[rawr]

Hi all.

What do you suppose the K7's high ISO performance will be like?

I'm curious since the high-ISO of the K20D and K200D (my current digital Pentax) is OK but not great, and this is proving to be a real obstacle to the kind of photography I like to do (street/ night/ nature).

I can work around current high ISO limitations with good camera craft, fast lenses, PP etc but quality high ISO performance gives valuable headroom.

From the DXOMark.com stats I've compiled a chart (see below) showing the relative performance of these Pentaxes visavis other APS-C sensors and current full-frame DSLR's. So far the Nikon D90 leads the APS-C pack and I must admit I am looking quite closely at it at the moment as a potential future upgrade..

I'd like the K7 to give the D90 a run for it's money in terms of high ISO, because I like everything else about the K7 and Pentax.

Does the K7 do high ISO significantly better than for eg the K20, or indeed up to the standard of the D90?

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Last edited by rawr; 06-17-2009 at 02:38 AM. Reason: updated score for 50d, added KM

[and]

it will not be significantly better.
It is an APS-C sensor with 14.6 megapixels, you cannot really get around that.
When it competes for instance with the nikon d700, that sensor is twice as big and has only 12 megapixels, thats a big difference.

[Pentaxor]

lowlights are really a problem eversince. you need to open your shutter a lil bit longer and shoot overnight if you have to, if you really want that exposure that you are looking for.

[rawr]

it will not be significantly better.
It is an APS-C sensor with 14.6 megapixels, you cannot really get around that.
When it competes for instance with the nikon d700, that sensor is twice as big and has only 12 megapixels, thats a big difference.

True. APS-C is never going to catch full-frame (and above). But there seems lots of scope for improvement just within the APS-C space. Narrowing the gap between the D90/D5000 and the K20 for example should be something for Pentax to target with the K7's sensor and firmware.

[asdf]

I think most of us are interested in signal-to-noise ratios measured in dB:

(click on SNR 18%)

K20D

D300

(An interesting observation is that the Pentax K20D can achieve a higher signal-to-noise ratio than D300, at the lowest ISO (not really 100!). )

[rawr]

Yes, the K20D vs D90 comparisons are also interesting. On SNR and everything else the D90 is noticeably ahead.

One hopes the Pentax /Samsung engineers have been able to work some improvements into the circuitry to ensure the K7 improves on the performance of K20D relative to its APS-C competitors.

DXOMark K20 VS D90 comparisons page

[and]

True. APS-C is never going to catch full-frame (and above). But there seems lots of scope for improvement just within the APS-C space. Narrowing the gap between the D90/D5000 and the K20 for example should be something for Pentax to target with the K7's sensor and firmware.

true, technology can improve, although in the case of the d90, it also has slightly fewer megapixels. So imo the difference would likely be larger if pentax made a 10mpix version of their current sensor, than slightly improving the noise characteristics of it and keeping the same amount of megapixels.

[ogl]

Hi all.


I'd like the K7 to give the D90 a run for it's money in terms of high ISO, because I like everything else about the K7 and Pentax.

Does the K7 do high ISO significantly better than for eg the K20, or indeed up to the standard of the D90?

K20D has NR OFF as default, N/C - ON.

A900 is fantastic camera, not noise generator.

[ogl]

In "ISO Sensivity"
I've found funny measurements:
D300 manufacturer ISO1600 = real ISO1145.
K20D manufacturer ISO1600 = ISO1382.

D300 ISO800 = 571. pentax = 682.
D300 ISO400 = 288. pentax = 339.
D300 ISO3200 = 2063. pentax = 2676.
D300 ISO6400 = 4898. pentax = 5357.

Pentax is closer to real ISO.

P.S.
D90 ISO1600 = 1125
K20D ISO1600 = 1382

D90 ISO6400 = 4438
K20D ISO6400 = 5357

Almost 1000 units lower.

[ogl]

Low-Light ISO score for the Canon EOS 50D is being corrected from 834 to 696

50D
3200 = 2342
1600 = 1172
800 = 618
400 = 306

[asdf]

In "ISO Sensivity"
I've found funny measurements:
D300 manufacturer ISO1600 = real ISO1145.
K20D manufacturer ISO1600 = ISO1382.

D300 ISO800 = 571. pentax = 682.
D300 ISO400 = 288. pentax = 339.
D300 ISO3200 = 2063. pentax = 2676.
D300 ISO6400 = 4898. pentax = 5357.

Pentax is closer to real ISO.

P.S.
D90 ISO1600 = 1125
K20D ISO1600 = 1382

D90 ISO6400 = 4438
K20D ISO6400 = 5357

Almost 1000 units lower.

Sounds like a bit of false advertising.

[Unlocker]

Instead of looking at graphs, I would look at photographs!

How noise looks is subjective, whilst another camera may have a higher score, you may prefer the look of another.

As an example, have a look at these. Hoping to do full crops etc if I get final firmware before the camera goes back on saturday.

[asdf]

Instead of looking at graphs, I would look at photographs!

The interesting thing about these graphs is that when you look at the EXIF of a photograph, someone's pulling your leg. The advertised ISO may not be so.

[ftpaddict]

The D90 and D5000 do so well because of heavy-handed noise reduction. I prefer a little grain in my photos.

[rawr]

The interesting thing about these graphs is that when you look at the EXIF of a photograph, someone's pulling your leg. The advertised ISO may not be so.

Indeed. Probably varies from camera to camera too, as well as temperature, maybe even battery state. But probably not by much hopefully. At least the dxomark tests are probably within a standardised environment.

So many variables to evaluate. My head is spinning.