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10-28-2010, 08:23 AM   #16
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QuoteOriginally posted by Gimbal Quote
Ops, missed that post.

But I don't think it is a reflection. It's much too sharp. It might be a bug in the rawconverter though.
Exactly...
I left highlight protection enabled in RPP thinking it wouldn't bother since there didn't seem to be any blowouts in the scene. However... I noticed afterward that it left these gray patches where highlights were clipped.

That being said, there's nothing wrong with the image per say.
I'd run another RAW through without this setting, but since dgaies has just recently announced he's going to re shoot the set(to compensate for missing ISO's). I'm going to hold off for the next samples.

10-28-2010, 10:01 AM   #17
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Anybody else out there with a really crappy laptop monitor? I'm on one and it let's you see ugly areas much easier than a good monitor it seems. Anyway, there are a lot of artifacts in the 200 sample that are not there in the 3200 sample, even full size? Anyone else seeing this?
10-28-2010, 10:06 AM   #18
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QuoteOriginally posted by Jodokast96 Quote
Anybody else out there with a really crappy laptop monitor? I'm on one and it let's you see ugly areas much easier than a good monitor it seems. Anyway, there are a lot of artifacts in the 200 sample that are not there in the 3200 sample, even full size? Anyone else seeing this?
My wife has our notebook atm.
However I did try a little with some extreme viewing angles to see if I couldn't pick-up something. But that didn't help much.

Also when you say artifacts, are you implying image distortions or detail?
And more importantly, where are you seeing these(location)?
10-28-2010, 11:57 AM   #19
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Blocky squares, most noticeable in the shadow areas on the left and right sides, at most viewing angles.

10-28-2010, 12:11 PM   #20
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QuoteOriginally posted by Jodokast96 Quote
Blocky squares, most noticeable in the shadow areas on the left and right sides, at most viewing angles.
Okay thanks
I looked them over again(both samples) at the edge and couldn't see anything.
I did this in a pitch dark room and pushed my screen gama to try and see them(but nothing).

Having said that.. if I had to guess, I'd say the screen you see this from from maybe causing some of the gradients areas at the finer end of the scale to display abruptly rather than smoothly.

Other than that, I'd have no clue as to what might be causing this.
10-28-2010, 12:16 PM   #21
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Need more examples!
10-28-2010, 02:14 PM   #22
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I'm thinking you're right, but that brings up another question. How much DR is lost at the higher ISO?
10-28-2010, 02:20 PM   #23
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QuoteOriginally posted by Jodokast96 Quote
I'm thinking you're right, but that brings up another question. How much DR is lost at the higher ISO?
Unfortunately, I don't have the means to measure DR in any effective way.

However... speaking from a a personal observation, I'd say ISO3200 seems to retains a great deal of overhead at both the highlight and shadow end of things.
In fact, I've found recoverable highlight data at 51K even!
Which was rather hard to beleive.


Last edited by JohnBee; 10-28-2010 at 02:31 PM.
10-28-2010, 02:22 PM   #24
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I didn't actually expect you to, lol. It was more a rhetorical, food for thought question.

*1500th post* I need to get out more.
10-28-2010, 02:49 PM   #25
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I am new here, so hi all Now, one quick question. If the difference in sensitivity is factor of 16, why difference in exposure time is only times 10? Was the lighting different, or was one (or two...) of the photos corrected for the exposure offline, or is there something funny here with real vs nominal sensitivity value? I had similar observation for the other samples posted here:
https://www.pentaxforums.com/forums/pentax-dslr-discussion/119942-k-5-image-q...o-samples.html
where nominal sensitivity is different by a factor 256, but exposure time only a factor of 70.
10-28-2010, 04:11 PM   #26
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Doesn't quite work that way. The difference in ISO isn't really a factor of 16. It's a factor of 4 in both cases, as ISO stops are as follows: ...100 - 200 - 400 - 800 - 1600 - 3200 - 6400 - 12800.... Shutter speed stops are (approximately) as follows: ...2.5 - 1.3 - .6 - 1/3 - 1/6 - 1/13 - 1/25.... See how each stop is double the value of the one before it?
10-29-2010, 12:38 AM   #27
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Jodokast96, there was time of 1/1.3 sec (not 1.3 sec) reported. And yes, it is a factor of 16, which is 4 stops.
10-29-2010, 01:59 AM   #28
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QuoteOriginally posted by kopperek Quote
Jodokast96, there was time of 1/1.3 sec (not 1.3 sec) reported. And yes, it is a factor of 16, which is 4 stops.
The shutter speed on the ISO200 image is 1.3s (see EXIF data).
The shutter speed on the ISO3200 image is 1/13s (0.077s).
That is a 4 stop difference (which means the shutter was open for 16x more time)
This corresponds to the 4 stop difference in sensitivity (ISO 200 vs ISO 3200).
10-29-2010, 04:30 AM   #29
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Sorry! The note in the first post says 1/1.3 - just a typo - but I should have checked EXIF before posting. The sampels look great, by the way.
10-29-2010, 04:37 AM   #30
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QuoteOriginally posted by kopperek Quote
Sorry! The note in the first post says 1/1.3 - just a typo - but I should have checked EXIF before posting. The sampels look great, by the way.
No worries, and certainly no need to be sorry

It did say 1/1.3s in the first post and you wouldn't have had any reason to doubt that.
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