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09-11-2008, 10:55 PM   #46
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Melander: ARGGGGHHHH!!!!!! Your photos have just activated my LBA again!! I just ordered the DA* 300/4 and now I have to get the 35!!!!! I need to talk with my loan manager at the bank....

With regard to high ISO noise, remember that noise is the result of heat produced by the CMOS sensor itself plus heat hitting the CMOS sensor. Since heat lies in the red end of the spectrum, it makes sense that the red channel will have the most noise. I think rather than pick a colder appearing lens, a more immediate impact would be to chill the whole camera. Not to the point of risking condensation if brought into a warm building. Heck, I'm going to try this myself. Perhaps we need the DSLR equivalent of those liquid CPU coolers you see in the gamer computers to stop chip meltdown.

Jack

09-11-2008, 11:15 PM   #47
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I don't quite get it. The camera is producing more noise at higher ISO (and even in shadows in lower areas) than some other cameras. Not a great performer, nor an especially poor one (although...) Now, some of us might love noise, others might not love it. Some of us might like the noise to start at ISO 6400 hence allowing Pentax to up the ISO range and allow us to take those same "acceptable" images at ISO 12800 and up.

The question of the noise seems relevant to me only when comparing it with other cameras and better ISO performance is desirable for the reason stated before, it would allow you to take pictures in a wider range of situations.

Does the performance of the K20d at hight ISO make it a crappy camera? Of course not, and decent images can be had at higher ISO, but this does not invalidate other reviews nor the more general point about the noise.

Noise is, in my humble opinion, a pretty complex subject that most people do not understand properly (count me in, I think I barely begin to understand it's complex and don't pretend to understand it completely, yet) and many people will make wrong generalizations based on topics such as this one, where people show only their best results with high ISO (expose to the right, high contrast pictures with few subtle shadows, etc.)

Sorry, I understand this topic is only meant to show nice pictures at high ISO not emit opinion (although I'm going to say I present facts here not opinions :-) but I think staying on the realm of the objectivity at least a bit would help.

I've added a boring ISO 1600 shot of my own, indicating the absence of noise when resizing pictures to display them on the forum. The image has noise when zoomed in, obviously.

Another question, instead of taking more than one exposure, if the subject stays still for that long (at most 1/3 sec, right?) why not just increase the shutter speed and decrease the ISO, hence removing noise? The advice sounds reasonable but for a pretty limited amount of circumstances, right?
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Last edited by letomuaddib; 09-11-2008 at 11:18 PM. Reason: Added question about two exposures
09-13-2008, 11:21 PM   #48
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Here is my contribution to the thread. K20D at ISO 6400, 1/180s, f5.6 with a SMC-P 300*/f4 and a 2X teleconverter. Converted to jpeg by Rawtherapee with no enhancements/filtering, etc. Note the exif focal length info is wrong because I forgot to change the lens info when turning on the camera. This is the 35mm film equivalent of a 900mm lens so, yes, the SR works well.

http://farm3.static.flickr.com/2288/2855490964_defd99d2b3_o.jpg

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09-13-2008, 11:35 PM   #49
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iso1600 and handheld









09-14-2008, 02:13 AM   #50
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QuoteOriginally posted by melander Quote
Took these on a small alternative music festivall in my home town. Iso 1600 on all of them. Pentax K20D, Pentax DA 35/2,8 Macro Limited. All of the pictures have gotten a mild threatment in noise ninja. (standard settings, just did the profile image and ran it)
I am impressed with the qualities of yours Melander!
Who are those bands?, the top one looks like Alexi from Children Of Bodom?!

Good work!
09-14-2008, 04:18 AM   #51
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hey everyone, first of all - great shots all around
next, why is noise an issue at all? I mean, in my digital begginings, first thing I'd look when reviewing a camera was iso and noise. In time, I learned that there's really no point in judging camera's high iso with 1sec exposure at iso1600 in pitch black night...
Then with my experience, I started to look first at contrast, colors, and things like that, then noise. Then, came time to value noise problems in printed photos, not 1:1 pixel peeping on some crappy LCD display, and now - I don't mind noise at all. If image is really that noisy, for example, if I pushed 2 stops more from RAW at iso1600, I simply switch it to B/W and there's good old grain, as it's supposed to be in BW prints, right?
I have k10d, and I just love that rounded noisy jpg look that comes out, I can't get that "grain" while converting from RAW. I guess that noise really is problem only if you get really messy photo in 30x20cm print, details eaten away and everything in red/yellow cast. As far as internet, forums and uploading images go, we all downsize our shots, and you can easily clean those up without any loss. so, for my money - noise is not an issue
09-14-2008, 07:53 AM   #52
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letomuaddib:
QuoteQuote:
Another question, instead of taking more than one exposure, if the subject stays still for that long (at most 1/3 sec, right?) why not just increase the shutter speed and decrease the ISO, hence removing noise? The advice sounds reasonable but for a pretty limited amount of circumstances, right?




Did you mean decrease the shutter speed?
09-14-2008, 01:10 PM   #53
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Some night shots with K20D

ISO 1600, handheld 1/3 s

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09-14-2008, 09:17 PM   #54
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QuoteOriginally posted by silent_eyes Quote
hey everyone, first of all - great shots all around
next, why is noise an issue at all?[...]
Look at it this way: You can buy all the equivalent of your lenses 2 stops faster (and at least twice as expensive per lens.) Or the next Pentax camera could have noise levels at 6400 similar to the current 1600, hence allowing your lenses to be 2 stops faster in low light situations.

For someone having a lot of glass, better ISO performance should be a very attractive proposition. Also, the other brands are making good progress in noise level handling hence the "bargain" qualities of Pentax might not be as interesting if they don't keep high ISO performance at competitive levels. Not necessarily lead the pack but keep in the pack on this point, too. Oh, and the increase in stops of your lenses is a bit of a simplification (faster glass is not just faster, it usually tends to be optically better as well) but I think the more general point is valid.

This is why I'm saying looking at noise in itself and just say you like grain qualities is nice but it's not the whole picture.

Jewelltrail: You are, of course, correct: decrease the shutter speed. Thank you.
09-15-2008, 03:25 PM   #55
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Took this using a scope at 30x giving me F/16 at ISO 3200, some careful PP and a K20 14mp JPG cropped.

Last edited by wildman; 12-26-2008 at 01:00 PM.
09-20-2008, 06:48 AM   #56
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Camera: Pentax K20D
Exposure: 0.003 sec (1/400)
Aperture: f/6.7
Focal Length: 500 mm (Sigma 50-500)
ISO Speed: 3200
Exposure Bias: 0/10 EV
Flash: Flash did not fire



Camera: Pentax K20D
Exposure: 0.008 sec (1/125)
Aperture: f/6.3
Focal Length: 270 mm (Sigma 50-500)
ISO Speed: 1600
Exposure Bias: 0/10 EV
09-20-2008, 04:16 PM   #57
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ISO 6400 with Neat Image

This is a ISO 6400 with a basic neat image pass. Since most other camera's (especially in reviews) have noise reduction on by default this would be fair as long as your workflow involves post processing. But I must admit the in-camera NR done by the new Canons is very very good. Click on the image of you want to access to the full (original) size image.




Camera: Pentax K20D
Exposure: 0.017 sec (319566/19173959)
Aperture: f/2
Focal Length: 50 mm
ISO Speed: 6400
Exposure Bias: 0 EV
Flash: Flash fired
09-20-2008, 05:02 PM   #58
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Property#!, as soon as I saw your photos I knew you'd been to the Toronto zoo. I never did get a decent shot of a Tundra wolf through that fence. Very nice.

Last edited by audiobomber; 09-20-2008 at 10:04 PM.
09-20-2008, 07:49 PM   #59
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QuoteOriginally posted by PentaxPoke Quote
Would you like the exposure settings? I can go back and add those.
You should not normally have to "add" the info. It appears you may be "saving for web" or another method which strips that info from your images. At least, when I right click them with Panda it says no exif available....

Here is one from my own high-ISO test. Cropped vertical from a horizontal shot (and a bit more) as I will put a few side-by-side for another post. Oh, it has exif as well :-) ISO 3200.
Attachment 19026

Last edited by SpecialK; 06-04-2015 at 08:04 PM.
09-21-2008, 03:35 PM   #60
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My daughter wanted to see the DaVinci exhibit at the Witte Museum in town and i was kind of peefed when i saw the small halogens lighting the exhibit ("Great, how am i gonna get something useful HERE?" ran through my mind), at ISO1600 i got handholdable speeds and went ahead shooting an exhibition at an ISO speed i never dared to use on my 30D in low light, i was positivily surprised to see the results to say the least. Looking for samples for my sales thread i remembered i wanted to add something to this, so here they are. I know 1600 is not 6400, i still am impressed each time i see them.
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