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AT80ED with a ASI533MC - do I need a field flattener

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#1 Mitrovarr

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Posted 13 April 2021 - 10:37 AM

I just ordered an ASI533MC-P for much better EAA and trying out some more serious imaging. For the more serious imaging, am I going to need a field flattener? And if so, which one should I use?

The AT80ED doesn't have a dedicated one as far as I can tell.
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#2 charlieb123

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Posted 13 April 2021 - 10:46 AM

Hotech SCA-FFT58 is a good quality FF for the AT80ED. 
works great on mine. 


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#3 Forward Scatter

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Posted 13 April 2021 - 11:38 AM

I have this one for my 72ED, which I got from Astronomics: https://www.astronom...refractors.html. There also is the 0.8X Reducer/FF that works very well for squeezing out a wider FOV which is nice for the big nebs, but is backordered.

 

There was some peripheral star coma on my 533, starting around 1/4 the frame from the edges. Not too bad, but then again we are perfectionists. This FF took care of it nicely and now the stars are really nice & round. 

 

Cheers, 

J


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#4 Stelios

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Posted 13 April 2021 - 02:03 PM

Hotech SCA-FFT58 is a good quality FF for the AT80ED. 
works great on mine. 

+1 for the Hotech. You will almost certainly need it, but you can determine it easily yourself--try without it and look at the corner stars. 



#5 Mitrovarr

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Posted 13 April 2021 - 03:03 PM

Hmm, I like the idea of getting some reduction too, if possible. F/7 isn't the fastest.
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#6 Forward Scatter

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Posted 13 April 2021 - 10:22 PM

Hmm, I like the idea of getting some reduction too, if possible. F/7 isn't the fastest.

Beware....it could start the insidious slide into the hunger for even wider FOVs!  The single-minded obsession to squeeze the NA or Cal Nebs into a single image frame can never be sated. It hit me really bad. Now the days are left pining for the Cygnus Nebs to emerge from the horizon.

 

Cheers!, 

J



#7 kel123

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Posted 13 April 2021 - 10:56 PM

Beware....it could start the insidious slide into the hunger for even wider FOVs! The single-minded obsession to squeeze the NA or Cal Nebs into a single image frame can never be sated. It hit me really bad. Now the days are left pining for the Cygnus Nebs to emerge from the horizon.

Cheers!,
J


I think he is more worried more about the speed than the field of view.

#8 kel123

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Posted 13 April 2021 - 10:59 PM

Hmm, I like the idea of getting some reduction too, if possible. F/7 isn't the fastest.


I think it depends on your priority. The Altair 0.8 reducer can do the job but you should be ready to crop out the edges.

#9 ravenhawk82

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Posted 13 April 2021 - 10:59 PM

I have this one for my 72ED, which I got from Astronomics: https://www.astronom...refractors.html. There also is the 0.8X Reducer/FF that works very well for squeezing out a wider FOV which is nice for the big nebs, but is backordered.

 

There was some peripheral star coma on my 533, starting around 1/4 the frame from the edges. Not too bad, but then again we are perfectionists. This FF took care of it nicely and now the stars are really nice & round. 

 

Cheers, 

J

I use both of these (albeit the older model AT field flattener) for both my AT80ED and AT6RC. Nice round stars across the whole field of my micro 4/3rds sensor, and when I still used a D610 the field flattener did a good job of taming the stars across almost the entirety of the full frame with the AT6RC. These are both great tools to keep around.



#10 Mitrovarr

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Posted 14 April 2021 - 12:23 AM

I think he is more worried more about the speed than the field of view.

Yep. I'm just using an AVX and I don't have a guiding setup yet so we're definitely talking pretty short exposures. The next goal will be guiding, probably using my planetary camera (ASI224MC).


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