Turning my Esprit 100 refractor telescope into a fast astrograph!

The good folks at Starizona sent me one of their APEX-ED L reducer/flattener to use on my Skywatcher Esprit 100 refractor telescope. It will turn it into a super fast F3.6 astrograph.
#astrophotography #Esprit100 #Starizona #APEX

[@SharpStarAstro]

Great video! Can't wait to see what you get with the reducer/flattener!

[@VisibledarkAstro]

Thanks for tuning in! I'll be posting more videos on the APEX as I get to work with it more. Just need the clouds to go away!

[@mariospenard5125]

Hi Shawn! Sorry to disturb you again. Do you have some more testing with the Apex 0.65L reducer? Thank you!

[@jimwaters304]

For me the APEX-L with the same scope you use and an APS-C camera (ASI2600MC Pro) produced too much vignetting. With careful Flats you can calibrate most of it out but in doing so I lost fine nebulosity detail in M45 and other images. The APEX-L does deliver pinpoint stars with careful backfocus adjustments. For a 1” or 4/3 sensor this would be a good addition. I look forward to your opinion.

[@VisibledarkAstro]

Thanks Jim. So far in my tests things seem pretty good. I think with good flats and DBE in PixInsight the vignetting will be manageable and negligible. Will see how it goes!

[@jasondain8713]

@@VisibledarkAstro I saw the same results as Jim above with my 2600MC Pro. I got some weird rings in my flats that I couldn't calibtrate out and ended up sending mine back.

[@Aerostar509]

Do they make a reducer/flattener model for my stomach?

[@VisibledarkAstro]

You and me both! lol

[@mariospenard5125]

Can’t wait to see your test results. I am using the Esprit 100 with the Apex L for a few months now!

[@VisibledarkAstro]

Super! How do you like it?

[@mariospenard5125]

@@VisibledarkAstro not very good at corners with my APS sensor. Maybe I have to fine tune my back focus distance. I have 58mm at the moment!

[@Steve_The_Ignorant_Astronomer]

Back focus just mucks me up !!!

[@davepastern]

Looking forward to your views - I'm thinking of getting the APEX-S for my Esprit 80.

[@VisibledarkAstro]

I'm impressed with the APEX having done some testing with it. Gotta tweak the spacing a bit still. I was a bit skeptical having heard from some people that had negative experience with it. But my experience so far is good!

[@davepastern]

@@VisibledarkAstro SkyWatcher recommends this themselves. Imaging circle for my Esprit 80 is around 33mm and the diagonal dimensions (longest) for my 1600 mm pro are 22mm, so I wouldn't be expecting any vignetting.

[@astrocapetown4955]

You will love the speed 😀.

[@VisibledarkAstro]

Hope so!

[@TheMje1963]

I used mine on my Esprit 100 when I had one. Worked great with my ASI294. When I upgraded to the Esprit 120 Still worked great. When I got my ASI2600 it seemed to crop the corners. Mine is a 1st Generation APEX. I should ask them if it will work on either my SW 127 or SW 152. Last I heard from them they were in the planning stages of designing one for the full frame sensors such as the ASI6200 and QHY600

[@davepastern]

2600 is a helluva lot larger FOV than the 294...of course it was always going to be problematic.

[@VisibledarkAstro]

Thanks for the info Mark! Ya I want to inquire with them on the larger format APEX. The APEX L I have right now is performing good I think. Just need some tweaking. But accommodating larger sensors would be super.

[@robertw1871]

It looks really tiny, I went with the SW 0.77 for my 120 after seeing too many complaints about the Apex being far too small for APS-C and Fullframe… That speed is very tempting though…

[@rvoykin]

Looks great .65 takes off so much focal Length though

[@VisibledarkAstro]

Yes it does but I've been shooting longer focal length for years now and this changes things up. Will be fun!

[@rvoykin]

@@VisibledarkAstro funny when you start with a redcat all you want is more focal length and when you shoot long you want wider field haha

[@Mistr_A]

Looking forward to the result, pity it's based in the USA and very hard to come by in Australia without sacrificing a kidney after you take into account the exchange rate and import duty.

[@davepastern]

isn't that anything in Australia? We get fucked over big time by greedy taxes, greedy distributors, greedy importers and greedy retailers...all of them should be bloody kicked out of Australia if you ask me.

[@daenu]

You might have to use special narrow band filters made for fast telescopes. Otherwise the filters transmission ratio drops to a very low level which would require much longer exposure times. Also, a filter size of 36mm might be too small. ZWO says on their website that their new 36mm filterwheel works only to f/4.2 for the ASI2600MM. I know you have a QHY camera and filterwheel, but I suspect that it has similar limits.

[@kowalskik.1333]

I also don´t know why he is using a filterwheel on a color camera.. however, up to 4/3 sensor there should be no problems with most filters even on fast scopes. For APS-C indeed one needs at least 36mm filters, they work up to f/4.0. Small vignetting can be eliminated with flats. Distance filter-sensor should be maximum short.

[@VisibledarkAstro]

I'm using the mono QHY268. Hence the filter wheel. :)

[@VisibledarkAstro]

Yes I'm aware of this. I'll just have to see what results I get. I think it will still be ok at F3.6. Negligible anyhow. I'm using 2" filters.

[@derekregan6926]

A reducer alters the light cone,so it shortens the focal length.. you not changed the aperture so the f ratio is still relative to itself fl÷aperture= f ratio.. photons travel at the same speed, so how do they speed up?

[@bronco_fv]

Did you by any chance try to use an Optolong l-eXtreme at f/3.6? Does that work, or do you experience ban shift?

[@VisibledarkAstro]

No not yet. The Esprit 100 is currently sidelined while I am working with the Starfield Optics 8in astrograph. I'm hoping to get back to the Esprit at f3.6 sometime in the future though. For now I'm running F3 with an 8in scope and its a beast!

[@gregmckay666]

"Stair"azona? I'm pretty sure it's pronounced STAR-azona.

[@TheMje1963]

Your close Starizona (Star-Iz-ona)

[@VisibledarkAstro]

ya lol, just can't pronounce it right. I've said it that way for years. Bad habit almost. 😃

[@TheMje1963]

@@VisibledarkAstro LOL, That okay we know who you are talking about, You Canadians don't seem to butcher things as much as the Brit's or Aussi's

[@edwardgill1042]

@@TheMje1963 Almost there. Try Star-i-zon-a, it's a play on Ar-i-zon-a or Air-i-zon-a. From a native of Tucson, which is pronounced Too-saun. 😇 Great channel by the way!

[@TheMje1963]

@@edwardgill1042 The guys at Starizona are awesome. I'm in Phoenix and take the drive to chat with them when ever I get the chance. They know their stuff and are not afraid to part with their knowledge.

[@psuaero100]

Any update on the Apex performance over the past few months?

[@VisibledarkAstro]

I never got the backfocus precise enough. It was very close though. I also was dealing with some sensor tilt which makes it more difficult. I didn't get to finish with the setup as I switched setups.

[@johnnyredfireastroimaging5266]

How did you come up with 58mm? Is it normally 55mm and the 3mm is how the FR is installed?

[@quandilfaitnoir7796]

The back focus changes with focal lenght with this reducer. 500-600mm is 58mm back focus and it drops 1mm every 100mm of added focal lenght. 900mm and up is 55mm of back focus.

[@kowalskik.1333]

@@quandilfaitnoir7796 Its written in their manual: cdn.shopify.com/s/files/1/0327/2569/6648/files/Apex_ED_Instructions.pdf?v=1611096647

[@VisibledarkAstro]

What AstroFab wrote! 😀

[@quandilfaitnoir7796]

Bought one to use with my ES ed 127mm and sold it one month later. All the FOV i gained, i lost because of vigneting. And that was with a 4/3 sensor. Maybe I should of tryed to get better flats but i was too much disaponted. Its supposed to have a 30mm imaging circle. Maybe with a 2.5 or 3 inch focuser this would not have hapenned. For me in Canada, it cost me almost 800$ to get it with the 100$ surprise DHL custom fee. It will probably be a better fit with the esprit 100 tough. I really wish this would have worked, but it was not doiing it for me. I will probably try the .7 reducer Explore Scientific makes sometime around. Hope it works for you Shawn. Here is a link to a preview screen in NINA when i was using the apex: photos.app.goo.gl/nop4m8DscL5q8WfW6

[@VisibledarkAstro]

Thanks for the comment! So far my test results with the APEX are good. The vignetting should calibrate out with good flats and dynamic background extraction in PixInsight. Wasn't as bad as I thought it was going be. I was told 27mm by Starizona.