Meade DSI 2 Field of View

[Pecky1]

I have just started out in astro photography. I have a Meade DSI 2 colour camera, and I am not sure how to adjust the field of view, as the image appears to be greatly magnified and way to large. Most of the objects just aren't able to fit on the screen. Any advice will be welcomed!! :)

Pecky1

[Merlin66]

More information needed....
Which telescope?
How is the camera mounted onto the scope?
The field of view is determined by the effective focal length.
The freeware CCDcalc shows the various FOV with different scopes etc.

[scagman]

Hi Kevin,

Welcome to IIS.

The DSI 2 has a very small sensor. Its only 8mm diag.
I've attached an image of the horsehead neb. I took with a DSI 2 thru a ED127 and a link to an image of the same image taken with a QHY8 which has a sensor size of 28.4mm diag. Also taken using a 127mm.

The linked image was taken by Finao(Astrod00d) and I hope he doesn't mind.
http://www.iceinspace.com.au/forum/showthread.php?p=368832#post368832

Hope this helps and gives you and idea of the size, but dont compare the quality of the 2 images, I'm only a beginner.:)

Cheers

[loki78]

As Ken said CCDCalc will give you the Field of View of specific Scope/camera combos, you can also use this website to do the same thing.

http://www.12dstring.me.uk/fov.php?aperture=100&flength=900&barlow=1&pxsize=4.31&pxwidth=5184&pxheight=3456&binningw=1&binningh=1&day=5&month=8&year=2012#

[Pecky1]

I am using a Meade 12" LX 200 ACF. Focal Length is 3048mm F/10. The camera is mounted where the eyepiece goes.

[Pecky1]

Thanks Folks! I have a better understanding of what is going on now. One more question - would a focal reducer help to down size the image, or would it interrupt the light transmission to much?

[loki78]

The focal reducer will give you a wider field of view. Just how much, you can select that in both that website link or CCDcalc when you select your scope/camera you can also select if you're using a barlow/focal reducer which will scale the image accordingly to show you your field of view.

[Garbz]

Quite the opposite of interrupting light transmission. Your objects will be the same amount of light but projected onto a smaller area, i.e. brighter.

By using a reducer you will need shorter exposures to get the same brightness.