#41  
Old 04-05-2006, 06:50 PM
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Yeah, Christian is sort of right. Like i said it doesnt have Median filtering, but it also does..Politicians talk..
In reality, if the NR is OFF (Not Long Exposure NR), then upto 800 ASA the image is dead raw. If you use a higher ISO e.g 1600, 3200 then it has minor filtering which was tested by some big name reviewers and they confirmed its not anything to worry about, unlike previous models. Thats why i stoped going anymore than ISO 800 on the tests.
I wont use anything faster than ISO 800 anyway, plus i also checked the quality of the image and i cant see any difference. Stars were still pinpoints and nebuale showed up clear and sharp.
I would let others decide if its bad or good when they see the images them selves. All the reviewers say when switched off the images are sharper on the higher ISO's, all be it with a little more noise. But below ISO 800 its 100 % OFF. When the NR is ON then the minimum ISO is 400 before any filtering is done, soo below ISO 400 it again is not touched.

Hehehe i went to the site, but pour le voue Francie NO !. I'll just send you to a Greek site next time !!!!.
Now i think they documented the Spectral response for the 20D and the 5D i dont think thats correct, as i would assume the 5D would be much better than the 20D. But maybe it is..Dunno...
Im sure that it would be a matter of time before there was a patch for the D200 to remove or at least bypass filtering at all ISO levels above 800.
This is why i think many people beleive that the D50 has lower noise, cause i really think theres more filtering going on than the D70 at the same ISO.
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  #42  
Old 04-05-2006, 07:07 PM
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One thing i left out.. The Hot filter does make a great difference to Q.E. Just look at the 300 or 350 Mod, and check the spectral purity and response. Huge difference.. Remember even 3% increase is regarded as Huge these days.
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  #43  
Old 05-05-2006, 01:39 AM
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Here is info on the dynamic range for both the Canon 5D, plus a link to a comparison of the 2.
http://www.brisk.org.uk/imatest/C5D_MCollins1.html

http://www.digitalcamerainfo.com/con...ge-Quality.htm
Heres a quick comparison with the D200.
http://www.digitalcamerainfo.com/ima...e-Graph2-D.jpg

Last edited by Gama; 05-05-2006 at 03:34 PM.
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  #44  
Old 05-05-2006, 05:38 AM
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iceman (Mike)
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Guys, please keep the discussion civil. There's been a few instances of comments bordering on "out of line", and one I just had to delete was out of line.

This is a great and frank discussion between some obviously experienced amateurs who are passionate about their hobby. Let's keep the information flowing, and keep the personal comments out of it.
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  #45  
Old 05-05-2006, 09:38 PM
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Gama,

Thats interesting about ISO800 and lower being devoid of the median filter (well its some sort of filter). A very interesting development and to me would remove the biggest negative of this camera.

From what I have seen IO400/800 is about optimal unless you do very short exposures.

I agree QE increases dramatically with the removal of the hotfilter, but primarily > 550 nm. Around green it makes a few percent difference.

So you have a hard time understanding French? This is where I got my original information to modify the 300D

http://www.seo-e.co.jp/hobby/EOS300D/EOS300D.htm

Terry
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  #46  
Old 05-05-2006, 10:13 PM
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Hahaha, i really thought it was a legit site..Stung twice.

With the NR filter, yeah that was good news to me too that they didnt fudge the Raw image at all up to ISO 800. Im in the same boat as you, i cant use anything higher than 800 cause of the sky background where i am. It saturates at around 3 minutes at 1600 and very white at 800.
But at 400 its really nice, and 200 is fantastic. But i needed to make sure they (Nikon) wernt blowing smoke up my dress..(Figure of speach!).
So i tested it up to ISO 800 and yep, they were correct, not a prob.
What is amazing is just how far DSLR has come in the last few years.
I was looking at some images by a Yankee Robotics Trifid II, and comparing them with images from modded DSLR's, and you cant pick it. Just taken for granted that it will take some nice family pics, but as a poor mans Asto camera.
But in fact its now a smart mans tool, does everything you need for getting some really high quality shots.
Boy, i remember buying my first CCD camera when they first started comming out. It was the Meade 216, got it about 9 years ago, and it produce breathtaking images (Which i laugh at now)then, but now would rather use a stone and chisel to image instead of it.
While surfing around i stumbled on a site that showed the CCD's that were made for the U.S. Military, man it was HUGE.. 4" Square.. They reckon it was the largest single CCD in the world. (No Cmos here.. hehe just kidding).
I'll try and find that site again.
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  #47  
Old 06-05-2006, 03:03 AM
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Vermin (Tom)
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Gama, I get what you're trying to do but you can not convince me to convert now.

I have just spent nigh on $8000 for Canon EF lenses (f2.8 or better from 16 to 200mm @ 35mm frame).

I only had enough left over for the 30D (after adding a GM8, f10 guide scope and guide Toucam, that can also be used for planetary imaging).

I may upgrade the camera body in future but you'll have to pry these lenses from my cold dead hands. Nikon, just did not rate when I looked closely at the lens reviews.
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  #48  
Old 06-05-2006, 05:42 AM
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This was not meant to convert anyone. The Canon 10D, 20D etc are by all means fantastic cameras for Astro imaging. Why convert.. theres no reason too, they do just as much a good job as any good imager.
The review is just that. If i reviewed a SBIG STL 11000CM, would that mean you would convert and buy one ?..
This is for anyone wanting some info about another good camera for Astro work. Nikon was not looked upon as a viable camera for this sort of work, but i hope now people take a different view, and start posting some good ones with them.
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  #49  
Old 06-05-2006, 02:44 PM
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Quote:
Originally Posted by Vermin
Nikon, just did not rate when I looked closely at the lens reviews.
Then I wouldn't take too much notice of those reviews. Nikon (and Canon) make superb lenses, but it's all about how much you want to spend. An expensive lens in either brand will perform very well. To say one is better than the other would be like splitting hairs in most cases, to say Nikon lenses "just did not rate" is a bit much I think.
Another thing though, you do have the advantage of being able to use Nikon lenses on a Canon body (with an adapter ring) so you can pick and choose the best each brand has to offer, if you really want to. It doesn't work the other way around with Canon lenses and Nikon bodies unfortunatly.
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  #50  
Old 06-05-2006, 03:07 PM
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Quote:
Originally Posted by gama
With the image you took, it was taken with a 150mm (6 Inch) lens, not a cheap 60mm (2 inch) telephoto, so you cant really compare timing exposures.
Noise levels of an exposure at a given ISO of say 1/250th of a second does not vary with aperture. It will vary with temperature but whether it's taken with a 150mm lens, a 50mm lens the noise level will still be the same. If it did vary there would be no point in dark frame subtraction.
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  #51  
Old 06-05-2006, 06:43 PM
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Quote:
Originally Posted by acropolite
Noise levels of an exposure at a given ISO of say 1/250th of a second does not vary with aperture. It will vary with temperature but whether it's taken with a 150mm lens, a 50mm lens the noise level will still be the same. If it did vary there would be no point in dark frame subtraction.
This reference was made for signal, as more signal is built up faster than with a smaller lens. You read it out of context. The image of a 150mm lens will produce a faster image than a 60mm of the same folcal length, as the f ratio is much smaller.
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