SCT Corrector Reducer with a Skymax 127 Maksutov Telescope

[@KevinMurphy0403]

Brilliant experiment, thank you for making this video. The Mak is built to be used at its native focal length, this is its strength. People purchase these niche instruments for views of objects that require the F12 or even F15 focal lengths that they offer . I have a Sky Watcher Mak127 (that I bought for 120€ !!!) and its an amazing little telescope (better than my Explore Scientific ED 102 on the moon and planets!), the views are so sharp. I wont be buying an F6.3 reducer anytime soon after watching this!. Cheers Graham, keep up the great work.

[@TTProgressive]

Genial el video. Este tipo de experimentos me gustaría encontrarlos mas a menudo en internet. Muchas gracias y te animo a hacer mas vídeos como este.

[@paulmckeown5672]

Being a MAK 127 owner that was a very useful experiment, thanks for doing it!

[@JenhamsAstro]

Thanks Paul, I was a bit surprised by the issues and am half expecting others to say theirs work fine! My unit is great in its intended use, but not good otherwise.

[@ITProjectManagerMan]

Hi Graham, Just wanted to say that I really enjoy your video’s and find them very useful. I particularly enjoyed your video flocking the C90’s center baffle. I took it a step further by flocking both the tube and the baffle, plus added a dew/light shield. Solved all my internal reflection issues and turned the my Orion 90mm Mak into a champ performer. Keep these video’s coming.

[@JenhamsAstro]

Thanks Jeff I appreciate it. I’m hoping to get back to making new videos soon.

[@Astroturf100]

Hi Graham love this video. I think I have found a better reducer that would work great for the 127mak. This item is just a reducer and does not flatten or correct the field and thus would not hurt the maks already corrected field. Its the Antares F/6.3 focal reducer for F/10 SCT, visual or imaging - Part Number: SCTFR made in Canada and it states in their product description that this item only reduces ONLY. I have heard people of forums trying this and saying they are getting good results with the maks. It might be worth a try; oh and the reducer is not very costly as compared to the Celestron reducer too and apparently just as good in its quality!

[@JenhamsAstro]

Thanks for the positive feedback and the suggestion. I've heard of the Antares reducer and I'll try the unit if I can get hold of one. It's probably not a big suprise that a reducer-only solution will give better results, but I thought I'd try the SCT unit as I already had it, and I always like to try out stuff like this in the name of experimentation!

[@Astroturf100]

@@JenhamsAstro Yes the Antares reducer would be interesting to try. As far as the weird flaring or arc effect in the Mak I get the same thing in my Sky-watcher 127mm mak too when I do visual and bright objects are just outside of my field of view and disappear when they get inside the FOV its so weird. Just a thought is your Mak flocked in the rear baffle tube? Do you get the same flaring effect as I do doing visual? The rear baffle is quite reflective and just wondering if this could be causing the strange arc/flaring effect or maybe the secondary baffle? Food for thought anyway.

[@JenhamsAstro]

@@Astroturf100 I looked at the baffle and the primary one looks fine on mine ie matt. The secondary baffle is a bit shiny though and may be the issue. I’d have to open the tube to flock it but will try this at some point. It makes sense that the reducer is bringing some off axis rays into the field of view. But then I’d expect other users of reducers or reducer correctors to see the issue? Worth a look though for sure. If I try it and it works I’ll let you know. Graham

[@JenhamsAstro]

Forgot to say I haven’t noticed the effect doing visual but will now study more closely. Thanks for the input.

[@Astroturf100]

@@JenhamsAstro Yes thanks. I did have a matt black and ribbed rear baffle tube in my Mak also, it was still bright during day testing; but, I flocked it anyway and I can tell on the Moon that it still helped and especially for day viewing. But I haven't tried very bright stars or planets yet so not sure on that one. Also, I commenter mentioned that his Evolution 8 with a reduced/flattener gave him those flares too and without the reducer they were gone. Puzzling for sure. Further, just to note the rear baffle would be super easy to flock instead of having to do the baffle for the secondary, would be super easy to check and verify. Next time I get a chance I will try my Mak on a bright star now that I have the rear baffle flocked. Eager to see what happens!

[@deep_space_dave]

I collimated my C90 Mak so I can play around with it and I tried it with the Celestron RC6.3 and yep the middle is great but weird stuff start to happen at the edges. Too bad as the C90 is a excellent little scope but limited to planetary and lunar due to it's high F ratio. Thanks for the video and Clear Skies!

[@kennethharpster3403]

I wanted to let you and the those that are interested know, the Antares f/6.3 focal reducer for SCT’s does no correction and works well with my 127 SLT for visual and imaging.

[@JenhamsAstro]

Thanks Kenneth, a recommendation from a fellow astro is always helpful.

[@KZgun4hire]

You probably should use a focal reducer made for visual use. Like those single lens reducers that screw into the back of eye pieces. Not sure how you would get that into the optical train!

[@mycarolinaskies]

I believe I can shed light on the cause of the light artifacts. The correcting element, like any correcting element, is made in respect to the curvature of the system it is designed to correct. These SCT corrector reducers are designed to correct the F/10 system outer quadrants whereas your 127 is a slower less curved field and any over correction becomes like a funhouse mirror giving an odd artifact on brighter stars in the field.

[@JenhamsAstro]

Hello, I’m hoping to do some further testing to see whether a baffle reflection could be an alternative cause. If not I’ll be left with the correcting theory.

[@gunnarjensen5910]

Zwo533 + 0.63 might work on the Mak127 ?

[@odditythreeD]

Just thought I'd pop in to say I don't get these artefacts on the 150mm skymax with an slr or through visual if anyone's thinking of getting this reducer (celestron one), might be because of the size difference?

[@MountainFisher]

My 127mm Celestron Mak _IS_ the Sky Watcher 127 Mac, both made by Synta.

[@dragosniculescu6877]

I discovered your posts just today. First your second experiment, when you tried to block any reflections, now, this post. Examining carefully those pictures first I can say that is an over-correction, when you're using the corrector on Mak. And is manifested not only in those arks, but in a sensible coma at the edge of field, both right and left. But also, I have seen some artefacts when you put the corrector on the C6. I am not sure if is a small vertical movement of the mount, ( or polar alignment ?) or the lenses in the corrector are a little off, but there are some elongated stars in the vertical direction, both on the right and on the left edge of the image. And, strangely, some very small rays that can be seen on the bright stars, longer to the right. But this could be from collimation.

[@JenhamsAstro]

That’s interesting. It is possible that the C5 was slightly out of collimation - I’ve found that Bob’s Knobs allow a quick adjustment but make the need for one more frequent on that scope for some reason. The mount may also have been disturbed in alignment slightly vs the 127. When I started the test with the 127 I hadn’t expected to see the issue, so I ended up switching the C5 in and out as I tried all combinations of scope and reducer, and a slight nudge of the mount could have happened.

[@Khyryk]

Those loops near bright stars look exactly like what happens with a C90 without flocking the baffle tube.

[@JenhamsAstro]

Hi, good suggestion. I looked at my 127 and the primary baffle tube is already nicely matt, so I doubt if that's the culprit. However there is a more reflective surface on the secondary baffle which might not help. I'll need to dissassemble the OTA to darken this. It's worth a try.

[@Khyryk]

@@JenhamsAstro I'd also try varying the backfocus in the range of 85 to 105mm and observing the effect on the stars in the center. In principle, the stars should be just as good as they are with the C5 because there's no correction happening like it may be happening outside of the center. I suspect you'll give up a bit of reduction, but improve on vignetting and sharpness.

[@AntPDC]

Funny, I thought it was your wonderful self who demonstrated the benefits of stuffing a rolled-up piece of matte black paper up the (infamously un-flocked) narrow secondary baffle of the Synta-sourced Mak-Cass 127 etc scopes from the rear-end. Sounds a bit painful though... .Thank you for the demo.

[@JenhamsAstro]

My previous video was flocking the shiny primary baffle on a C90. My 127’s primary baffle is already nicely matt. I wasn’t aware of a secondary issue until it was suggested in a comment. In bright light I can see a reflection from part of the secondary baffle, so I plan to experiment to see if the reducer/corrector is “allowing” reflected light from bright stars near the edge of field to cause the artefacts I photographed. It is plausible. Obviously I’ll have to open the tube to try it but will report back the results. Clear skies.

[@AntPDC]

@@JenhamsAstro Thank you Graham, but I can't find the video you mention with respect to the C90. I'd love a link to it, at your convenience. Best wishes.

[@JenhamsAstro]

@@AntPDC It's this one from a while back. kzbin.info/www/bejne/fIGpi5Wnl8-VhpI

[@oninoyakamo]

Thanks Graham. If you find a pure Reducer that is compatible with Maks, please let us know. It would be great to be able to back off my f/15 Mak a little

[@JenhamsAstro]

Well I thought it was worth a try! One suggestion already in the comments for a reducer option. I hope you find a solution. Clear skies to you either way. Graham

[@Philjim]

I got those same the exact same artefacts on on my Evolution 8 when using the reducer. As far as I could find out, this might be some type of internal reflection. I'm not sure why it only appeared when I used the reducer though. Love the videos! 👍

[@JenhamsAstro]

Thanks! That's very interesting and does cast some doubt on my "over-correction" theory with the Mak. I had a look at my reducer to see if there were any obvious shiny spots, but it looks OK. My Evo 8's innards also look nicely matt. More investigation required.

[@SV_Paciencia]

Same here with a Meade 6inch SCT ACF. I remove the corrector lens of the focal reducer but artefacts still there. Thinking the same of internal reflexion

[@user-pi5xu7qs7n]

I get the same arch's in my 127mm even after flocking and with the CCDT67 reducer. The CCDT67 was not designed for a moving mirror system and the best I could do was an F/9.

[@JenhamsAstro]

That’s interesting thanks. Have you flocked the secondary baffle or just the primary? I’m favouring the secondary as a possible cause, as mine is a little shiny.

[@user-pi5xu7qs7n]

@@JenhamsAstro Just saw this. I only flocked the primary. The baffle was small so I decided to not go that route. Did you ever flock the baffle?

[@JenhamsAstro]

@@user-pi5xu7qs7n Yes, there’s a follow up video where I tried that. Work in Progress! Clear skies, Graham

[@BennyKleykens]

Was wondering just about this so big 👍👍👍

[@Astronurd]

The reducer is only suitable for the 150 & 180 by the way.

[@cliveroberts415]

What a shame I hoped the results would be better but thanks for trying. The 127 is still a fantastic lunar and planetary scope.

[@JenhamsAstro]

Agreed, I love my 127, it's in a real sweet spot in my opinion. When I was making the video it provided a lovely clean split of the trapezium which was fantastic to see (at f/12!). The comments I'm getting are very helpful, from checking for internal reflections to trying a reducer-only solution (another purchase!) so I haven't given up on the project yet. Clear skies to you.

[@RaduChelariu]

I can report no such artefacts when using the AP 0.67 Reducer (not corrector) with the 127 Mak. You can get the same reducer from either Teleskop Service or Tecnosky for not a lot of money.

[@JenhamsAstro]

Thanks. I wanted to try my “on the shelf” SCT unit but it’s good to know that the AP Reducer does the job. Clear skies. Graham

[@cyc996863]

i have a mak 127 + x0.63 but the pictures i took are great. took flat frames though.

[@JenhamsAstro]

OK thanks, good to know. I’ll continue my investigation into the issues with my setup when the nights are longer. Clear skies.

[@astroshlibber9654]

That's a strange distortion, is there any way of using that particular Reducer on a refractor to see if it happens there as well, just to check if its an artefact of the mak or simply long FL

[@JenhamsAstro]

Yes, it is strange. I currently only have a f/7 APO refractor so I'm not sure it's a good scope for a test. No issue in my SCT as noted in the video though. Will do some more investigations and advise if I conclude on the culprit.

What happened to your Mak 150? Don't you use it anymore? Does 127 fit better to your needs?

[@JenhamsAstro]

I’ve sold the 150 as I prefer the size of the 127 for my lighter mount. The aperture works well for me with the brighter planets which are my most common targets.

[@AmatureAstronomer]

I recently purchased a Celestron Nexstar 6se optical tube, x0.63 reducer/corrector and a HyperStar 6 v4 to use with my ZWO asi294cc on my my Sky-Watcher AZ GTi mount when running SharpCap 4.1. I noticed that I get those strange arcs when I look at the screen as I move the optical tube around, with or without the reducer. They have not shown up on photos so far. Any one have any idea what causes this???

[@JenhamsAstro]

Not definitively but your observation suggests an unwanted reflection somewhere and not the reducer per see. I haven’t looked further into it as yet.

[@dschenk952]

Hi do you recall the gear you used to replace the rubber knob on the focuser?

[@JenhamsAstro]

Hi Don, on eBay I bought a 40 tooth GT2 timing pulley with a 12mm bore. Then for the motor end it’s a 20 tooth with 6.35mm bore. Both 6mm wide, for a 6mm belt.

[@dschenk952]

@@JenhamsAstro Thank you.

[@peterwoolliams1283]

Any experience with popping a diagonal and eyepiece on the back? Do we get faster and this wider fields (thought the focus tube is t too wide so it might vignette)?!?!

[@JenhamsAstro]

I did some visual observation when making the video. The field was wider for sure and the vignetting wasn't noticeable to my eye, even though it obviously exists. As for faster, I went down a forum rabbit hole on the subject of whether f ratio actually effects imaging and exposure times. Some strong views were expressed so I'll steer clear of drawing a conclusion on that one!

[@spaceandsky1829]

what happen to you celestron evo 8 sct

[@JenhamsAstro]

I like the Evo 8 a lot. I’ve got used to the alignment process now and have been pleased with the views. It only has features you need. The reducer/corrector works well as mine is the standard Evo rather than the Edge model.

[@spaceandsky1829]

@@JenhamsAstro had the edge on alt az sent it back too much hassle and weight not a massive difference happy with evo 8 just been too cold to use recently lol

[@spaceandsky1829]

kzbin.info/www/bejne/a6O4fHmgfdqiac0

[@spaceandsky1829]

I recommend giving this a watch shows what is possible with alt az on sct 8 using live stacking 👌

[@PafMedic]

Hi Jenham,Always Love When You Make A Video,Dang..Can I Have Your Blue Sky.I Havent Seen It Since Before Christmas,and My Poor Evostar80ed,Has Never Seen A Star,But Want To Say To All The Flat Earthers…You People Owe Me $400,For A Flattener For The Evostar😂😂Nice Shots With The C-5,and The 127,I Like The 127 Better W/O The Reducer As Well,Enjoyed The Video,Thank You and Clear Skies🙏🏻❤️🔭🌏✨

[@JenhamsAstro]

Thanks! Yes the vagaries of the UK weather are very familar to me. I have lost count of how many times the weather app says it will be clear, I put the scope out to cool at dusk and then go out later to find 100% cloud. Eventually your 80ed will have its moment. Until then we must be stoic!

[@PafMedic]

@@JenhamsAstro Yeah,But Grrrrrr When You See It Clear All Day,Then An Hour Before Sunset☄️☄️☄️It All Goes To Crap😂😂Our Skies Have Never Been Like This.Our World Is Changing😥

[@tomcocchiaro3997]

Hi Graham, I was actually watching a similar video from Garnett Leary trying to use the same Celestron reducer corrector on an Orion Apex 127mm mak. Instead of the stock Celestron T-Adapter he used an Astromania adapter which appeared to be shorter than the Celestron T-adapter. He didn't include any images with stars but I would have thought he would have mentioned any issues with night images. He only illustrated a daytime image of a water tower. kzbin.info/www/bejne/bJeZh6yeaZmBn5o

[@JenhamsAstro]

Hi Tom, I’ve seen Garnett’s video, in fact it gave me the idea to try a nighttime test. I’m hoping to do some more investigation to find the root cause, and I’ll add your observation to the list of things to experiment with. Only having a sample of one means I can’t rule out having a duff component in my setup, but then I haven’t had any issues with my 127; it’s a great scope in my opinion. I’ll make a follow up if i can identify the culprit. Clear skies, Graham

[@tomcocchiaro3997]

Hi Graham, I just saw these videos, and have an Apex 127mm Mak, I just received the Astromania adapter and am waiting for the ScopeStuff SMSA thread adapter from Garnett's video. Will let you know what I find. I actually have an Orion 180mm mak and hope I can make this solution work with both. I have to admit I have an embarrassment of riches in "Cat" scopes. Also have a Celestron 6, 9.25, and HD11--the last two with dedicated reducers.

[@JenhamsAstro]

@@tomcocchiaro3997 I don’t think you can have too many scopes!

[@astromatz]

Thanks for the video! I am interested in this idea. Can you please post a link to the adapter which is needed to attach SCT equipment to the MAK? Thanks 🙏

[@ChristianSegonne]

merci et bravo et comme dit: @KevinMurphy0403 "Je n'achèterai pas de réducteur F6.3 de sitôt après avoir regardé ça": moi non plus! PS: j'ais passe commande du 127 ce dimanche (j'ais déjà le 150) mais je voulais un Mak plus léger pour ma Star Ad. Gti Wifi... lorsque je sors en mobil-home...

[@makemystronger..freemegapi6800]

Its a good quality focal reduced for 127?

[@JenhamsAstro]

As per the videos I’ve had a few issues which may in part be due to the use of an SCT reducer/corrector with a Mak. Others in the comments have suggested alternative reducers.