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06-29-2018, 08:46 PM   #1
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Full frame vs half frame

I'm not real sure but if I put a 150-450 tele lens on a half frame camera say a KP and then on a K1, from the same point of taking an image will I get a different level of enlargement, or is the effect like just cropping the centre out of a full frame image. Does this make sense?

06-29-2018, 09:01 PM   #2
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Hello Paul,
The KP has an APS-C sized sensor, which is 24 MP, and has a crop factor of 1.5.
The K-1 has a full frame (35mm) sized sensor which is 36 MP.
Cropping the K-1 image to APS-C dimensions will result in an image of about 15 MP, but will have the same field of view as the image from the KP.
The two cases you cite will give the same image coverage but different resolutions...i.e. the image from the KP should have more detail when pixel peeping, all other things being equal.
Hope that helps.

Cheers,
Terry
06-29-2018, 09:05 PM   #3
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The KP frame is a crop of the K-1 frame. Magnification is the same on both for a given subject distance with the same lens.


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06-29-2018, 09:17 PM - 1 Like   #4
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QuoteOriginally posted by Paul Charlier Quote
I'm not real sure but if I put a 150-450 tele lens on a half frame camera say a KP and then on a K1, from the same point of taking an image will I get a different level of enlargement, or is the effect like just cropping the centre out of a full frame image. Does this make sense?
Yes. It is just like cropping out only the centre of the full frame image. But because of the resolution of the two sensors you will get 24 MP from the KP and 15 MP from the centre of a K-1.

Regards

Chris

06-29-2018, 09:31 PM   #5
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QuoteOriginally posted by Paul Charlier Quote
I'm not real sure but if I put a 150-450 tele lens on a half frame camera say a KP and then on a K1, from the same point of taking an image will I get a different level of enlargement, or is the effect like just cropping the centre out of a full frame image. Does this make sense?
The question makes sense, but your terminology doesn't. "Half-frame" would normally mean you cut a "full frame" sensor in half, so you would end up with an 18mmx24mm object, a 3:4 object, with pixels at the same density they were on the full frame sensor, so it would be an 18mp object. In actuality, a KP sensor is 16mmx24mm, a 2:3 object {just as the "full frame" sensor is}, but the pixels are smaller, so it is a 24mp object. When you use a DA lens on the K-1, it is like taking the center of out of a standard K-1 image, but because the pixels are at lower density you end up with fewer pixels than you do with the KP.
06-29-2018, 10:00 PM   #6
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Crop sensor of 24mp will provide more detail than a straight crop on the K-1 (24mp vs. 15mp as indicated above). So you could crop more and keep more detail in the same shot but the quality of the pixels may also make this different than a simple 1:1 MP comparison - I do not have the K-1 so I cannot actually give you a direct comparison.
06-29-2018, 10:30 PM   #7
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On a similar yet different path -
How would one characterize the difference between a k-p 24mpxl jpeg and a k-1 image (with a 1.5x longer lens FL) shot using its 22-mpxl 'medium' jpeg? I would expect the k-1 to win this contest in some aspects but it isn't clear cut in my mind..
06-29-2018, 11:44 PM   #8
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QuoteOriginally posted by tduell Quote
Hello Paul,
The KP has an APS-C sized sensor, which is 24 MP, and has a crop factor of 1.5.
The K-1 has a full frame (35mm) sized sensor which is 36 MP.
Cropping the K-1 image to APS-C dimensions will result in an image of about 15 MP, but will have the same field of view as the image from the KP.
The two cases you cite will give the same image coverage but different resolutions...i.e. the image from the KP should have more detail when pixel peeping, all other things being equal.
Hope that helps.

Cheers,
Terry
Thanks Terry, that is exactly what I wanted to know.
Cheers Paul

---------- Post added 06-29-18 at 11:46 PM ----------

QuoteOriginally posted by seventhdr Quote
Yes. It is just like cropping out only the centre of the full frame image. But because of the resolution of the two sensors you will get 24 MP from the KP and 15 MP from the centre of a K-1.

Regards

Chris
Thanks Chris, that is exactly what I wanted to know. Terry said the same.
Cheers Paul

06-16-2019, 08:27 AM - 1 Like   #9
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QuoteOriginally posted by reh321 Quote
The question makes sense, but your terminology doesn't.
Actually, I never heard of APS-c until digital. The APS-c size film cameras I was familiar with were called half frames.
I'm more annoyed at 36x24 being called Full Frame. There are two categories 645 crop and 645 that are "fuller". Film was called 35mm, digital should be called 36mm... not that anyone cares what I think.

I've been overruled in the nomenclature by people who won't listen.

35mm was a supreme compromise in film days only acceptable for it's convenience. 35mm IQ was considered to be the lowest you could go and still be taken seriously. Now it's some kind of gold standard. Living too long helps you see the stupidity of these things.

At such time as someone is able to produce a 4x5 digital sensor, FF will be put back in it's place, as a tiny but convenient format.

Last edited by normhead; 06-16-2019 at 08:34 AM.
06-16-2019, 09:15 AM - 1 Like   #10
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I shoot both FF and M34rds which is considered a half frame compared to a FF due to the 2x crop factor, I suppose.

The major comparison between the two, is that the smaller sensor wastes the information/light from the image circle the larger lenses produce. Seeing as the sensor cannot see the outer parts of the image circle, it crops what could have been produced.

Picture quality: my M43rds is 20mpix and K1 crop is 15mpix there isn't any dip in quality at all, when in good light. Once light drops, it becomes a case of which sensor has the best technology.

I take a lot of pictures with the smaller sensor which nobody would be able to tell weren't taken on a FF camera.
06-16-2019, 09:21 AM   #11
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QuoteOriginally posted by normhead Quote
Actually, I never heard of APS-c until digital. The APS-c size film cameras I was familiar with were called half frames.
I'm more annoyed at 36x24 being called Full Frame. There are two categories 645 crop and 645 that are "fuller". Film was called 35mm, digital should be called 36mm... not that anyone cares what I think.

I've been overruled in the nomenclature by people who won't listen.

35mm was a supreme compromise in film days only acceptable for it's convenience. 35mm IQ was considered to be the lowest you could go and still be taken seriously. Now it's some kind of gold standard. Living too long helps you see the stupidity of these things.

At such time as someone is able to produce a 4x5 digital sensor, FF will be put back in it's place, as a tiny but convenient format.
The APS-c sensor is about the same size as the Advanced Photo System (APS) format that Kodak and other film manufacturers rolled out in the mid 1990's or so. It had some cool features, but about the time it rolled out, the world suddenly went crazy of compact 35mm cameras instead.
06-16-2019, 06:48 PM   #12
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QuoteOriginally posted by normhead Quote

35mm was a supreme compromise in film days only acceptable for it's convenience. 35mm IQ was considered to be the lowest you could go and still be taken seriously. Now it's some kind of gold standard. Living too long helps you see the stupidity of these things.

At such time as someone is able to produce a 4x5 digital sensor, FF will be put back in it's place, as a tiny but convenient format.
When I desired to move up from 35mm film to Medium Format, the first camera I bought was the twin lens 6x6 Yashicamat. It was a significant jump from 35mm. And yet I later realized that the twin lens system without interchangable lenses was the basic amateur system of its day.

On the other hand, digital 24x36 sensors can produce images close to the quality of professional Medium Format film. I still have my Mamiya RZ67. One of these days I want to do some comparison shots against the K-1. The advantage of the digital "FF" is that there is greater depth of field at a given aperture, field of view and subject distance. Not to mention the size and convenience.
06-27-2019, 12:46 PM   #13
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QuoteOriginally posted by normhead Quote
Actually, I never heard of APS-c until digital. The APS-c size film cameras I was familiar with were called half frames.
I'm more annoyed at 36x24 being called Full Frame. There are two categories 645 crop and 645 that are "fuller". Film was called 35mm, digital should be called 36mm... not that anyone cares what I think.
I wonder if the fact that the Olympus Pen series was called "half-frame" is the origin of the term "Full frame" for 135 style film and subsequent digital?

---------- Post added 06-27-19 at 03:53 PM ----------

QuoteOriginally posted by CNunez Quote
I shoot both FF and M34rds which is considered a half frame compared to a FF due to the 2x crop factor, I suppose.

The crop factor is the diagonal change and m43 is not half-frame it is smaller. If you take APSC and turn it vertical you can fit roughly two of these into the same space as a Full Frame 24x36 since each is 24x16 roughly (some variation in the actual dimensions). M43 is also not a 3:2 ratio format and so comparisons get a little wonky.
06-28-2019, 04:12 AM   #14
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QuoteOriginally posted by UncleVanya Quote
I wonder if the fact that the Olympus Pen series was called "half-frame" is the origin of the term "Full frame" for 135 style film and subsequent digital?

---------- Post added 06-27-19 at 03:53 PM ----------




The crop factor is the diagonal change and m43 is not half-frame it is smaller. If you take APSC and turn it vertical you can fit roughly two of these into the same space as a Full Frame 24x36 since each is 24x16 roughly (some variation in the actual dimensions). M43 is also not a 3:2 ratio format and so comparisons get a little wonky.

yeah I get that I'm strictly going with fov here, where there's a 2 times crop factor.
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