atik 414ex ccd to asi 2600 cmos and filter size or comments

[iwols]

Hi all looking at possible upgrade from atik 414 ex ccd to asi 2600 mm pro cmos and in astronomy tools it says minimum filter size is 30.73  for my ts optics 100mm scope,so would my 1.25" filters be ok or am i near the bone,also any other comments suggestions on this upgrade appreciated,im aware of the field of view side of it ,thanks  ,is it worth a try   1.25" = 31.75mm

 

[DaveS]

I measured the clear aperture of my Baader 1.25" filters at 28 mm, so too small. I would seriously consider going to 36 mm unmounted if you can.

[Adam J]

2 hours ago, iwols said:

Hi all looking at possible upgrade from atik 414 ex ccd to asi 2600 mm pro cmos and in astronomy tools it says minimum filter size is 30.73  for my ts optics 100mm scope,so would my 1.25" filters be ok or am i near the bone,also any other comments suggestions on this upgrade appreciated,im aware of the field of view side of it ,thanks  ,is it worth a try   1.25" = 31.75mm

 

So as above my AD and Baader 1.25 inch are about 27-28mm, the 1.25 inch is the thread size not the size of the clear aperture. So the cell wall has thickness. Even 31mm unmounted  filters sit on a lip that is smaller than the 1.25 inch thread and reduces clear aperture by about 2mm to 29mm. None of that stops you using the filters with a 2600 it will just result in vignetting in the corners that you may need to crop out if not fully corrected by flats. You will likely still get use of over 80% of the sensor area, so still more than a 294 would give you. But long term you will want to switch to 36mm filters to get the most from your new camera. 

However, all in all if I was not able to afford quality 36mm filters in the near future I would get the 294mm and stick with the current filters as flats will correct them fine so long as you are not imaging at less than about F4. 

 

Adam

Edited July 26, 2023 by Adam J

[iwols]

thanks guys

[Astrobug]

Go for 2inch filters, it will only hurts once

[Adam J]

3 hours ago, Astrobug said:

Go for 2inch filters, it will only hurts once

Yeah and leave you with a huge and expensive and heavy filter wheel that you will never use unless you get a full frame mono camera. If he is thinking about sticking with 1.25 to save money I really dont think the cost of 2 inch and a wheel is going to be a player.  Oh and the cost of a scope capable of covering a full frame sensor even if you had one.

Adam

Edited July 26, 2023 by Adam J

[iwols]

On 26/07/2023 at 13:16, Adam J said:

So as above my AD and Baader 1.25 inch are about 27-28mm, the 1.25 inch is the thread size not the size of the clear aperture. So the cell wall has thickness. Even 31mm unmounted  filters sit on a lip that is smaller than the 1.25 inch thread and reduces clear aperture by about 2mm to 29mm. None of that stops you using the filters with a 2600 it will just result in vignetting in the corners that you may need to crop out if not fully corrected by flats. You will likely still get use of over 80% of the sensor area, so still more than a 294 would give you. But long term you will want to switch to 36mm filters to get the most from your new camera. 

However, all in all if I was not able to afford quality 36mm filters in the near future I would get the 294mm and stick with the current filters as flats will correct them fine so long as you are not imaging at less than about F4. 

 

Adam

do you think that flats would correct the 2600 on the 1.25" just for now as i am thinking ,get the asi2600 try them on the 1.25" then move to the 36mm filter/wheel in time?

[DaveS]

I think the vignetting would be far too extreme for flats to correct.

But try it and see.

[Adam J]

11 hours ago, iwols said:

do you think that flats would correct the 2600 on the 1.25" just for now as i am thinking ,get the asi2600 try them on the 1.25" then move to the 36mm filter/wheel in time?

probably not workable, just crop it down. 

[iwols]

just looking at the 294 not sure i would be happy with the amp glow (i know it may be possible to calibrate out) and overall image calibration time,ah well my mind gets more confused thanks guys

[Budgie1]

11 hours ago, iwols said:

just looking at the 294 not sure i would be happy with the amp glow (i know it may be possible to calibrate out) and overall image calibration time,ah well my mind gets more confused thanks guys

The amp glow on the ASI294MC isn't an issue, I just use a darks library and there's no calibration issues. The only thing I found was using Bias frames caused a residual of amp glow to be left behind, so I only use Darks, Flats & Flat-Darks. 

I assume the mono version of the 294 would be similar.  

[david_taurus83]

533MM. Perfect for 1.25" filters and no amp glow. I don't even use darks now as long as I dither.

[iwols]

That's a good call but not enough difference in the field of view of my 414ex thanks though

[david_taurus83]

It's roughly the same size/area as a 460. The biggest size you can practically use is something like a 294 or 1600 size sensor, and that's with the sensor as close as possible to the filters. If you want bigger then it's bigger filters, filter wheel etc