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Old 29-01-2008, 06:15 PM
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skwinty (Steve)
E pur si muove

skwinty is offline
Join Date: Dec 2007
Location: Cape Town
Posts: 494
Hi all
The point I was making with respect to raw and iso is
1.At high iso the camera amplifies signal as well as noise by the same amount therefore no change to signal to noise ratio therefore no advantage to raw at high iso.
The noise is sampled adequately at low iso.
2.If shooting jpeg then high iso would be required or the dynamic range would suffer.

With respect to MLU perhaps the problem lies with the 30 sec reset time of the mirror.
The EOS utility software does give access to the timer for interval shooting. Perhaps I am not understanding the issues you are experiencing.

I must confess little experience with astrophotography but i have been studying the handbook of astronomical image processing by Richard Berry and James Burnell and the 40d handbook.
Unfortunately my OTA rings have still not arrived and so cannot practice what I preach. Hopefully the rings will arrive very soon.
I have a GSO 12", eq6 pro , 40DH and a hargreaves strut. I am hoping that i will be able to explore all aspects of astrophotography with this setup before having to purchase either a bigger mount or smaller OTA.

Incidentally here are 10 tips for great dslr images from the handbook

1.Shoot under dark sky
2.Use fast optical system
3.Avoid vignetting
4.Stack your images
5.Store images in raw
6.Shoot using low ISO
7.Make darks and flats
8.Mix long and short exposures
9.Dither Tracking.

Thanks for a great forum with active discussion.

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