Re: [APML] OT: Nikon D2H Astrophotography Tests

[Jerry Lodriguss <jerry@astropix.com>]

>
>Nice review. That must have been alot of work.

Hi Rob,

A little bit more work because I had to manually trip each exposure and 
they were only a couple of minutes each. Not like just opening a 60 minute 
exposure on film and then taking it easy for an hour. <G>



>Because of the way these cameras acquire color ( not all the pixels
>are used at once) they will not have the same resolution as the monochrome
>astronomical CCD cameras.

I'm not quite sure what you mean when you say not all the pixels are used 
at once, this is not my understanding of how the Bayer pattern cameras work.

I've read that the resolution is the same for the luminance data, where 
each pixel is used, but that the color data is what is sacrificed, and even 
then, it's a pretty clever algorithm that is used to reconstruct the color. 
Of course, there is no arguing that these consumer digital cameras are 
vastly inferior to a dedicated cooled CCD astro camera in a lot of other ways.

On the other hand, they do have their advantages, such as price and sensor 
size/pixel density.




>Also the blue halos and distortion of the stars
>are more likely due to the performance of the 400MM F2.8 lens. These lenses
>are not apochromatic or even close.


Yes, I tend to agree with that.   On the other hand, this performance is so 
bad, I really have to wonder if something is wrong with the lens, or if 
something else is going on (perhaps bad focus too).



>CCD's will bring out all these optical
>flaws.With film the optical flaws of these lenses are masked by the 
>overall low
>resolution
>of the image.

Now I don't think that is true. I've seen this exact same kind of poor lens 
performance with a 300/2.8 ED Nikkor on shots taken on E200 film.

Both the 300 and 400 are the latest Nikon models too.  I didn't think it 
was possible for my opinion of Nikon to get any worse, but even despite the 
promise of the D2H, it has.

Jerry




Photoshop for Astrophotographers - http://www.astropix.com/PFA/PFA.HTM











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