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Help flattening a ES 80mm carbon fiber

astrophotography refractor equipment
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#1 najarfermin

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Posted 07 September 2019 - 08:34 PM

Hello everyone. I'm looking for some one who has this kind of setup. I'm having troubles trying to flatten the scope, I have distortion in the corners.

Some friends told me that maybe I need 1 mm spacer for the back focus. Do you know where I can get them ? Some advice ?

My setup:

- Explore Scientific 80mm triplet Apo

- Canon T5i/T7i/t3i

- Explore Scientific 2" Field Flattener - FFEDAPO-01 (55 mm backfocus )

Thank you for help

 

 

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#2 droe

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Posted 07 September 2019 - 09:50 PM

I have found that the Orion reducers works well. I did a comparison in this post that you may find helpful.

 

 https://www.cloudyni...or-es-80mm-apo/

 


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#3 najarfermin

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Posted 11 September 2019 - 12:27 PM

Thanks !!



#4 FlankerOneTwo

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Posted 12 September 2019 - 08:42 AM

Just FYI, there are numerous reports of corner distortion issues with some of the ES flatteners that were not curable with tilt / spacing adjustment. I have two friends with the ES ED80 (which is a fine scope) that spun their wheels for weeks trying to fix the corners with the ES flattener. Both worked fine with my TSFLAT2 and with the Orion flattener.


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#5 Baskevo

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Posted 28 October 2019 - 03:13 AM

Just FYI, there are numerous reports of corner distortion issues with some of the ES flatteners that were not curable with tilt / spacing adjustment. I have two friends with the ES ED80 (which is a fine scope) that spun their wheels for weeks trying to fix the corners with the ES flattener. Both worked fine with my TSFLAT2 and with the Orion flattener.

 

Wow wish I saw this a month ago tongue2.gif I've been pulling my hair out trying to find answers for why my Field Flattener isn't flattening... I originally had a defective one that felt like a cheap knock-off version of the replacement I received after returning it, and the stars at least didn't look over blown and uncollimated, but I still couldn't get the field to flatten. I've the maximum amount of spacing I can possibly add, and there is no difference in my images. I just received my Orion Field Flattener... I'll let you know how it goes



#6 Baskevo

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Posted 28 October 2019 - 03:14 AM

Hello everyone. I'm looking for some one who has this kind of setup. I'm having troubles trying to flatten the scope, I have distortion in the corners.

Some friends told me that maybe I need 1 mm spacer for the back focus. Do you know where I can get them ? Some advice ?

My setup:

- Explore Scientific 80mm triplet Apo

- Canon T5i/T7i/t3i

- Explore Scientific 2" Field Flattener - FFEDAPO-01 (55 mm backfocus )

Thank you for help

So did you end up figuring this out najarfermin?



#7 Baskevo

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Posted 29 October 2019 - 02:36 AM

Sorry for spamming this post, but I wanted to share this...

 

This was 20mm of spacing added to the Field Flattener:

 

https://photos.app.g...CegDu8KhscbtBb6

 

It's still not perfect, but WAY better!


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#8 najarfermin

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Posted 22 November 2019 - 09:38 PM

Not spamming at all ! Thanks for sharing



#9 moonrider

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Posted 22 November 2019 - 11:30 PM

I guess I'm one of the lucky ones that got a good ES flattener. My only problem was getting the back focus dialed in. My ES 80 took 2, 2" focuser extensions and the required 50 to 55mm of spacers.



#10 SeattleScott

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Posted 23 November 2019 - 01:04 AM

Hello everyone. I'm looking for some one who has this kind of setup. I'm having troubles trying to flatten the scope,

An 18-wheeler should do the trick.

Scott
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#11 thedudeabidez88

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Posted 16 February 2020 - 05:00 PM

Sorry for spamming this post, but I wanted to share this...

This was 20mm of spacing added to the Field Flattener:

https://photos.app.g...CegDu8KhscbtBb6

It's still not perfect, but WAY better!



I've been having a hell of a time trying to get my ES 2" 55mm flattener working on my ES ED80 APO CF as well. Can't get my stars flattened no matter what I do. I've even collimated the focuser and lens cell. Just to be clear, is this 20mm beyond the 55mm requirement or just 20mm?

Edited by thedudeabidez88, 16 February 2020 - 05:01 PM.


#12 canyonblue737

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Posted 12 July 2020 - 11:32 AM

I know it's an old thread but I want to make sure the reports keep coming... I was unable to get anything close to a flat field with my ES ED80 FCD100 and the ES Field Flattener (55mm model). I tried back focus distances from 45mm to 80mm! (including 0.5 mm increments from 52-58mm) and never got anything even close to acceptable... the image showed 60% of the entire field had significant curvature and the outer 25% had such severe distortion the the stars smeared like an inverse coma. The "best" back focus (still horrible) for me ended being somewhere between 75-80mm despite having a published spec of 55mm. After 5 weeks of trying on clear nights to resolve the issue I gave up and ordered a Hotech SCA FF and instantly had way better images. Ideal back focus proved to be 55mm with the Hotech, just as advertised, and leaves me with mild distortion only in the outer 5% of the image, slightly worse on my left side (maybe 10%) but that I diagnosed as sensor tilt on my camera that I'll have to try and resolve with a tilt plate. I'm pretty new and I don't know how "perfect" I should expect a $1300 scope and $200 field corrector to be (should I truly have a perfect flat field corner to corner?) but I now know at least I have a very nice image cropping a very small amount... the ES FF is a mess for their own ES ED80 scopes and I would avoid them.


Edited by canyonblue737, 12 July 2020 - 11:33 AM.


#13 Baskevo

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Posted 14 July 2020 - 12:07 AM

I know it's an old thread but I want to make sure the reports keep coming... I was unable to get anything close to a flat field with my ES ED80 FCD100 and the ES Field Flattener (55mm model). I tried back focus distances from 45mm to 80mm! (including 0.5 mm increments from 52-58mm) and never got anything even close to acceptable... the image showed 60% of the entire field had significant curvature and the outer 25% had such severe distortion the the stars smeared like an inverse coma. The "best" back focus (still horrible) for me ended being somewhere between 75-80mm despite having a published spec of 55mm. After 5 weeks of trying on clear nights to resolve the issue I gave up and ordered a Hotech SCA FF and instantly had way better images. Ideal back focus proved to be 55mm with the Hotech, just as advertised, and leaves me with mild distortion only in the outer 5% of the image, slightly worse on my left side (maybe 10%) but that I diagnosed as sensor tilt on my camera that I'll have to try and resolve with a tilt plate. I'm pretty new and I don't know how "perfect" I should expect a $1300 scope and $200 field corrector to be (should I truly have a perfect flat field corner to corner?) but I now know at least I have a very nice image cropping a very small amount... the ES FF is a mess for their own ES ED80 scopes and I would avoid them.

I spent literal months in the exact same position as you, same scope and everything. and I ended with the Hotech 2" SCA FF, with about 80mm of spacing (maybe more, I don't really remember, been a while since I measured). I now have a visibly perfect flat field (other than a little tilt as well, which honestly I don't worry about because it is hard to notice after stacking, cropping, and processing, unless you are looking for it). It is one of the hardest and most annoying things I've ever done... Keep trying it sounds like you are almost there!




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