Ocular Plugin: What is the best FOV to get accurate Image sensor Frame

I can not recreate this. On all of my machines, the angular size stays exact as the FOV changes. And as the FOV calculation is directly tied to that of the screen, I can not imagine any way for it to be out of sync as you suggest.

Thanks Tim for your reply.

Here are images and definitions of ocular.ini

https://photos-1.dropbox.com/i/l/7GQYQMxIGEwiG-EYWgRayxPBJHghyXDSbBUea0U3ztY/86747692/1347447600/4e178ab/stellarium-023.png#1

https://photos-2.dropbox.com/i/l/RSVx5ALgNG8Y6IGQ8lS7H-tzb5tboTlncot3yjKb62k/86747692/1347447600/3559e47/stellarium-024.png#2

The info box states that dimensions are ~ 47.5 X 71 degrees

My definitions are as follows:

[telescope]
0\name=Canon 18 mm
0\focalLength=18
0\diameter=67
0\vFlip=false
0\hFlip=false
1\name=Canon 300 mm
1\focalLength=300
1\diameter=67
1\vFlip=false
1\hFlip=false
2\name=C1400
2\focalLength=3190
2\diameter=355.6
2\hFlip=true
2\vFlip=false
3\name=80EDF
3\focalLength=500
3\diameter=80
3\hFlip=false
3\vFlip=false
4\name=My Telescope
4\focalLength=500
4\diameter=80
4\hFlip=true
4\vFlip=true
5\name=Meade LX 90
5\focalLength=2000
5\diameter=200
5\hFlip=true
5\vFlip=false

[ccd]
0\name=EOS 600D
0\resolutionX=5184
0\resolutionY=3456
0\chip_width=22.2999992370605
0\chip_height=14.8999996185303
0\pixel_width=15
0\pixel_height=15
1\name=5D Mark 3
1\resolutionX=5760
1\resolutionY=3840
1\chip_width=36
1\chip_height=24
1\pixel_width=6.25
1\pixel_height=6.25

And as I've stated, I can not recreate this. It works as expected on all machines I've tested on.

I can't reproduce this issue too. Khalid, can you check CCD frame size for all others "telescopes"?

Hi Alex

I could recreate this with another windows 7 system.

And here are my findings:

- CCD + pre-defined telescopes or any definition with a long focal length, that produce a frame that covers a small FOV angle appears not to have the issue (or the problem is not noticeable).

- CCD + a short focal length (I tried with 10, 18, 50 mm focal lengths) will have the problem. You can test the pre-defined CCD for 450D + a lens with 18mm focal length.

- The behaviour is different for different projections. For example, Hammer-Aitoff is ok while stereographic is not (I use stereographic)

these are sample images using stereographic projection:

http://dl.dropbox.com/u/86747692/Stel_Screenshots/stellarium-025.png

http://dl.dropbox.com/u/86747692/Stel_Screenshots/stellarium-026.png

Hmm. Yes, I can reproduce this issue on telescopes with short focuses.