Quote:
Originally Posted by Ross G
Nice photo Ray.
Great detail.
Ross.
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thanks very much Ross
Quote:
Originally Posted by clive milne
It's a curious thing, others have tried and failed with that corrector even though it leaves little to be desired optically (when used with a small format sensor). I would put that down to BFD spacing errors giving the Rowe corrector a bad rep' when it isn't applied properly. You seem to have it nailed though.
I'd be interested to see one of your full frame raw images at native resolution. Without seeing that, I couldn't say for certain, but I suspect your system limit is charge diffusion. For a given focal length, that's as good as it gets from the perspective of the application of opto-mechanical principles pertaining to ccd imaging.
regards,
~c
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Hi Clive. Will post a raw frame when I have one without field rotation.
For interest, I modelled the system as an obstructed aperture PSF convolved with Gaussian atmospheric blur. Also included a simple charge diffusion term and found that diffusion is not a major issue for this system until it is above about 20% - it would be much more of a problem in undersampled systems. I could not find any crosstalk data for the icx694 (or anything else for that matter), so used 10% for the graph attached. I do not have any independent measure of seeing, so the starting point of 1.5 arc sec was a guess, but the data fit well enough that it seems reasonable to say that the system is practically seeing limited. The real data includes tracking, scattering and stray diffraction (particularly the spider), but the model does not, so the divergence of the curves seems reasonable.
regards ray