Unboxing and FIRST LIGHT! ASKAR 200mm F4 Lens - the new RedCat?

[@DavidSomersHarris]

I’ve been waiting for an astrotracer video by one of the top AP youtubers! So happy you were the first to step up!

[@CuivTheLazyGeek]

I've got some older videos on Astrotracer as well, and one more coming up soon too!

[@olegsankin1773]

I have this apo lens. It works with QHY168C. Petfect, round stars without any color fringing, no coma, practically no spherical aberration. My congratulations to the optical designers!

[@derekderek2570]

10:45 🤣 you're so awesome cuiv! Thanks for everything you do in the AP community

[@CuivTheLazyGeek]

Thanks Derek!

I have the Pentax K1 MarkII and have had very good very sharp results with an "old" smc PENTAX-A 1:4 300mm and the Astrotracer. at 90.0 s at f/5.6. If you can find one, second hand, I am sure that you will be thrilled as well. I would recommend that you use a cable release, please.

[@orionm4268]

Astro tracer feature seems to be good for those who like to do wide field night scapes without the bulk need of a tracker. Pretty cool

[@CuivTheLazyGeek]

Exactly - no polar alignment needed either!

[@JeffHorne]

Can’t wait to see what you do with this! I love my 180. 🙂

[@CuivTheLazyGeek]

The clouds are having somewhat of a say on the matter for now :D

[@laurentldoldi840]

Excellent! I have a K3-III and was wondering if the Astrotracer would work with such a lens (ASKAR) not sending the focal length to the camera? Did you entered "200mm" manually into the K1?

[@simonwalsh6804]

Hi Cuiv, great video - love that you have come back strong! On this rare occasion I am going to disagree with you though - I think those star shapes peripherally would annoy me eventually. I am still struggling to find a camera lens that will truly do full frame (even APS-c would be ok). 4/3 is the best I have been able to achieve. Perhaps I need to try harder! Thanks again for everything! Simon

[@CuivTheLazyGeek]

Thanks for the feedback SImon! With this lens, APS-C definitely looks like it would be fine. My guess is that it's either Astrotracer tilting the sensor as it tracks the stars, or distance from lens to sensor (I bought a couple of 0.3mm M48 spacer rings to test this out). Others have gotten great results on full frame: www.cloudynights.com/topic/727293-askar-200mm-f4-astrophotography-lens-scope/#entry10478276 I plan on testing it out properly on a scope when the skies clear!

[@jlecomte0719]

Your French accent is perfect when you say “Pièce de résistance”. You must have watched the movie Ratatouille 😜

[@CuivTheLazyGeek]

Well I did watch Ratatouille (or the silly title they gave to the movie in Japan, literally translates to "Remi's delicious restaurant" - they always to that with Pixar movies), but I am also actually French so that does help :D

[@slim1857]

D'ailleurs bravo pour l'effort de tout faire en Anglais depuis le Japon de surcroît ;) Tes vidéos sont vraiment instructives et je ne m'en lasse pas !

[@billvinson7859]

A great setup. I have the Pentax K-70 with the GPS Module to use the tracker feature. I also have the Canon EOS Ra and the Redcat.

[@CuivTheLazyGeek]

Sounds like a killer set!

[@lunawatanabe5311]

Ah! I remember seeing this lens-- the old version, without the top saddle-- at the Astrophotography showroom in Tokyo the other day! They let me hold it, and my god, was it heavy, but the build quality was just absolutely lovely.

[@CuivTheLazyGeek]

Exactly - heavy but in a way that makes you want to snuggle with it :p

[@lunawatanabe5311]

@@CuivTheLazyGeek "Snuggle" Absolutely; I felt the same way! It's like a kitty!

[@stevel3o7]

Thanks for the review! I have the Redcat 51 and shoot modified Sony a7s and unmodified Sony a7rii. Based on your and others reviews the Askar 200 F4 seems like a strong competitor

[@CuivTheLazyGeek]

It definitely is, but please note that right now I sent it back for checking/repair as it seemed to get bad star shapes fairly quickly in the corners, so there could be unit variability...

[@DrawsACircle]

I have managed to get 50sec exposures with my K-70/GPS and a 200mm f4. Went after M51, it’s a challenge to find it and keep it in the FoV, but what a rewarding experience when you manage to do it. I also use my Pentax Da*300mm, both with the K-70 and my ASI533MC Pro on a mount - it’s a pretty decent lens for astrophotography.

[@CuivTheLazyGeek]

50s exposures sounds very long! I really need to experiment more, away from the city!

[@robertcalise8634]

Hi Cuiv glad to see you posting regularly again. Are you happy with the build and optical quality of the Askar 200 lens I'm anxiously waiting delivery of my Askar FRA 600/5.6 astrograph later this month and hope it performs well Glad your feeling better

[@CuivTheLazyGeek]

For the moment, definitely satisfied with the build quality. As for the optical quality, I need to do more tests to really give a definitive answer. However, as it stands, the optical quality does seem outstanding as far as I can tell!

[@przemekmajewski1]

I totally love the ACL 200, have done a few projects with it ;)

[@CuivTheLazyGeek]

Awesome! Clouds aren't letting me play with it for now though :(

[@Matteo_g-p2j]

Great unboxing and very good looking lens. As you mentioned I am a bit doubtful for the weight. I read 1.8kg which is close to the 2.1 of my petzval AG70/350

[@CuivTheLazyGeek]

Yep, it is indeed heavy. And big for a 200mm lens. There must be a huge amount of glass in there!

[@derekbaker3279]

Thanks for posting this Cuiv! 👍👍 I'm pleased to see that your purchase was an "Askar", not an "Arse-kar". 😁😂 BTW, I'm wondering about the source of the elongated stars in the image you showed. 🤔 I suppose that it depends on how the Pentax camera attempts to compensate for the motion of the stars...does it slowly move the sensor up/down and left/right? If that is how the Pentax system works... and if I understand things correctly...then - in a sense - the sensor is attempting to track the stars like an alt-azimuth mount (assuming the camera is perfectly leveled). In that case, the final image would show some level of field rotation, and the amount of field rotation would be dependent on (a) how far from the celestial equator the camera is aimed, (b) what the focal length of the lens is, and (c) the length of the exposure.🤔 If there is field rotation, I would think that we would see stars that are elongated perpendicular to an imaginary line joining the star to the centre of the frame, and the amount of elongation would be larger as one looks further & further away from the centre of the frame. (i.e. it looks like the stars are rotating around the centre of the frame). However, from what I seen the elongation of the stars all point towards the centre of the frame, which would seem to be more indicative of field curvature, or coma. Finally, if it is indeed optical aberations, not field curvature, I would think that the elongation would be observed if you mounted the lens & camera on one of your equatorial mounts.🤔 Obviously, my understanding is incorrect, so could you explain the star shapes you are getting? Thanks Cuiv! 👍👍

[@CuivTheLazyGeek]

You're absolutely right Derek - I can't quite explain the star shapes. Astrotracer does compensate for field rotation (which would make the stars trail in a different direction), but I'm wondering whether when it is in fact introducing tilt (e.g. tilting the sensor itself) while moving, which could explain those star shapes. Another possibility is that the sensor is slightly too close to the lens - and that would show this kind of issue in the corner. I've ordered some cheap 0.5mm M48 spacing rings for me to test with and without, this time on an equatorial mount and without astrotracer!

[@MrTyroneweaver]

I don't know that much about this stuff but which is better this lens or a Sharpstar 61EDPH II f/5.5 Triplet APO Refractor Telescope

[@captaincook6666]

Hi Cuiv, where do you think this sits compared to the FMA230- I am about to get one or the other- for an AZGTi EQ mode mount. Is the weight significantly more of a problem do you think? Will I really se much between the F/4 & f/4.5 for the worse tracking?

[@OlliesSpace]

Hey Cuiv I've seen this here in Australia so interested how you go with this. I also have a Samyang 135 and old Canon f4 70-200 so very interested to see your shots with this. BTW I love how your opened it like a kid, we are all big kids at heart. It's always Xmas day when you open a box. Have fun with that beast of a lens.

[@CuivTheLazyGeek]

Thanks Ollie! Clouds have since been prominent, but I will make good use of the lens!

[@keithhanssen7413]

I tested the Askar 200 with a 5DMIV and $2000 Canon 70-200 L lens and the Askar won hands down in sharpness, sharpness from corner to corner (the canon lens had a ton of blurring towards the edges) and also the Askar showed zero vignetting on a cloudless daytime sky with both lenses at f/4. The color was surprisingly similar, too. It’s been too smoky for me to test it on my dark skies, but that’ll happen soon.

[@derekbaker3279]

🤔Even the best zoom lenses can be problematic, especially those that are capable of image stabilization. Since the spacing between lens elements (plus lateral position or tilt of some of the lens in IS lenses) can change - and machining tolerances are never perfect - subtle changes in the alignment of the optics can occur, which leads to poorer star images. I would be interested in a comparison between the Askar 200 & the very good Canon 200mm F/2.8 prime lens (which performs well stopped down to F/4). 🤔 I hope your skies will be free of smoke a.s.a.p.! 🤞🙏

[@keithhanssen7413]

@@derekbaker3279 thanks! If the Askar isn’t up to par with me, I’ll be looking for that Canon 200mm prime lens. Another huge difference between the Askar 200 and the Canon 70-200 was the focusing. MUCH easier to focus with the Askar. Move a hair with the Canon lens and the focus went out quickly, but the Askar needs some movement of the focuser before focus goes out.

[@CuivTheLazyGeek]

While I can't use the Canon lens directly with the full frame of the Pentax camera, I do remember it as being very good, but still not perfect at F4 on a M43 sensor. The Canon 300mm f2.8 was the same - I had to stop it down quite a bit for controlling the chromatic aberration.

[@keithhanssen7413]

@@CuivTheLazyGeek I have hopes that this ACL200 will be sufficient for me and all indications point to it being perfectly fine. I’m not super critical, but my limited astro time because of the weather in Montana make my astro time valuable and I’ve spent serious moolah on QHY cameras so I do expect a high level of quality. I’ve pixel-peeped on astrobin and the stars always look good to me all the way to the corners and the stars are nice and round. Nice focusing mechanisms and quality build are readily apparent, so what more can I ask for?

[@ShevillMathers]

1/4”’& 3/8’’ camera thread which at least has been a universal standard across camera history.

[@CuivTheLazyGeek]

Glad some standards stay, and stay consistent! We've pretty much figured out mechanics, but electronics keep evolving...

[@grahamwhite75a]

Hi Cuiv, like you I have done the full journey of starting with a small APO then progressing to larger telescope only to find them too cumbersome and returned to the smaller scopes. I am interested in a small wide field scope like the Aksa ACL200 or the WO RedCat 51. But I am puzzled, I always thought wide angle lenses have very narrow focal ranges compared to long focal length telescope and lenses. I suspect this characteristic also means sensor tilt is more of a problem for wide FOV lenses and telescope. If that is the case why do these types of lenses and telescopes have helical type focusers? I would have thought these instruments would benefit the most from Crayford type focusers? Am I missing the point, are these small compact scopes grab and go scopes best suited to a DSLR or OSC and paired with something like a SkyWatcher Star Adventurer as simply portable mounts that are light to transport but may need a bit more manual intervention to keep in focus?

[@CuivTheLazyGeek]

Yep, the helical focuser is something that I generally dislike - you need a belt to do autofocus, etc. I think it helps with the overall size of the lens, and also makes it more familiar for "normal" photographers. Fast lenses and telescopes are indeed extremely sensitive to sensor tilt regardless of FOV (low FR means higher angle of incidence of the light rays, means a much bigger impact for a small amount of tilt ), but I'm not sure whether a Crayford would actually help with the tilt! For me the biggest drawback is the difficulty to fit an autofocusing system. These lenses are indeed made to work with a Star Adventurer & OSC or the like for very portable setups (although mono is definitely possible as well). But because there's so much glass, the glass itself will change shape with temperature so there will definitely be focus shift - meaning regularly focusing again is a good idea. If focusing manually the helical focuser works fine - otherwise it needs a belt with an autofocuser...

[@marccarrier]

Can you compare a 10 and 20 seconds frame without the Astro feature of the Pentax?

[@CuivTheLazyGeek]

Definitely in the plans! Clouds disagree with the plans :)

[@peterlaubscher3989]

Many thanks for this informative review. I've been reading about this lens on "Cloudy Nights." It looks like a winner! Am currently using a Rokinon t/2.2 and finding it excellent - fully manual. Hope to make the ASKAR my step up to a longer focal length next year. Also interesting to learn more about the Astrotracer. I've wondered about using the Astrotracer in combination with say an EQ mount. Would Astrotracer help smooth out some of the imperfections in a conventional EQ mount, possibly reducing the need for guiding for all except very long sub-exposures? I'd be very interested in your thoughts on this topic. I am so looking forward to seeing the fruit of your work with this ASKAR lens in the coming months. Merry Christmas!

[@derekbaker3279]

Hi Peter. You've posed an Interesting question re: Astrotracer. 👍👍 IMHO, if the sensor is designed to only move to the right (to track the motion of stars from E to W) then I would think that it couldn't compensate for declination drift or a mount that briefly moved faster than the stars. If the sensor is designed to detect the motion of the stars & can move left/right and up/down, then it may be able to do what you suggested. 🤔

[@peterlaubscher3989]

@@derekbaker3279 Many thanks, Derek. Yes, I suspect that it is designed only with East to west Motion in mind. I'm given to trying random combinations of technology. Mind you, astrophotography often forces us to do just that!

[@CuivTheLazyGeek]

Astrotracer is really made to work on its on - it's not made to work with a conventional EQ mount. I mean you could use Astrotracer for a few minutes, then have the EQ mount recenter automatically, but then using Astrotracer makes little sense - the EQ mount will simply be better.

[@peterlaubscher3989]

@@CuivTheLazyGeek Many thanks, Cuiv - that makes sense . Amazing technology at our fingertips!

[@Fredruiz622]

Great video as always! I would like to buy one to match to an ASI533 but when I do the calculations the pixel size comes out to 2.31 arcsec/px a bit to high for my liking, I like to keep it .7 to 2 max. What number do you get with the Pentax camera?

[@CuivTheLazyGeek]

Thank you! Oh I didn't even compute my resolution on the K-1. It's severely undersampled, but it doesn't matter to me - oversampling is bad, but undersampling is not an issue to me (not capturing as much detail as I potentially could in my conditions? I don't care).

[@Fredruiz622]

@@CuivTheLazyGeek , Got it, thanks.

[@marcusa3177]

Where and how much did you get this in Tokyo? I guess someone's no longer getting the Rokinon pocket rocket hahaha (but f2 though XD) when he gets back to Japan XD. That coarse and fine focus mechanism reminds me of what we had in microscopes years ago in high school bio lab. And I love the focus locks. That said - lemme get this straight: this can accommodate 2in filters regardless of the camera behind it? Because if yes, I guess I can now pull off a double-headed setup on the iOptron SkyGuider Pro, one on each end of the DEC bracket. HMMMMM. Imagine two similar OTAs (same FL and cameras) pointed at Orion, with M42 in one corner and the Horsehead in the opposite corner. One camera is broadband, the other with at least a dual narrowband filter. That'd be a blast to process hahaha PS - if the Pentax has focus peaking, that can be used as a poor man's Bathinov mask. Turn on focus peaking, zoom in a small star with the screen magnifier, and focus until the stars are at their smallest.

[@CuivTheLazyGeek]

I got it from Kyoei Tokyo the online shop - they ship very quickly. And yes the focus locks are great! So yes it can accommodate 2 inch filters regardless of the camera, but I expect those filters to slightly increase the backfocus distance. So having a couple of 0.3mm or 0.5mm M48 spacer rings could be a good idea! And yes, that double headed beast you're mentioning could indeed be a lot of fun! :) I found that in general focus peaking interferes with star fine focus - it gets activated very close to best focus, and not at best focus, and then makes it difficult to see the best focus!

[@marcusa3177]

@@CuivTheLazyGeek thanks for the store name! Putting a note in Google Maps for my future self who is taking a vacation in Japan; not sure if they deliver to where I am now (outside of Japan) but I'm sure to drop by the store once the borders open. My wallet is already scared hahahahaha

[@davidfrederick8198]

Sharpcap? Redcat? Sharpstar? so much to remember. :)

[@CuivTheLazyGeek]

Ha! Yes indeed! I get confused when I speak about it all the time!

[@davidfrederick8198]

@@CuivTheLazyGeek Still a great unboxing video, hope you can do a follow up soon.

[@keivanhamidi]

Pièce de résistance😂😂 ça m'a tué😂 mais very nice lense!

[@CuivTheLazyGeek]

Merci :D

[@EODHammer]

Let us know what you think once you get some time with it. I have a Redcat that I don't use much but I really should. I have that same samyang too. Love that lens!

[@CuivTheLazyGeek]

I definitely will! Clouds have their say about it though...

[@EODHammer]

@@CuivTheLazyGeek I’m in north Florida. It’s so humid here and the mosquitoes and gnats are so bad I don’t even bother trying to image in the summer. Really sucks. Seeing is so bad I can’t even guide. Looking forward to “Winter”.

[@TR6Telos]

I was as excited as you , new stuff mmmmmm

[@arjanvanloo2177]

Can I ask where you got the pentax K-1 astro-modified?

[@CuivTheLazyGeek]

Yes! I actually sold the original one, and bought an astromodded version on Yahoo Auctions. It was modded by a now defunct Japanese company called Starshop... There's still one astromodded Pentax (K-70) on sale there.

[@arjanvanloo2177]

@@CuivTheLazyGeek Thanks a lot! Too bad Starshop went out of business. I'll keep my eye on yahoo auctions.

[@MrExo_3D]

I enjoy your enthusiasm

[@CuivTheLazyGeek]

Thank you :-)

[@davejenkins8524]

the sensor moves? or is it using a ROI thing...?

[@CuivTheLazyGeek]

The sensor itself moves! Using the in-camera 5 axis shake compensation! Which is impressive for a full frame sensor...

[@michael.a.covington]

I have that lens and am delighted with it.

[@CuivTheLazyGeek]

I'm looking forward to using it more and more!

[@astroattorney]

After a lot of reading, trial & error, I dicovered that my Astrotracer performs best with a

[@astroattorney]

Note: I have a Pentax K-1 Mark ii

[@astroattorney]

Aaaagh, Askar FMA 180mm

[@CuivTheLazyGeek]

Astrotracer is really cool - it does seem to depend a lot on the initial calibration. Two nights in a row on the same area of sky I noticed vey different star trailing at 200mm!

[@arjanvanloo2177]

Astrotracer will be limited to shorter exposures with longer lenses, and getting a good calibration can always be tricky (and is more essential for longer glass), but it is possible to get good results with longer lenses. You can see examples of people having used it up to 400mm on APSC (so 600mm full-frame equivalent) in the astrophotography group on the pentax forums

[@ferenc-x7p]

How coincidental, but I was imaging with my Pentax K70 just last night, although I didn't use the astrotracer - which is an extra gadget for the K70 and I have it , but I have mixed results using it. Sometimes it seem to work as it's advertised, other times it acts like it's not even there, no matter how carefully I calibrate the GPS sensor. I was told on the Pentax forums , please try it out away from civilization, in the cities it gets too much magnetic interference that can throw off the gps. On the other hand, the camera produces very clean, noise free and sharp images, and as unmodified it seem to allow more H-alpha through than Canon cameras.

[@CuivTheLazyGeek]

Yes, testing it on the riverside gave me much better results in terms of calibration than on my balcony. It's a very interesting beast!

[@licho52]

With this item I am worried about two (related) things: one is that Askar/Sharpstar has not proven that it can correct colors on OSC with its scopes - they don't use FPL53 and it really makes them iffy with broadband (and by iffy I mean terrible CA). Decent for mono work. The other related issue is that selling Redcat is easy and you recover your investment while Sharpcap and Askar have poor resale. Redcat is simply a proven product.

[@CuivTheLazyGeek]

The TS-Optics branded versions of sharpstar scopes definitely uses FPL53, but not sure about Sharpstar (or Radian Raptor for that matter) and on my Sharpstar 61EDPH II I haven't seen any much CA if any (both broadband and dual-band narrowband, which also shows CA pretty well - at least it did with my Canon 300mm f2.8 lens). As for the Askar lens, on my broadband and duoband narrowband test pics I don't see any CA at this stage. I have however heard of others experiencing CA with the 61EDPH II. As for resale value, not sure about the US, but the samples in Japan seem to hold up their value well!

[@thefourgrapples2810]

I'm going out on a limb, and say that you really like that lens.

[@CuivTheLazyGeek]

Oooh I thought I was being subtle about my emotions here :D

[@anthonywarwick6090]

Just bought mine from AliExpress

[@sugardove6075]

USA seller?

[@CuivTheLazyGeek]

Agena Astro seems to carry it! But currently out of stock

[@PMP5240-e3i]

advantages over the RedCat are?

[@washy934]

Every redcat has odd star shapes (some kind of tiny diffraction), all have coma and most have tilt - and the tilt adjuster (in my case) is horrendous to adjust because the camera is too close to the adjustment screws so I have to remove it and refit it every adjustment. The Askar has none of these issues and produces a flat field on a full frame sensor.

[@jesuspineiro1622]

faster f/ratio, f/4 vs f/4.9

[@pluggednickels]

@@washy934if this was a real issue with all redcats you would see it being mentioned everywhere in the forums. You mentioning it is the first I have ever heard of it My redcat doesnt have any of these issues you mention with odd shaped stars mine is sharp to the corners all corners even when using a full frame sensor. and no odd shaped stars I’m sure this new lens will be a hit but the redcat has great track record of it own already So if there was issues with the redcat like you say it would be well know by now

[@washy934]

@@pluggednickels You mean apart from the ENORMOUS thread on cloudy nights and fairly gigantic thread on SGL about poorly performing redcats, I had one, sent it back, received a 2nd independently tested and adjusted with an optical bench report, and it's the same as the first. The FOV hides many evils, but for the price point and the marketing it should be perfect - and it's not, its nowhere near as good as a samyang 135mm f2, nor an Askar 200mm f4.

[@PMP5240-e3i]

@@jesuspineiro1622 but 50mm less

[@beatsntoons]

as a 50/50 terrestrial vs astro photographer...terrestrial 'togs call that dovetail a lens foot :)

[@CuivTheLazyGeek]

Hehehe thank you!

[@komr323]

still miss your real KZbin videos. Others are advertisement we know

[@msacco]

Damn boi. You should change your youtube channel name. Sounds to me more like "Cuiv, the on fire geek".

[@CuivTheLazyGeek]

Hehehe, thank you!

[@gregb5149]

I can't believe you have a Pentax. What a handicap. No wonder why you dive deep into your investigations. You need to with Pentax - lol. I have a K-5 which is great but I can only control it with Kstars. What did you use? (I gave up and bought an astrocam.)

[@DrawsACircle]

I would say the Pentax cameras have a huge advantage over other cameras if you want to do lightweight astrophotography - that’s with a tripod and an intervalometer.

[@CuivTheLazyGeek]

DrawsACircle said it: I wanted to be able to do AP with no tracker, no mount, no PA, just a tripod and camera. That's my use-case! Of course, for computer control, Canon, Nikon, etc. are better. But I already have my cooled astrocameras for that!

[@woody5109]

Red Cat is more affordable 🤓