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10-08-2019, 01:57 PM - 1 Like   #1
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K-1 light close to medium format

Has this chart from Photonstophotos been posted before? If so my apologies. It shows K-1ii second only to medium format cameras in low light. Some amazing scores.

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10-08-2019, 02:27 PM   #2
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What exactly is being calculated here? How does the scoring work? Not that I doubt its capabilities, but seeing the KP up in the middle of any list filled with MF and FF cameras makes me wonder about what data is actually being represented.

I know about Protonstophotos and they seem to conduct a fairly comprehensive and scientific testing method, but the data I've seen in the graphs is quite difficult to parse in a way that I can visualise. How practical is it to compare cameras by numbers that that don't directly translate into a difference in perceivable image quality?
10-08-2019, 03:08 PM   #3
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I cannot answer your questions but I am sure there will be some who can. The point of posting it is the very high ranking of the K-1ii which in my experience is a very good low light camera. As you noted Photostophotos does very good work. We can always look at images but not all of us can do that kind of testing.
10-08-2019, 03:46 PM   #4
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While I agree that the K-1 / K-1 II are fantastic in low light (no other camera have I been comfortable using ISO 3200+), this list does seem to be a limited list of FF models.
For instance Nikon D850, Sony A7R Mk3 etc etc. No Pentax 645Z for that matter too.

10-08-2019, 04:30 PM   #5
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The A7Riii is on the list as is the A9 which is considered the best of the current Sonys at high ISOs. No sighting yet of the rumored A7Siii which would be their low light champ. In any case that is not the point - look where the K-1ii is! The people who put the list together are competent and were focused on the three categories listed. I find the two responses so far to be odd. If you want the details of the testing you can go to the Photonstophotos site.
10-08-2019, 06:00 PM   #6
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It doesn't seem like they tested every camera available. What surprises me is how good the 150 mp phase one is.
10-08-2019, 07:11 PM   #7
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Source?

10-08-2019, 07:26 PM   #8
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QuoteOriginally posted by MetalUndivided Quote
Source?
As already mentioned several times Photonstophotos.
10-08-2019, 07:49 PM   #9
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QuoteOriginally posted by Mikesul Quote
As already mentioned several times Photonstophotos.
Right, I was hoping for a link, but whatever.
I looked it up and I'm somewhat confused to say the least. The fact that the K-1II has double the "Low light ISO" of the original K-1 seems odd. Yes, the 1II is better at handling ISO but surely not a full stop better.
Maximum PDR figures appear to be more sensible and Pentax isn't any remarkable on that regard.
10-08-2019, 08:21 PM   #10
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Photons to Photos

See this URL. There are a bunch of charts...
10-08-2019, 08:30 PM   #11
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QuoteOriginally posted by shardulm Quote
Photons to Photos

See this URL. There are a bunch of charts...
Do we know which chart this is? I got lost trying to find it. I'd like to understand it more.

---------- Post added 10-08-19 at 11:35 PM ----------

QuoteOriginally posted by UncleVanya Quote
Do we know which chart this is? I got lost trying to find it. I'd like to understand it more.
Ok. It is the photographic dynamic range chart sorted in decending order on iso column. The Nikons and 645 are there and score higher than the k1ii on PDR column. The k1mkii does even better if you sort by the ev column.
10-08-2019, 09:10 PM - 1 Like   #12
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The low light iso metric is the point where the sensors PDR ( photo dynamic range ) reach's a value of 6.5 at a given iso value

So what the chart is saying that at one camera at iso 7736 has the same PDR of 6.5 as another camera at iso 500

This is very similar to DXO sport score. It really does not tell you anything about the low light capability of the sensor other than where the cameras iso setting falls at 6.5 PDR.

Also the data is based off of the iso setting of that particular brand of camera and does not represent measurements based on cameras being shot using the same size exposure.

For camera A at iso 6400 many be using the same size exposures as camera B at iso 3200
10-08-2019, 09:23 PM   #13
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Pentax K5-IIs outperforms Sony A9 in max PDR, even other parameters are lower. APS-C vs. FF. What it means? Maybe that K-5IIs ar low ISO is equal to Sony's flagship model for photographic dynamic range? According to curve, that is true for ISO80 (Pentax) vs ISO 100 (Sony). But things are opposite at higher ISOs.

Last edited by Medex; 10-08-2019 at 09:29 PM.
10-08-2019, 11:21 PM   #14
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The K-1ii and KP punch above their weight in DR at high ISO because of the accelerator, which seems to preserve DR better than NR applied post-processing. About the K-5ii, isn't the general consensus that the sensor was THE best 16MP sensor, at the time? It's a great camera.
10-09-2019, 03:45 AM   #15
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Dynamic range had nothing to do with sensor size (format). It's purely related to pixel quality and signal chain from that pixel to raw files. A 14bits ADC is a 14bits ADC regardless if it is used in a 1 inch sensor or a 20 inch sensor, 14bits code 14 ev of DR max. More dynamic range means less contrast in images or less refined tone transitions when the contrast is restored. Some industrial cameras have more dynamic range than our cameras, but the images produced by those industrial cam aren't good looking. Light level in nature doesn't change, 18% exposure on a linear scale allows no more than 2 stops before high lights are clipped and works most of the time. There is only 4 stops of ISO headroom before colors coding gets below jpeg quality level, regardless of the brand of camera: 14bits - 2bits(18% exposure) - 8bits per channel colors codding = 4 stops.

Last edited by biz-engineer; 10-09-2019 at 04:39 AM.
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