Skyhound Forums
General Constraints - Printable Version

+- Skyhound Forums (https://skyhound.com/forums)
+-- Forum: SkyTools Support (https://skyhound.com/forums/forumdisplay.php?fid=20)
+--- Forum: SkyTools 4 Support (https://skyhound.com/forums/forumdisplay.php?fid=46)
+--- Thread: General Constraints (/showthread.php?tid=434)



General Constraints - Nemesis@3319 - 2018-12-30

Does a single value represent the FOV of an imaging system?

Nemesis


RE: General Constraints - theskyhound - 2018-12-30

Hello,

The FOV of an imaging system normally is two values, one for the longest part of the camera FOV and one for the shorter. If the camera FOV is square, then I suppose it could be said to be ultimately represented by a single value.

I'm trying to get at what you are really asking though. Perhaps it would help to explain that the FOV of a camera is not entered, but calculated from the number and size of the pixels plus the focal properties of the optical system.


RE: General Constraints - Nemesis@3319 - 2018-12-31

(2018-12-30, 09:55 PM)theskyhound Wrote: Hello,

The FOV of an imaging system normally is two values, one for the longest part of the camera FOV and one for the shorter. If the camera FOV is square, then I suppose it could be said to be ultimately represented by a single value.

I'm trying to get at what you are really asking though. Perhaps it would help to explain that the FOV of a camera is not entered, but calculated from the number and size of the pixels plus the focal properties of the optical system.

Greg,

I have included several attachments that might help explain my confusion. But to put it simply SkyTool3 lists image size in Pixels and (Frames if DSO object is larger than the imaging system's FOV). However, SkyTools4 shows image Size in Tiles. If I understand SkyTools4 correctly, this might be the number of camera's FOV shots to encompass the image in question (X times Y tiles etc.). Example; M57 Ring Nebula picture (attachment #1) was taken with a single exposure. The setups for SkyTools 3 and 4 were as shown in (Attachments #2, 3 ,4, 5, 6 and 7). SkyTools image size comes very close to predicting this (114x114pixels) However, SkyTools4 predicts it should take 62x62 tiles, If a tile is approximately equal to my system's FOV then SkyTools4 says I cannot take a shot of M57 without using many tiles. Hence my confusion. 





RE: General Constraints - theskyhound - 2018-12-31

Hi,

I don't see your attachments, but did you see my response to the other thread you started? Assuming the issue isn't overlap, then the difference must be due to the way you have things set up.

Some thoughts:

There are several ways to create a mosaic. Which one are you using?

Start at the beginning: does ST4 accurately describe a single FOV?


RE: General Constraints - Nemesis@3319 - 2018-12-31

Greg,

Thanks for trying to help.


RE: General Constraints - theskyhound - 2018-12-31

Hello,

I would like to actually help. Why not try again with the attachments? What sometimes goes wrong is that you have to remember to press the "Add Attachment" button to the right of Browse in order to add the attachment after selecting the file. That seems unnecessarily complicated to me, but that's how it works.


RE: General Constraints - Nemesis@3319 - 2018-12-31

Greg,

I have included several attachments that might help explain my confusion. But to put it simply SkyTools 3 lists image size in Pixels and (Frames if DSO object is larger than the imaging system's FOV). However SkyTools 4 shows image Size in Tiles. If I understand SkyTools 4 correctly, this might be the number of camera's FOV shots to encompass the image in question (X times Y tiles etc.). Example; M57 Ring Nebula picture (image #1) was taken with a single exposure. The setups for SkyTools 3 and 4 were as shown in (images #2, 3 ,4, and 5). SkyTools 3 image size comes very close to predicting this (114x114pixels) However SkyTools 4 predicts it should take 62x62 tiles, If a tile is approximately equal to my system's FOV then SkyTools4 says I cannot take a shot of M57 without using many tiles. This was why I asked the question about whether a tile was approximately equal to the imaging systems (cameras) FOV. 



RE: General Constraints - theskyhound - 2018-12-31

Hello,

I think I see the issue. In SkyTools 4 you have the aperture and focal length set to meters. It looks like they should be mm.


RE: General Constraints - Nemesis@3319 - 2019-01-01

Greg,

Thanks that was it dumb mistake on my part.