Questions regarding FOV in relation to OTA and camera.

[JR1987]

I currently shoot on a skywatcher 200PDS with a Canon 100D, and ive quickly noticed how my FOV is quite limited. Ive been looking into other options as I want to shoot some much bigger targets.. so ive been thinking about it and doing some research and I think maybe adding an ED80 to the gear list may benefit me with regards to shooting a much wider field. And then I started causally looking at CCD cams and it got me thinking.

When I used this FOV calculator (I think FLO made it) I noticed with an Atik 414EX and the 200PDS the field of view is really small, and the opposite with the ED80 and the canon.. So it might be a silly question..but does for example using the Atik with the 200p suit shooting much smaller targets because the field of view is smaller and perhaps more concentrated? And obviously the opposite go's for the the ED80

Ive attached some examples of what I mean below 

[Merlin66]

James,

From your illustrations, I think you've answered your own question.....

[D4N]

Field of view shouldn't be the only consideration, pixel scale will be completely different between the two scopes.

Check out http://astronomy.tools/calculators/ccd_suitability

The small chip on the 414ex won't be hit by a lot of the light cone but it will benefit from only having light from the centre of the cone as this tends to be better corrected.

/Dan

Sent from my iPad using Tapatalk

[r3i]

Spending some time with a FOV calculator is very worthwhile if you're considering getting a new scope and/or camera so that you have a good idea about what will and won't make suitable targets.  Another option if you have a limited FOV is to put together a mosaic of images.

[geordie85]

I had the same thoughts so now I'm saving for a Williams optics star 71 and an atik 383l which should give me a fantastic FOV

[ollypenrice]

You can make a small object fill the sensor by

1)  having a smaller sensor, or

2) increasing your focal length.

There is absolutely no point whatever in the first option because the object will be no bigger, it will just have less sky around it. 

However, bear in mind that when an image is at '100%' on a PC screen that means that one camera pixel is given one screen pixel. If you have a sensor of a given size then the one with the smaller pixels will give a larger screen image.

Olly