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William Optics RedCat 51 (First Look)

|Telescopes|20 Comments

William Optics is a company known for creating high performance apochromatic refractors, and constantly updating and refining their designs. The RedCat 51 Petzval APO is the latest creation from the company that can’t sit still, and it is bound to shake up the industry once more.

I am fortunate enough to have been granted early access to this exciting Petzval apochromat that debuts in early March 2019.

What makes the William Optics Redcat 51 so special? The 4-element Petzval design, unique focal length and helical focuser. The sleek red finish of the RedCat 51 signals its individuality and charm. It is unlike any other astrophotography telescope on the market, and one that I have been waiting to get my hands on since reviewing the early concept designs last year.

While shooting the unboxing video for the RedCat, I came to the conclusion that this is hands down the most beautiful looking telescope I have ever seen in terms of style and design. This is a signature quality of the William Optics brand and they continue to push the envelope with new and dramatic concepts.

The William Optics RedCat 51

The design goals for the RedCat included creating an affordable refractor that uses the highest quality glass, and delivers a flat imaging field with unmatched color correction. In this post, I’ll break down the specifications of the RedCat and explain why I think this little quadruplet will be one of the most sought after products in 2019.

Have you ever seen a more dramatic video for an astronomy product in your life?

The RedCat bridges the gap between an astrophotography telescope and a telephoto lens.

prime lenses

The 250mm focal length and F/4.9 focal ratio mean that the RedCat can be enjoyed as much by wildlife photographers as it is by amateur astrophotographers. The helical focuser makes focusing a fast-moving targets such as birds much easier than ever before.

For those of you that don’t know, I am also an avid bird photographer. Once I discovered the clarity and sharpness provided by a apochromatic refractor telescope, I began using my astrophotography telescopes for bird photography. These telescopes were too heavy to use handheld, and were challenging to focus on moving subjects.

Roughly 8 years later, William Optics releases a high-end apochromatic refractor that targets the wildlife photography market. The RedCat encapsulates two of my greatest passions (astrophotography and bird photography) in a single product.

The RedCat 51 is small, beautifully designed, and versatile. The early astrophotography image examples shared by William Optics are breathtaking. Aside from looking good, and some promising looking results in terms of performance, the RedCat 51 has some handy features to improve the user experience.

Before I cover items such as the filter slot and modular mounting options, let’s dive into the core specifications of the RedCat 51.

RedCat 51 Specifications:

  • Optical Design: Petzval Apochromatic Refractor (4 elements in 3 groups)
  • Lens Type: Prime
  • Diameter: 51mm
  • Focal Length: 250mm
  • F-Ratio: F/4.9
  • Weight: 3.2 lbs
  • Focuser: Calibrated Helical
  • Mounting Style: Vixen/Arca-Swiss

RedCat 51 mounted to an iOptron SkyGuider Pro

The RedCat 51 mounted to an iOptron SkyGuider Pro.

Focal Length: 250mm

First off, the RedCat 51 has a focal length of 250mm. What does this mean for astrophotography? It means extremely wide-field deep sky images. If you consider a 480mm refractor to be a wide-field ‘scope, the RedCat is nearly twice as wide!

Massive deep sky objects such as the Carina Nebula will fit into the image frame in their entirety. Large nebulae that traditionally fill the frame in a typical wide field setup are captured with plenty of surrounding space and additional star clusters and nebulae in the frame.

Until the RedCat came along, 250mm was a focal length reserved for those that employ a prime camera lens for astrophotography. Now amateur astrophotographers have the option of using a flat-field APO that easily mounts to their existing equatorial mount for deep sky imaging at this magnification range.

For wildlife photography, this focal length is also quite useful, especially when you consider the all-important f-ratio of this lens. 250mm is enough reach for many larger birds such as hawks and owls, but will require a steady hand and gimbal head for the best chance of a sharp shot. 

For nature and wildlife photography, the RedCat 51 has a minimum focus distance of 3.7 meters. This can be improved to under 3 meters with the use of the 2″ extension nose piece from the diagonal. By adding even more extension tubes, the RedCat can even be used for macro photography of small insects. 

William Optics RedCat 51 APO

The FPL-53 Objective lens of the RedCat 51 Petzval APO.

Focal Ratio: F/4.9

When it comes to photography (of filming) birds, it’s all about light. Fast shutter speeds are required to capture a bird in motion, and this demands a fast lens to adequately expose the shot. F/4.9 isn’t incredibly fast in the world of camera lenses, but when you consider that this is essentially a refractor telescope – it’s about as much light gathering power as you’ll find on the market.

For comparison, the RedCat is almost a stop faster than the extremely popular Canon EF 400mm F/5.6L lens. William Optics has released some incredible wildlife footage shot using the RedCat, a testament to this quality. Low light situations such as a cloudy day, made wildlife photography tough with my old F/6 William Optics Z72. The speedy RedCat is a completely different animal.

51mm Lens Diameter

As the name eludes to, the RedCat has a 51mm objective lens. In the world of astrophotography telescopes, this is absolutely tiny! If you thought the adorable little Zenithstar 61 was cute, wait until you see the RedCat. But this kitten has claws (I couldn’t resist).

The 51mm objective lens on the RedCat is made from top quality FPL-53 and FPL-51 glass (synthetic fluorite) which creates a flat frame image from corner to corner, even when utilizing the entire image circle with a full frame camera.

The small size of the RedCat means keeping overall weight to a minimum, despite the extra glass. The RedCat 51 weighs only 3.2 pounds even through the design requires 4 elements in 3 groups. For owners looking for a high-end telescope to mount on the iOptron SkyGuider Pro, the RedCat is an ideal candidate.

Lens Structure: Petzval

A Petzval lens design involves a low-dispersion doublet in combination with two elements farther down the optical path to both speed up the f-ratio of the telescope, and flatten the image field. There is no need to use a field flattener with the RedCat, adding to its simplicity and practicality in the field.

Petzval Lens Design

The Petzval quadruplet lens design is well corrected, and incredibly sharp. You can expect pinpoint stars to edges of your image. If you don’t believe me, have a look at this image of the Witch Head Nebula taken using the RedCat 51 by Mehmet Ergün.

These traits will surely make the RedCat a popular choice for high resolution deep sky astrophotography imaging. Portability and design aside, the RedCat is an affordable option for those looking to own a top-of-the-line astrophotography telescope. A comparable refractor on a much larger scale is the Takahashi FSQ106.

RedCat 51 example images

Example images taken using the William Optics RedCat 51 on Flickr.

In mid February 2019, Wei-Hao Wang shared an incredible image of the Running Chicken Nebula using the RedCat 51 with a modified Nikon D800 on Astrobin. The full size image really showcases the color correction and flat-field qualities of the optics. 

I had a chance to test the RedCat 51 on the night of the full moon. This is not an ideal time to capture deep sky objects in boradband true color,  so I used an Optolong 7nm Ha filter inside of the RedCat. The image below was captured using a modified Canon EOS Rebel T3i (600D) through the RedCat 51 APO.

I stacked 33 sub exposures of 4-minutes @ ISO 1600 each to create a total integrated exposure of 2 hours and 12 minutes. The 4-minute sub exposures were accomplished thanks to the accurate tracking of the iOptron SkyGuider Pro. 

rosette nebula redcat 51

The Rosette Nebula in Ha – RedCat 51 + Canon DSLR

Helical Focuser

Yes, a helical focuser! This design aspect is completely changes the user experience of the RedCat, whether you use it to photograph the night sky, or a Black-crowned night heron. I have used a number of apochromatic refractors for daytime photography in the past, but none of them felt natural because of the of rack and pinion focuser.

Aside from the impressive lens design, the helical focuser is the single biggest differentiating factor between the RedCat and a typical imaging APO. The focuser draw tube is calibrated and features printed mm spacing marks for precise adjustments. The black textured focuser ring is made out of soft rubber for a comfortable grip.

Adjusting focus during frantic wildlife photography moments is now much more fluid and responsive, while the precision and rigidity needed for deep sky astrophotography is retained. The focuser tension ring allows you to precisely control the level of friction desired, and also can also lock the tube in place when needed.

astrophotography examples

Some of the deep sky images I have captured using the William Optics RedCat 51 and a DSLR camera.

Field Rotator

The field rotator resembles the face of a luxury brand watch, which is exactly the inspiration William Optics used when designing the rotator markings on the RedCat. Every degree of the field rotator is marked to help aid in the process of creating a mosaic. There is a small white arrow on the M48 adapter to use as a reference point when setting your camera orientation.

This level of attention to detail is noteworthy, as this subtle feature indicates input from actual amateur astrophotographer needs.

You’ll find that many of the hidden “extras” on the RedCat 51 follow this mindset as well, including the small white teflon rings inside of the mounting ring. This small, yet thoughtful detail allows the user to smoothly rotate your imaging train. 

M48 fied rotator

The field rotator includes markings for each each degree of rotation.

M48 Thread

The M48 thread adapter allows you to fasten your DSLR or dedicated astronomy camera to the RedCat for astrophotography or daytime photography. The imaging circle completely covers a full frame camera sensor for edge to edge illumination with a flat-field.

Speaking of covering your camera sensor, the M48 adapter includes an internal thread for 48mm (2-inch) threaded filters. This is a convenient location to place your favorite light pollution or narrowband astrophotography filter.

Owners of Canon, Nikon, Sony or Pentax cameras will be happy to know that their camera bodies are a perfect fit for the RedCat with the necessary t-mount and adapter hardware. The M48 end adapter must be removed to apply the matching red William Optics erecting diagonal.

telescope

Mounting Base and Lens Collar

The base of the RedCat 51 was specially designed to avoid adding extra weight to the telescope, yet provides a reliable platform for the the demanding positions of astronomical imaging. The matching red low profile dovetail bar can be used with either a standard Vixen mount saddle, or the photography based Arca-Swiss style mounting bracket.

The dovetail plate includes standard ¼ inch threads, and simply needs to be flipped over to accommodate your desired mounting configuration. Deciding on the configuration of this aspect of the telescope will depend on your primary use of the RedCat.

The optical tube itself can also rotate easily thanks to the lens collar and release knob. This is similar to the design you’ll find on high end telephoto camera lenses, but with 2 extras.There are modular mounting options on the lens collar. Here, you can fasten accessories such as a shotgun microphone or red dot finder scope.

Integrated Bahtinov Focusing Mask

To top things off, William Optics has included their signature diffraction spikes Bahtinov mask in the lens cap. This feature is handy for DSLR astrophotography imaging sessions when you need to quickly and accurately confirm the focus of your target. You simply need to aim the telescope towards a bright star to create the diffraction spike pattern.

The elongated star patterns displayed when pointed at a bright star create an obvious and distinct guideline to reference when using adjusting the helical focuser. The clear acrylic design of these masks make them much easier to use than the traditional opaque black Bahtinov masks. 

star spikes bahtinov mask

You may have also noticed the color matched steel William Optics Vixen style base attached the iOptron SkyGuider Pro. This base mount also fits the Sky-Watcher Star Adventurer, and adds some serious stability to and improved aesthetics over the original base. The package also includes a 4.5″ red extension bar for the counterweight, that I regretfully forgot to install before filming the video.

Comparable Telescopes

You may be asking yourself if there are alternatives to the RedCat to consider, with a comparable optical design and size. Although the Vixen FL55 does not share a Petzval design, it is an ultra-wide field fluorite refactor with a 55mm lens diameter. The focal length of the Vixen FL55 is 239mm, with a focal ratio of F/4.3 (with the optional reducer used). The Vixen model does not include a carry case, Bahtinov mask in the price, and requires an additional reducer for maximum usefulness.

The Takahashi FS-60 CB is also a direct competitor of the RedCat, although its design mirrors the WO Z61 more so than the RedCat 51. This is another compact fluorite refractor, and features a focal length of 335mm, at F/5.9.  The Takahashi name carries with it a  premium price. This optical performance of this 60mm refractor is indeed impressive, yet it does not have the unique features of design of the RedCat in a complete package.   

RedCat alternatives

RedCat 51 Alternatives, the Vixen FL55 and Takahashi FS-60CB.

Autofocus

When I mentioned that the RedCat 51 can be used as a  daytime wildlife photography lens, you may have wondered whether the RedCat will work with the autofocus function of your DSLR. I have some good news. Yes, the RedCat 51 can be used with autofocus!

But there is a catch (two actually). You will need to use the TechArt Pro adapter that includes a built in motor for manual lenses. This system only works with certain Sony DSLR cameras, which means for Canon or Nikon shooters, you’ll have to make due with manual focusing of the RedCat 51.

The system relies on the phase-detect autofocus system found on modern Sony cameras such as the Sony a6300, a6500, A7ii, and A7Rii.

autofocus with RedCat

The RedCat mounted to a Sony a7R and the TechArt Pro adapter.

Accessories

The package William Optics sent to me included a number of extras, including the Canon EOS T-Mount adapter, and the dedicated erect image diagonal. The diagonal will hold a 1.25″ eyepiece for visual observing, or spotting scope purposes. The Canon EOS T-ring included with the RedCat is the most stylish looking camera adapter I have experienced to date.

The diagonal is of little importance to those that will use the RedCat 51 exclusively for deep sky astrophotography, but it is a nice option for those that like the choice of using this telescope for visual use. This is of particular interest to anyone who purchases the RedCat with plans on using the telescope as a spotting scope for wildlife photography.

The RedCat can be mounted to a traditional photography tripod for crisp views at 250mm. 

Erect image diagonal

The dedicated RedCat erect image diagonal fastened to the telescope.

Removing the M48 Adapter

To install the dedicated erect image diagonal on the RedCat 51, you need to remove the 48mm adapter. Use a small Allan key (0.7mm) to unscrew the three grub screws just enough so that you can turn the M48 adapter counter-clockwise with the field rotator locked. You should eventually feel the thread release so you can unscrew the adapter.

48mm filter for RedCat

Remove the M48 Adapter on the RedCat to fasten the diagonal or install a 2-inch filter.

The diagonal can then be threaded directly to the base of the field rotator for visual observing or spotting scope purposes.

The 48mm filter threads are also located between the M48 adapter and the field rotator. This is a discreet location in the imaging train to thread a light pollution filter inside of the RedCat 51.

The Bottom Line

The price tag of the William Optics RedCat 51 may seem a bit steep at first, but considering the pedigree of this refractor, it’s right on the mark. Creating an affordable option for those looking for a premium imaging APO in small package was the overall goal of the RedCat design. I believe the RedCat is poised to have a big year, and look forward to the official unveiling at NEAF. 

If you have interests in both wildlife photography and deep sky astrophotography as I do, you might feel like the RedCat was designed specifically for you. William Optics is brand that continues to innovate and create original products. In in world full of copycats, this little APO stands in a category of it’s own. 

This telescope will be available in early March 2019. You can order the William Optics RedCat 51 at High Point Scientific

High Point Scientific

See the RedCat 51 in action on YouTube: Deep Sky Astrophotography with the RedCat 51

 

Related Posts:

William Optics RedCat 51 Official Product Page

William Optics Zenithstar 73 APO Review

Astrophotography in Costa Rica (Carina Nebula)

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The Explore Scientific ED140 Apo Refractor

|Telescopes|6 Comments

I am thrilled to tell you that I recently got my hands on a brand new Explore Scientific ED140 CF APO Triplet Refractor. If you’ve been following AstroBackyard for some time now, you’ll know how I feel about APO refractors in terms of astrophotography performance.

The refractor telescope design has many unique advantages when it comes to deep sky astrophotography. Specifically, an air-spaced triplet apochromatic optical design will share many of the same characteristics you’ll find on a high-end telephoto camera lens. The biggest difference is – they usually reach much further. (The ED140 has a focal length of 910mm)

The Explore Scientific ED140 CF

I won’t tell you that you need a 140mm refractor to enjoy deep sky imaging, because that’s simply not true. Instead, look at my experiences with this telescope as a window into the possibilities that await you in the future. By the time you have outgrown your little astrophotography telescope, maybe you’ll consider stepping up to the stunning Explore Scientific ED140 triplet apochromatic refractor.

I met up with the team at Explore Scientific last month at NEAF – and they asked if would try out their new ED140. Would you turn an opportunity like that down?

I didn’t.

In the video above, you’ll see me use the ED140 to capture a deep sky astrophotography image from my backyard. I decided to choose a target that could be completed in one night, using a one-shot-color camera. The great globular cluster in Hercules (M13) is a fitting choice for an incredible telescope like this, and the first globular cluster I’ve ever shot on my YouTube channel.

The Apochromatic Refractor Advantage

Before I get into the details of this giant APO, I’ll provide a little bit of backstory.

Back in 2011, I started using an Explore Scientific ED80 F/6 refractor.  For many years, I was thrilled with the images I was taking using the ED80 and a DSLR camera. If you like shooting wide-field targets such as the North America Nebula, the Andromeda Galaxy or the Pleiades, a small apochromatic refractor telescope like this is a superb choice.

using a refractor telescope for astrophotography

My early deep sky images using an Explore Scientific ED80 Triplet APO.

The only thing you’ll be missing out on with a small telescope of this size is the visual observing power and increased magnification that comes with an instrument with a larger aperture. A refractor in the 60-100mm range generally offers an extremely wide field of view, which is great most of the time.

If your primary interests lie in objects that require high magnification and light-gathering ability such as planets, you may want to think about a larger telescope. Photographing small galaxies, globular star clusters and solar system targets are not a small APO’s strong points.

The lack of chromatic aberration, coma or need for constant collimation make the refractor design my absolute favorite type of telescope design when it comes to deep sky astrophotography. However, to get the extra light gathering power found in larger telescopes, expect to pay a lot more per inch of aperture.

An F/6.5 Carbon Fiber Monster

A large refractor like the Explore Scientific ED140 not only offers the image quality and performance APO owners expect but also the reach and resolving power needed to capture planets and smaller deep sky objects. 5.5″ inches of aperture gives you the light-gathering power needed to soak in the delicate fine details of objects in space.

carbon fiber telescope

The carbon fiber tube of the ED140 is lightweight and strong

In my opinion, you can’t fully appreciate the additional aperture from a telescope like this without gradually working your way up in size. As I mentioned, I’ve had the pleasure of taking astrophotography images with many sizes of refractor telescopes – everything from a 61mm telescope to a 132mm. This has given me with some practical perspective about the difference extra aperture makes when it comes to astrophotography.

The Explore Scientific ED140 CF Triplet APO now holds the title of the absolute biggest refractor telescope I have ever used for astrophotography.

Core Specs:

  • Focal Length: 910mm
  • Focal Ratio: f/6.5
  • Tube Length w/ Dew Shield: 991mm
  • Diameter: 140mm
  • Weight: 21 lbs
  • Dovetail: Vixen

Explore Scientific ED140 CF Triplet APO refractor telescope

First Impressions

The first thing I noticed when I picked up the box, was how light it was. The Explore Scientific ED140 is noticeably light for its size, no doubt due to its carbon fiber construction. Despite being 8mm wider in aperture, this telescope is roughly the same weight as the William Optics FLT 132. The Carbon fiber tube doesn’t sacrifice strength for a lighter payload either. This versatile material is extremely strong and is also said to compensate for temperature fluctuations better than a steel tube.

Explore Scientific logo

With my gear staying outside in a non-insulated garage – I’ve never really had any issues waiting for my telescopes to cool down/warm up. However, I understand that this is something to consider for many amateur astrophotographers. I’m a big fan of the way this telescope looks, and not just because it matches my ED102. For those that appreciate aesthetics, the finish on this instrument is a real head-turner at star parties.

What’s Included?

As I have mentioned in the past, the accessories included with astrophotography telescope packages vary widely. Some will include everything from a dedicated field flattener to the guide scope, while others may not even include the mounting hardware and sell the optical tube on its own.

The Explore Scientific ED140 F/6.5 APO Triplet includes some impressive extras in their standard package.

Heavy Duty Carry Case

The first thing you’ll notice when you take this giant telescope out of the box is that it comes with a heavy-duty hard carry case. This looks identical to the case that came with my Explore Scientific ED102 CF – which has come in very handy when traveling with the scope. This case was rugged enough to get packed into my trunk with lots of heavy camping gear on top.

The carry case comes with a thick padded-foam insert that holds the ED140 securely. For those planning on traveling with the ED140 – this case is TSA approved.

hard carry case

The hard carry case is heavy duty and TSA approved

2″ Diagonal for your eyepieces

The ED140 telescope includes an Explore Scientific branded 2″ diagonal in the hard carry case. A diagonal reflects the image through the telescope on a 90-degree angle to provide a more comfortable experience using an eyepiece. This is an essential accessory for anyone who plans on using this telescope for visual use.

I have only ever used one diagonal before this one, and it was also an Explore Scientific “99% reflective” model. I must admit, I have not taken the diagonal out of the case yet, nor have I used the Ed140 for any visual observations yet.

In terms of visual performance, the large aperture and fast focal ratio (F/6.5) of this telescope mean that impressive views of both deep-sky objects and solar system objects are possible under the right sky conditions.

It’s not clear how long I’ll have this telescope for, but I’d love to test it out under the dark skies of Cherry Springs State Park next month.

Heavy-duty 3″ Hexagonal focuser

The 3″ hexagonal focuser is big and rigid, which is what you’d expect on a telescope of this size and price point. No doubt, most will use the ED140 will primarily be used for astrophotography, so it’s reassuring to know that Explore Scientific rates this focuser at a 10-lb payload. My camera gear is nowhere near that weight, but owners of large CCD cameras and filter wheels will appreciate this payload rating.

With the ZWO ASI294MC-Pro camera attached, I was easily able to find focus using this ultra smooth 10:1 dual speed focuser. Once locked, there is no “play” in this focuser. Meaning, no surprises while imaging due to the focuser shifting or jarring the camera.

3 inch hexagonal focuser

The 3-inch dual-speed hexagonal focuser on the ED140 is solid

Cradle Ring with Handle and Dovetail

Mounting the ED140 is easy due to the included cradle rings and Vixen-style dovetail plate. I really like this design, and it’s the same mounting style used on the 102mm version. Aside from making the telescope easier to manage, the handle portion is a great spot to mount an additional finder scope, center the guide scope, or attach a ball head and camera lens.

In the past, I’ve mounted a DSLR camera and heavy 300mm F/4L lens to the handle of the cradle rings. The 1/4″ channel running through the middle makes it easy to fasten additional gear to it.

cradle rings

The included cradle rings for the Explore Scientific ED140

Integrated Dew Shield

The integrated dew shield is large and stays secure. It’s quite stiff and tight, which I like. I can be confident that the dew shield will not slowly slip down the tube when the telescope is pointed upward.

Essential Astrophotography Accessories

Recommended Field Flatenner/Reducer

Currently, there is no dedicated field flattener for the ED140 APO. The team at Explore Scientific has assured me that a dedicated flattener/reducer will be available for this telescope soon. I plan to try out my 2″ StarField 0.8X flattener/reducer on this telescope to see if it’s a good fit.

Adding a Guide Scope

Upon opening the locking case, you may notice a lack of finder/guide scope with this package. I feel that most folks looking to upgrade to the ED140 CF will already have an existing guide scope, so it wouldn’t make sense to pay for another one as a part of this package.

Thankfully for me, the ED140 came with a pre-installed base (saddle) for a finder/guide scope. This means I don’t have to look for any additional mounting rings or add any extra hardware to the scope.

I’ve been able to use the Explore Scientific finder scope mount from my ED102 on this telescope. If you don’t already own this specific style of mount, you’ll need to order one. It’s a bit different than a traditional Synta-style saddle that you’ll find on the Orion branded products.

50mm Starfield Guidescope

The 50mm Starfield Guidescope is a great match with the ED140

Inside this mount, I’ve installed a 50mm Starfield guide scope. This is a compact, lightweight and wide field guide scope that pulls in numerous guide stars for autoguiding purposes. Ontario Telescope sells this guide scope as a package with the Altair GPCAM2 camera, making for a very convenient and complete autoguiding combo.

50mm Starfield Guidescope Complete Autoguiding Package

I haven’t talked about the StarField guide scope I’ve been using a lot lately, but I will in the near future. I will say that I’ve got 50 and 60mm versions that both do an excellent job of autoguiding when used with the Altair GPCAM2 mono guide camera.

 About the Ohara FPL-53 Glass

The most impressive feature of this refractor has to be the Ohara FPL-53 extra-low dispersion ED glass used in its triplet optical design. This is a top of line material and considered the best glass ever produced by Ohara.

FPL-53 Glass

The company mentions that the FPL-53 glass used in the Explore Scientific ED140 is very similar in characteristics as Hoya FCD-100. I’ve received numerous questions about the differences between the FCD-100 versions of the Explore Scientific telescopes and the original Hoya extra-low dispersion glass versions.

My ED80 and ED102 both used the original Hoya glass, and making a defined difference in image quality between these telescopes and FPL-53 is difficult. A refractive index comparison is needed to tell the subtle differences in these materials.

The bottom line is, the glass used in the Explore Scientific Triplet series APO’s have always produced incredible astrophotography images, and now they’re better than ever. FPL-53 is perhaps the finest glass you’ll find in a refractor telescope with characteristics closely related to pure fluorite.

The Meade 70mm Quadruplet APO and the William Optics Z61, Z73 and FLT 132 all use FPL-53 as well. This is a true diffraction-limited optical design that virtually eliminates chromatic aberrations and produces high-contrast images. This Explore Scientific telescope also utilizes proprietary EMD enhanced multi-layer coatings on all optical surfaces.

A versatile astrophotography workhorse

The focal length of the ED140 is 910mm. So, a great mid-range magnification at prime focus, perfect for most nebulae and the larger galaxies. My favorite emission nebula targets such as the Omega Nebula and Lagoon Nebula are the perfect size for this focal length.

The lack of a dedicated field flattener/reducer at this time means that I am forced to find a workaround if I want sharp stars to the edge of the field. My crop-sensor (APS-C) sized DSLR and astronomy cameras (ZWO ASI294MC-Pro, Altair Hypercam 183M) have relatively small sensors, so this is less of an issue. Full-frame camera owners looking to utilize the full imaging sensor size will definitely need a solution from Explore Scientific to fully enjoy this telescope.

backyard telescope

Mounting and Autoguiding

The ED140 is about 20 lbs, so a robust equatorial mount such as the iOptron CEM60 is needed to use a refractor of this size for deep sky astrophotography. During my first imaging run, I had tremendous success using the Starfield 50mm guide scope package for autoguiding.

Those looking for a plug-and-play autoguiding solution should certainly give the Starfield / GPCAM2 combo a look. Just remember that you’ll need an Explore Scientific style finder mount to attach it to the base.Deep sky astrophotography telescope

Final Thoughts

My “first light” with the Explore Scientific ED140 was a huge success, and that’s not always the case with a brand new telescope. This speaks to the reliable and painless experience a refractor telescope like this provides to amateur astrophotographers.  The ZWO ASI294MC-Pro turned out to be a great fit with the ED140 – with only the very edges of my image frame showing elongated stars (even without the use of a field flattener).

The broadband RGB image of M13 I captured was a pleasure to process, and clearly showed the difference the added aperture makes when it comes to astrophotography. The combination of longer focal length and extra light-gathering power resulted in my best version of the Hercules globular cluster to date.

Great Globular Cluster in Hercules

The Great Hercules Globular Cluster (M13) using the Explore Scientific ED140 CF 

This image uses 2 Hours and 9 minutes (129 frames) worth of total integrated exposure time using a ZWO ASI294MC-Pro Camera.

On June 15th, I captured the following image of the Trifid Nebula using the 140 under dark skies. For a behind-the-scenes look at the complete setup used for this photo, watch my video from the 2018 Cherry Springs Star Party

The Trifid Nebula

The Trifid Nebula using the Explore Scientific ED140 CF 

This image uses 3 Hours and 3 minutes (61 frames) worth of total integrated exposure time using a ZWO ASI294MC-Pro Camera.

 

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Cocoon Nebula with an 80mm Telescope

|Nebulae|0 Comments

IC 5164 – The Cocoon Nebula

Imaged with an 80mm Refractor

We have had a stretch of clear nights this summer, and I have been taking full advantage! This year I decided to spend some time in the sweet spot of the sky, Cygnus the Swan. This area of the night sky rises high overhead throughout the night, free from the Earths atmosphere.

My first target was IC 5164, The Cocoon Nebula. I have never attempted this object before because I heard it was quite difficult to image, and to be honest, I just didn’t like the look of it!

Cocoon Nebula 80mm

The Cocoon Nebula – Imaged with an 80mm Refractor Telescope

That all changed once I stacked my first night’s worth of images into DeepSkyStacker and saw the beautiful pink nebulosity and dust lanes start to appear. I became obsessed with adding as much time to this deep sky object as possible. I imaged the Cocoon Nebula for 3 consecutive nights, June 30, July 1 and July 2.

Photography Details

Total Exposure Time: 5 Hours (60 x 5 Minute Subs)

Telescope Mount: Skywatcher HEQ-5 Pro Synscan
Camera and Telescope: Canon Xsi (stock) Explore Scientific ED80 Triplet Apo
Guided with PHD Guiding
Stacked in Deep Sky Stacker
Processed in Adobe Photoshop CC

NGC 6960 – The Western Veil Nebula

Western Veil Nebula

NGC 6960 – Western Veil Nebula

Next up is the gorgeous “Witch’s Broom” Nebula, or more specifically, NGC 6960 – The Western Veil Nebula in the constellation Cynus.  I haven’t shot this object since 2012, with lackluster results back then.  This time however,  I photographed it under darker skies, with better guiding and focus.

Photography Details:

Total Exposure Time: 4 Hours, 41 Minutes (61 Frames)
Camera and Telescope: Canon Xsi (stock) – Explore Scientific ED80 Triplet Apo
Telescope Mount: Skywatcher HEQ-5 Pro Synscan
Guided with PHD Guiding
Stacked in Deep Sky Stacker
Processed in Adobe Photoshop CC

Canon Rebel Xsi: Now Modified

Now with a “Naked-Sensor” for better Astrophotography

I have some exciting news about the advancements in my astrophotography!  My next post will talk about my recent modification to my Canon Xsi to remove the IR Cut Filter. Stay tuned for a full post and description of this process!  I’ll give you a hint, I used the How to modify your Canon DSLR for Astrophotography tutorial video.

80mm Refractor Telescope

My astrophotography rig at dawn

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Rosette Nebula – Stock Canon DSLR

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How the Rosette Nebula looks with a Stock DSLR

Will an unmodified Canon DSLR pick up the red nebulosity?

Happy New Year! I was finally graced with some clear skies that showcased the beautiful winter milky way on Monday. The moon was about 19% lit, and didn’t set until about 10:30pm, so about half of data in the photo above was captured with the moon still out. The sky conditions were so fantastic on Monday, it was a shame I had to leave early to get a good night’s sleep for work the next morning.

The Rosette Nebula (Caldwell 49) is a large circular HII region. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula’s matter.

Rosette Nebula Stock

 

Caldwell 49 – The Rosette Nebula
Imaged Monday, February 3, 2014

38 subs, 3.5 Minutes Each totaling 2 Hours 13 Minutes

I used the Explore Scientific 80ED telescope for this photo because the size of this object is quite large. I am quite happy with my end result, although I plan on processing the photo several more times to try and pull out as much detail as possible.

I highly recommend Noel Caboni’s “Astronomy Tools” action set for Photoshop. I found it very helpful when processing this image, and every other image I have taken. For the price of a cheap filter, you can drastically improve your astrophotos. Well worth it!

Complete Astrophoto Details

Telescope: Explore Scientific ED80 with WO Flat III 0.8x FR/FF
Tracking Mount: Skywatcher HEQ5 Pro Synscan
Guiding: Meade DSI Pro II and PHD Guiding
Guide Scope: Orion Mini 50mm
Camera: Canon EOS 450D (Stock)
ISO: 1600
Exposure: 2 hours 13 Minutes (38 x 210s)
Processing Software: Calibration and Stacking in Deep Sky Stacker, Levels/Curves/Enhancements in Photoshop CC
Support Files: 12 darks

 

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