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10-14-2009, 11:04 PM   #226
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K20D, Tamron 28-75F/2.8 ISO 6400
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10-24-2009, 01:35 AM   #227
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I must say I was very surprised at the high ISO performance of the Pentax k-m. This is an unprocessed image taken at ISO 3200.

This camera produces very useable images at high ISO's.

10-24-2009, 02:52 AM   #228
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K20D ISO 1600 quick portrait:

11-02-2009, 11:40 AM   #229
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QuoteQuote:
Ash: K20D ISO 1600 quick portrait:
Great shot Ash.

11-02-2009, 12:00 PM   #230
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Here are 2 from my K20D and DA*50-135 at ISO 3200. There is some noise in the night sky.



11-18-2009, 06:12 PM   #231
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OK, the K-x has been out for long enough. Time to resurrect this thread and get some K-x images here!

I don't have a K-x, but my K200D hasn't decided to start sucking, either :-) ISO 1600 pushed 2/3 of a stop to the equivalent of around 2400:

11-20-2009, 07:04 PM   #232
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K-x ISO1600
F3.5 1/25s 18mm

11-20-2009, 07:34 PM   #233
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QuoteOriginally posted by Marc Sabatella Quote
OK, the K-x has been out for long enough. Time to resurrect this thread and get some K-x images here!

I don't have a K-x, but my K200D hasn't decided to start sucking, either :-) ISO 1600 pushed 2/3 of a stop to the equivalent of around 2400:
Can you please explained what ''ISO 1600 pushed 2/3 of a stop to the equivalent of around 2400:'' means?
thanks

11-20-2009, 11:31 PM   #234
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QuoteOriginally posted by jgredline Quote
Can you please explained what ''ISO 1600 pushed 2/3 of a stop to the equivalent of around 2400:'' means?
thanks
If you underexpose a picture by a given amount (like 2/3 stop) and then increase the exposure by that same amount in PP, the effect is *exactly* like shooting at a correspondingly higher ISO. That is, you get the same faster shutter speed you'd get by turning up ISO, and the same increase in noise. There's no difference.

So, for instance, if you are at ISO 1600 and find you need a shutter speed of 1/15" to get a correct exposure at f/2.8, and you decide 1/15" just isn't fast enough, you could raise ISO to 3200 - thus giving you a shutter speed of 1/30" but increasing noise. Or you could simply increase the shutter speed to 1/30" while leaving ISO at 1600 - thus giving you a picture that was one stop underexposed and needed to be brightened digitally in PP, yielding more noise. The end result would be in all respects exactly the same either way - a shutter speed of 1/30" and more noise that the original picture at 1/15" and ISO 1600.

In fact that's how very high ISO values are actually implemented in most cameras - the analog signal amplifier tops out at ISO 1600 (or whatever), and higher ISO values are shot underexposed at ISO 1600 and then brightened digitally in the camera's firmware (yes, even for RAW).

Since the K200D doesn't have ISO settings above 1600, I do all my "extreme" high ISO shooting using the technique I described.
11-20-2009, 11:35 PM   #235
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QuoteOriginally posted by Marc Sabatella Quote
If you underexpose a picture by a given amount (like 2/3 stop) and then increase the exposure by that same amount in PP, the effect is *exactly* like shooting at a correspondingly higher ISO. That is, you get the same faster shutter speed you'd get by turning up ISO, and the same increase in noise. There's no difference.

So, for instance, if you are at ISO 1600 and find you need a shutter speed of 1/15" to get a correct exposure at f/2.8, and you decide 1/15" just isn't fast enough, you could raise ISO to 3200 - thus giving you a shutter speed of 1/30" but increasing noise. Or you could simply increase the shutter speed to 1/30" while leaving ISO at 1600 - thus giving you a picture that was one stop underexposed and needed to be brightened digitally in PP, yielding more noise. The end result would be in all respects exactly the same either way - a shutter speed of 1/30" and more noise that the original picture at 1/15" and ISO 1600.

In fact that's how very high ISO values are actually implemented in most cameras - the analog signal amplifier tops out at ISO 1600 (or whatever), and higher ISO values are shot underexposed at ISO 1600 and then brightened digitally in the camera's firmware (yes, even for RAW).

Since the K200D doesn't have ISO settings above 1600, I do all my "extreme" high ISO shooting using the technique I described.
Thank you. This is very helpful...
11-21-2009, 01:34 PM   #236
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K20D is still kicking too!

Boring, boring, but perhaps instructive - ISO 640 followed by 3200. Not bad, IMO.






This is ISO 800 - not really "high", but fully, utterly usable results always:


100% Crop:


Here's an ISO 3200 macro shot (birdseed,) no NR of course:

11-21-2009, 01:51 PM   #237
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I usually don't do shots above 800 ISO with the K20D, but here is one from last year with ISO 1600

12-07-2009, 04:25 PM   #238
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Iso 3200 K-m
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12-07-2009, 07:00 PM   #239
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QuoteOriginally posted by Marc Sabatella Quote
OK, the K-x has been out for long enough. Time to resurrect this thread and get some K-x images here!

I don't have a K-x, but my K200D hasn't decided to start sucking, either :-) ISO 1600 pushed 2/3 of a stop to the equivalent of around 2400:
Marc, sorry but I don't understand ... as usual: "pushing" 2/3 stop: do you mean increasing exposure by 2/3 Ev while still at ISO 1600?
Would this really help with noise?
Confused.
JP
12-07-2009, 07:04 PM   #240
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Pentax Kx -


ISO3200


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