The 1100D is a 14bit camera and is coming down in price. This is what JTW have to say about it.
Greysonline - 350 to self mod.
Quote:
|
We also chose the 1100D because of the pixel size, the main reason for a CMOS based camera's low QE is due to the industry's relentless pursuit of smaller pixels. Great for regular photography, but not for astrophotography. The 1100D has pixels of 5.2µm (surface area of 27µm²) , much bigger than the 600D or 650D (4.3µm, surface area of just 18.5µm²). The 1100D is more sensitive because of this. You may say that the max ISO is much higher on the 650/600D but this is just an off-chip amplification, ISO makes almost no difference to the sensitivity or signal to noise ratio. Taking an average European night with seeing of 1.5 arc seconds, and a fast widefield telescope (600mm) the camera is sampling almost 1:1, meaning the sensitivity is maximised and there is no data loss. If the seeing is worse or the telescope focal length is longer, you will be oversampling. The 1100D really is the best tool for the job
|
.
http://www.jtwastronomy.com/products/ultimate.php
You don't need a 5D mark anything. If the camera is going to spend all its time on the scope and autofocus is not an issue, the least expensive mod is to remove both filters and use an external or clip-in UV/IR filter. You could just remove the IR cut filter and reinstall the front UV/IR filter, but it is also an anti-aliasing filter and images will be less sharp.
Full mods are OK for reflective optics if not using filters. Anything with a lens requires a UV/IR filter.