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12-13-2013, 06:15 PM   #1
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K-3 magic.....

So one off the advantages for the larger pixelcount on the sensor from the K-3 is that you can crop_crop_crop. Crop till you dropp.

So I went to a soccergame, wich I thought that the light situation was really bad. Turned out that they had installed some new light since the last time I was there. Not so bad afterall. So I only took K-3 with FA*85mm on it with me. This was a game for wich I only needed a few images for display. Only spend part off the first half off the game on taking some images. The rest was planned for some talking to people and arranging some things.

The image:


So this is a crop from the image, with nothing important in the rest off the image. The width is 3417 pixels and 2272 pixels height.

In this way:
  1. The K-3 turns instantley in a 7,76 megapixel Nikon 1 series camera.
  2. The FA*85mm turns into a wonderfull FA*150mm/f1.4 lens.

In this light and the f1.8 the purple ring on the white shirt is very prominent, but I would normaly make this one in black-and-white. Pretty cool I think!

12-13-2013, 06:23 PM   #2
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QuoteOriginally posted by RonHendriks1966 Quote
So one off the advantages for the larger pixelcount on the sensor from the K-3 is that you can crop_crop_crop. Crop till you dropp.

So I went to a soccergame, wich I thought that the light situation was really bad. Turned out that they had installed some new light since the last time I was there. Not so bad afterall. So I only took K-3 with FA*85mm on it with me. This was a game for wich I only needed a few images for display. Only spend part off the first half off the game on taking some images. The rest was planned for some talking to people and arranging some things.

The image:


So this is a crop from the image, with nothing important in the rest off the image. The width is 3417 pixels and 2272 pixels height.

In this way:
  1. The K-3 turns instantley in a 7,76 megapixel Nikon 1 series camera.
  2. The FA*85mm turns into a wonderfull FA*150mm/f1.4 lens.

In this light and the f1.8 the purple ring on the white shirt is very prominent, but I would normaly make this one in black-and-white. Pretty cool I think!
Yes, pretty cool indeed!
12-13-2013, 06:36 PM   #3
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great image,
yes cropping ability is really incredible, I rediscovered my ,not too much used till now, DA*200.
12-13-2013, 07:23 PM   #4
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NIce work as usual Ron but there's some obvious PF in that 1st shot and LGCA (green edges on rear OOF components). I wonder if Pentax are ever going to upgrade their designs to counter that?

12-13-2013, 07:45 PM   #5
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hmmmm… do you think that detracts from the image?
And how correctable is that?

I've never seen a chart on this lens, so I'm unfamiliar with how bad the CA is compared to offerings from other companies, given that I've never seen a lens with no CA, and the K-3 has a small pixel that tends to amplify such things. My understanding is CA is measured in part by it's relationship to pixel width, so as the pixels get smaller the numbers get worse. So my guess is, if they do correct it, it isn't going to be cheap. Looking at the glass recommended for a D800, the K-3 would need better. Who's going to buy that?
12-13-2013, 07:55 PM - 1 Like   #6
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QuoteOriginally posted by bossa Quote
there's some obvious PF in that 1st shot
Ron noted that himself in his comment. It's a quick adjust in LR, IMHO.

Film-era designs like the 85, and the current 31/43/77, seem prone to CA, esp wide open. Maybe the current 'trinity' are next in line for the new HD coating and 'red ring' treatment.
12-13-2013, 10:25 PM   #7
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QuoteOriginally posted by RonHendriks1966 Quote
So one off the advantages for the larger pixelcount on the sensor from the K-3 is that you can crop_crop_crop. Crop till you dropp.

So I went to a soccergame, wich I thought that the light situation was really bad. Turned out that they had installed some new light since the last time I was there. Not so bad afterall. So I only took K-3 with FA*85mm on it with me. This was a game for wich I only needed a few images for display. Only spend part off the first half off the game on taking some images. The rest was planned for some talking to people and arranging some things.

The image:


So this is a crop from the image, with nothing important in the rest off the image. The width is 3417 pixels and 2272 pixels height.

In this way:
  1. The K-3 turns instantley in a 7,76 megapixel Nikon 1 series camera.
  2. The FA*85mm turns into a wonderfull FA*150mm/f1.4 lens.

In this light and the f1.8 the purple ring on the white shirt is very prominent, but I would normaly make this one in black-and-white. Pretty cool I think!
Swan Lake as I've never seen it!

Last edited by Brooke Meyer; 12-13-2013 at 10:26 PM. Reason: Spelling correction
12-14-2013, 03:31 AM   #8
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Nice. But if you crop so that the 85mm/1.4 becomes equivalent to an 150mm lens, it will have an equivalent aperture of about f/2.4, not f/1.4.

I am curious about your thoughts on the high-ISO noise performance of the K-3 versus the K-5 though.

12-14-2013, 04:01 AM   #9
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QuoteOriginally posted by starbase218 Quote
Nice. But if you crop so that the 85mm/1.4 becomes equivalent to an 150mm lens, it will have an equivalent aperture of about f/2.4, not f/1.4.

I am curious about your thoughts on the high-ISO noise performance of the K-3 versus the K-5 though.
The lens is Always f1.4 (but in this case set to f1.8) only the DOF changes, as is with de Nikon 1 series.

So in this scene it's like 230mm/f4.9 equivalent full frame lens DOF!
12-14-2013, 06:44 AM   #10
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QuoteOriginally posted by RonHendriks1966 Quote
The lens is Always f1.4 (but in this case set to f1.8) only the DOF changes, as is with de Nikon 1 series.
It's not just the DOF, but also the noise. Crops will show more noise relative to the size of the photo. This is more or less equivalent to having to increase the ISO when you would shoot with that 150mm f/2.4 lens, at least as long as the 24MP resolution holds out.

QuoteOriginally posted by RonHendriks1966 Quote
So in this scene it's like 230mm/f4.9 equivalent full frame lens DOF!
Yes, both in DOF and in noise.
12-14-2013, 07:16 AM   #11
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I am sorry but I my understanding of the parameters that affect dof must be limited. Can someone explain why the dof changes when an image is cropped?
12-14-2013, 07:38 AM   #12
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QuoteOriginally posted by starbase218 Quote
It's not just the DOF, but also the noise. Crops will show more noise relative to the size of the photo. This is more or less equivalent to having to increase the ISO when you would shoot with that 150mm f/2.4 lens, at least as long as the 24MP resolution holds out.
Offcourse that why small sensors do perform to a lesser level then the bigger sensors. When going down to only using the Nikon 1 series sensor size inside the K-3 you also end up with the sensor performance to that new smaller size.

http://www.dxomark.com/Cameras/Compare/Side-by-side/Pentax-K-3-versus-Nikon-1-S1___914_853
But maybe, comparing to the sensor performance off the Olympus OM-D E-M1 would be better, but then again that sensor is bigger then the sensorsize off the 1 series.

But the advantage is to have that option. Hi-iso performance goes down the drain very fast, but for that I took the superfast FA*85mm with me.

QuoteOriginally posted by everydaylife Quote
I am sorry but I my understanding of the parameters that affect dof must be limited. Can someone explain why the dof changes when an image is cropped?
The Field Of View (FOV) changes with the use off the smaller size off the sensor when the attached lens keeps the same. So the FA*85mm lens has a different angle of viewing the scene on a Full Frame camera (like Sony Alpha 7) then on the crop aps-c sized K-3 or like in this case again different on the only 1 inch used sensorsize that is the same as in the Nikon 1 series. With that change the lightgatering off the lens keeps the same, but the Depth Of Field does change with the different FOV.

So the FA*85mm/f1.4
  • On Full Frame: 85mm/f1.4 for FOV and DOF.
  • On APS-C: 130mm/f2.1 equivalence to Full Frame FOV and DOF.
  • on Nikon 1 series: 230mm/f3,8 equivalence to Full Frame FOV and DOF.
It is not the lens that changes, but the use off the gathered light that changes.

So to come back on my image that was taken with the settings 85mm; f1.8; 1/320th and iso800! So I could have taken my Sigma 70-200mm lens with me (or for those who have the Pentax DA*200mm/f2.8) and use that lens on the long end. For both lenses Sigma and DA*200mm it is wise to use the f3.2 as minimum, since it is better performing then on the starting f2.8 (as is with the FA*85mm that is better performing on f1.8 then on f1.4). So that means that I would use a larger part on my sensor, but hat to crack up the iso to iso 2500 or 3200 (since I underexposed a little, but repairing with hi iso is more difficult). That would give simular image quality I guess with a little less DOF, but probably not noticable. Remember I was expecting half the light that I got for the image, that's why I didn't bring my Sigma-lens.

Last edited by RonHendriks1966; 12-14-2013 at 07:44 AM.
12-14-2013, 07:47 AM   #13
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QuoteOriginally posted by RonHendriks1966 Quote
Offcourse that why small sensors do perform to a lesser level then the bigger sensors. When going down to only using the Nikon 1 series sensor size inside the K-3 you also end up with the sensor performance to that new smaller size.

http://www.dxomark.com/Cameras/Compare/Side-by-side/Pentax-K-3-versus-Nikon-1-S1___914_853

But the advantage is to have that option. Hi-iso performance goes down the drain very fast, but for that I took the superfast FA*85mm with me.
Yup, that's true. And it seems the 24MP holds out very nicely (which was your point). Also, I think the sensor performs very admirably, given the ISO 2500 equivalence.
12-14-2013, 07:56 AM   #14
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QuoteOriginally posted by starbase218 Quote
Nice. But if you crop so that the 85mm/1.4 becomes equivalent to an 150mm lens, it will have an equivalent aperture of about f/2.4, not f/1.4
Is that against the law or something?
12-14-2013, 08:00 AM   #15
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QuoteOriginally posted by normhead Quote
Is that against the law or something?
Yes it is, the lens will keep catching photon's like every other f1.4 lens, but the smaller sensor will use less off those photon's!
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