade from the kit lens that came with your camera.”Improvephotography.com

In the video above, I set out to capture the Orion Constellation using a Lens in place of a telescope.  This is my “quick and dirty” imaging setup.

Using a Camera Lens instead of a Telescope

On nights when imaging time is limited, a great option is to set up a highly mobile setup that you can get up and running quickly. You do not need a telescope to enjoy astrophotography and capture many stunning deep sky objects in the night sky.

Related Post: 7 Astrophotography Tips and Camera Settings You Can Try Tonight.

Sure it would be great to capture light frames on a deep sky project using my primary imaging telescope, but that’s not always a practical choice in the middle of February. Setting up a DSLR camera and lens on a portable tracking mount is quick and painless – and I still get my astrophotography fix.

Setting up my camera mount

A small sky-tracker camera mount can be set up and polar aligned within minutes

The process of setting up my complete deep sky telescope rig for a night of astrophotography takes time.

Even with a sound blueprint for setting up my non-permanent setup, the process can take upwards of an hour. This isn’t a problem on a warm Saturday in June, but a Monday night in February is an entirely different experience.

Another factor that went into consideration was the weather conditions for that particular night. The clear sky chart was less than ideal, with the transparency meter looking a little pale.

Rather than setting myself up for a potentially wasted night due to weather, I took a chance on some wide field shots using my “spur of the moment” rig. If the clouds did end up rolling in, I could quickly pack everything back up into the garage in minutes.

A Lightweight, Portable Solution

wide-angle astrophotography setup

My Canon EOS Rebel T3i sitting atop the SkyTracker Pro Camera Mount

The iOptron SkyTracker Pro is a portable astrophotography mount that is perfect for taking wide-angle nightscape with a DSLR camera and lens. If you’re just getting into the hobby and interested in long exposure shots of the Milky Way – a star tracker mount like this what you want.

My target on this particular night was the Orion Constellation, including Barnard’s Loop. Using the Canon 50m lens with my T3i results in a focal length of 80mm (50mm x 1.6 crop factor), which happens to be a perfect fit when it comes to capturing the stars that make up Orion the hunter.

Canon astrophotography lens

The Canon EF 50mm F/1.8 Lens

What’s the Best Lens for Astrophotography on a budget?

You may remember my announcement on Facebook about investing in a new Rokinon 14mm F/2.8 lens. This “budget” category lens was purchased with the idea of wide-angle nightscapes in mind.

There are many great lenses for astrophotography available, but these are two that I personally own and enjoy. The models mentioned below are both prime lenses with a fixed focal length. Although they are both affordable choices for astrophotography, their uses will vary.

Jerry Lodriguss has put together a helpful list of both Canon, Nikon, Sigma and Rokinon Lenses for Astrophotography on his website.

best budget astrophotography lens

Left: Rokinon 14mm F/2.8  |   Right: Canon 50mm F/1.8

The lenses listed below are both built for a Canon DSLR body because that’s what I currently shoot with.  Nikon has comparable lenses (Nikkor) in this category, with similar models of the lenses mentioned below.

The Rokinon 14mm F/2.8

If you were to ask me for advice on “the best budget lens for astrophotography”, I’d lean toward the Rokinon 14mm Ultra Wide Lens if you plan on shooting wide-angle astro-landscapes.  Over the summer of 2018, I was able to capture some incredible images of the night sky with this lens.

Rokinon 14mm F/2.8 lens for Canon

The Rokinon 14mm F/2.8 Lens attached to my Canon DSLR

At 14mm, the Rokinon is a much better choice than the Canon 50mm if you plan to capture large areas of the night sky, including the Milky Way. With a full frame camera, the ultra-wide 14mm FOV can be fully appreciated.

Pros:

  • Ultra Wide-Angle (Especially using a full-frame DSLR)
  • Affordable
  • Fast Optics (F/2.8)

Cons:

  • Manual aperture adjustment
  • The manual focus ring is slow
  • Big and bulky objective lens

As the season changes, I’ll spend much more time with this astrophotography lens.  I am curious to see how much sky I can collect in some stacked long exposures.

Update: Summer 2018

I used the SkyTracker Pro mount and the Rokinon 14mm F/2.8 Lens to photograph the Milky Way under the dark skies of Cherry Springs State Park in June 2018. This portable astrophotography setup is absolutely perfect for wide-angle shots of the Milky Way.

The Milky Way

The Milky Way using the Rokinon 14mm F/2.8 Lens

If you’re want to go a step further and use a small telescope – I’ve had success using the beefier SkyGuider Pro. Wide-field nightscapes are a lot of fun – and can be just as rewarding as a deep sky image. The SkyTracker taps out after the weight of a DSLR camera and modest size lens.

The Canon EF 50mm F/1.8

This lens is about $150 brand new, is virtually weightless, and is useful focal length for wide field imaging on certain targets.  I purchased the Canon EF 50mm F/1.8 lens years ago, as it added a much need portrait lens to my DSLR kit at the time.

Canon EF 50mm F/1.8

With the aperture wide open at F/1.8, you can pull in a lot of light in a short period of time, but the stars are a little rough at the edges of the frame. If you stop down to F/2.8 or F/3.2 things improve dramatically.

Pros:

  • Extremely Affordable
  • Fast Optics (F/1.8)
  • Lightweight

Cons:

  • No Image Stabilization
  • Impractical Focal Length
  • Stars at F/1.8 aren’t great

examples using a 50mm lens

The images above were taken by Kurt Zeppetello and Victor Toth using the Canon 50mm F/1.8 lens on a tracking mount.

Camera LensFocal LengthMax ApertureBest F-Ratio to UseBest ForPrice
Rokinon 14mm F/2.814mmF/2.8F/3.2Wide Deep-SkyCheck Amazon
Canon EF 50mm F/1.850mmF/1.8F/3.2The Milky WayCheck Amazon

Using a Clip-in DSLR filter with a camera lens

To make life easier, I opted to use an h-alpha filter in the T3i to completely ignore the light pollution from home. The Astronomik 12nm Ha filter clips into my camera – and isolates the hydrogen gases found within the hunter.

I don’t recommend using a thread filter that screws on to the objective of your camera lens. It’s best to use a clip filter that clicks into the body of the DSLR underneath the lens, like the one shown below.

The clip-in style filters allow you to attach any EF mount-style lenses to your Canon camera. I recommend double checking to see if your lens is compatible with a particular clip filter before purchasing.

Clip-in DSLR filter

The Astronomik 12nm Ha Clip-In Filter used for my Narrowband image of Orion

The Orion Constellation at 50mm (in narrowband ha)

The following image is of a large portion of the night sky including the stars and nebulae surrounding Orion. I use the hydrogen-alpha clip filter in my camera on nights when the Moon is out, or I simply want to capture some dramatic details in a particular nebula.

The resulting narrowband image is, of course, black and white – with the red channel isolated in photoshop for processing. For more details on processing images in ha from a DSLR, have a look at my narrowband Photoshop tutorial.

Barnard's Loop in Orion

Barnard’s Loop in Orion | 26 x 3-minutes @ ISO 800

Overall, I am quite pleased with the way this turned out. The total exposure time was short, and the sky conditions were lousy. The focal length of the Canon EF 50mm lens was spot on for a constellation of this size.

The shots were 3 minutes each, at ISO 800.  I stopped the aperture down to F/3.2 to sharpen things up, not to mention not blow out my 3-minute subs. As you can see, the stars are still rather sharp at the very edge of the field.

stars at the edge of field

A sound polar alignment on the little iOptron SkyTracker was all I needed for sharp, pinpoint stars for each 180-second sub.  Can your telescope mount go 3 minutes unguided with sharp stars?

To polar align, I simply refer to my Polar Finder phone app and make the necessary adjustments to the mount.

At this focal length, autoguiding is not necessary and the field of view is quite wide and forgiving. With that being said, I am so impressed with the smooth and accurate tracking on the SkyTracker. A camera mount like this opens up new opportunities for night photography when using a camera lens for astrophotography.

Camera Automation and Focus

I  automate my imaging sessions on the SkyTracker mount using a remote shutter release cable that connects directly to the DSLR. With this device, I can set everything from the number of exposures to the individual exposure length.

A typical astrophotography imaging session will include 30 images of 90-seconds or more, with a 5-second delay between shots. It’s often said that using a delay can help let your camera sensor cool down a bit between shots. This will help reduce noise.

remote shutter release cable

My Polaroid  Remote Shutter Release Cable

The cheap Polaroid version I bought on Amazon has been surprisingly reliable. Using the remote, I let the camera do it’s thing until it’s time to tear down and go to bed.

The photo below showcases the constellation Cygnus and the Milky Way using my Canon T3i DSLR with the Rokinon 14mm F/2.8 Ultra wide angle lens. It’s a stacked shot of 23 x 2-minute exposures.

The Summer Triangle

The Summer Triangle and the Milky Way (Rokinon 14mm F/2.8)

The Best Lens for Canon DSLR’s

I would like to recommend the Canon EF 50mm F/1.8 STM and the Rokinon 14mm F/2.8 Ultra Wide Angle lenses for Canon cameras. These 2 lenses are tremendous choices for astrophotography because they are capable of letting in a lot of starlight in a single exposure.

The 50mm is a useful focal length for framing up a particular constellation like Orion, above. While the Rokinon 14mm lens is perfect for shooting the Milky Way. Both lenses can produce sharp results and impressive images when the correct settings and techniques are used.

The Canon EF 24-105mm F/4 lens has also been useful for certain projects. It’s a zoom lens, but the star quality is commendable at both 24mm and 105mm. When coupled with a crop-sensor DSLR, the full magnification of 105mm brings a new perspective to popular targets such as the Horsehead and Flame nebula in Orion.

iOptron SkyTracker Pro Camera Mount

Deep sky objects in Orion at 105mm (Canon EF 24-105mm F/4L lens)

For me – finding ways to sustain this hobby long term is important. This rather brief astrophotography session provided me with enough data to produce an impressive portrait of Barnard’s Loop, and the Orion constellation in hydrogen alpha.

The simplicity of mounting the camera on a small tracking mount and walking away really appeals to me.  On frigid February night, it’s a refreshing experience that doesn’t involve a lengthy star alignment routine or lugging 40 pounds of gear around.

Shooting deep sky through a telescope will always be my bread and butter, but shooting with a cheap astrophotography lens on a small star tracker sure is a lot of fun too.

Related Posts:

Astrophotography Cameras: The Best Choice for a Beginner

Light Pollution Filters for Astrophotography

Deep Sky Astrophotography with a 300mm Camera Lens

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