DX format, pixel, sharpness question.
Oct 14, 2014 22:36:40 #
dandi
Loc: near Seattle, WA
While reading the article The Full-Frame Advantage by Ken Rockwell:
http://www.kenrockwell.com/tech/full-frame-advantage.htm
I came across this statement in Introduction section:
Small-format DX and 1.6x DSLRs were ideal for digital SLRs up to about 6MP back in the dawn of digital photography. By about 10 MP in small formats, most of the extra pixels today are splitting up the limitations of your lenses (and our own photo abilities) into smaller pieces instead of showing us more detail. Having more pixels on a small format doesn't make a sharper picture if all these extra pixels are doing is splitting up a lens' limited resolution (or subject motion or limited depth of field or small-aperture diffraction) into more pixels.
Can somebody explain to me what is he saying? And do you agree with it?
Thank you.
http://www.kenrockwell.com/tech/full-frame-advantage.htm
I came across this statement in Introduction section:
Small-format DX and 1.6x DSLRs were ideal for digital SLRs up to about 6MP back in the dawn of digital photography. By about 10 MP in small formats, most of the extra pixels today are splitting up the limitations of your lenses (and our own photo abilities) into smaller pieces instead of showing us more detail. Having more pixels on a small format doesn't make a sharper picture if all these extra pixels are doing is splitting up a lens' limited resolution (or subject motion or limited depth of field or small-aperture diffraction) into more pixels.
Can somebody explain to me what is he saying? And do you agree with it?
Thank you.
Oct 14, 2014 22:41:38 #
Basically he is telling you that high density sensors require high quality lenses to properly resolve a high quality image.
Explain KR? People have been trying to do that unsuccessfully for years! ;-) ;-)
Explain KR? People have been trying to do that unsuccessfully for years! ;-) ;-)
Oct 14, 2014 22:46:03 #
lighthouse
Loc: No Fixed Abode
What he is saying is that he knows how to market and sound as if he knows what he is talking about.
I think this introduction was already there about 6 or 7 years ago when 12.3 was considered a large megapixel number for an APSC camera .
Thats about when people started speaking with great wisdom about how they were being jammed in too tightly and it would affect performance.
Since then, very good APSC sensors have been developed with up to 23 or 17 megapixels being quite common, and being considerably "better" than those old 12.3 and 10 megapixel cameras.
I think this introduction was already there about 6 or 7 years ago when 12.3 was considered a large megapixel number for an APSC camera .
Thats about when people started speaking with great wisdom about how they were being jammed in too tightly and it would affect performance.
Since then, very good APSC sensors have been developed with up to 23 or 17 megapixels being quite common, and being considerably "better" than those old 12.3 and 10 megapixel cameras.
Oct 14, 2014 22:53:59 #
dandi wrote:
While reading the article The Full-Frame Advantag... (show quote)
All you need to do is go the DXOMARK.COM and compare any lens on cameras with different MP sensors and it will show that the higher the MP of the sensor the sharper the image.
KR blows a lot smoke.
Oct 14, 2014 22:57:02 #
lighthouse wrote:
What he is saying is that he knows how to market a... (show quote)
I believe what Rockwell is saying does not have much to do with sensor quality, but rather lens quality and their ability to resolve. He states that beyond a certain pixel density, the limitation of the optics ability to resolve is reached. I am not educated enough about optics to agree or disagree with this, but I know enough about micro-electronics to know that with enough light, a tightly packed sensor is equal to a larger sensor of the same MP size, other factors being equal.....he may have hit on the true advantage of an FX sensor, its ability to spread the optical resolution over a larger area for the same angle of view...
Oct 14, 2014 23:12:11 #
dandi
Loc: near Seattle, WA
joer wrote:
All you need to do is go the DXOMARK.COM and compare any lens on cameras with different MP sensors and it will show that the higher the MP of the sensor the sharper the image.
KR blows a lot smoke.
KR blows a lot smoke.
Actually I did some comparison on DXOMARK.COM and results didnt support what he said, thats why I was puzzled.
I have two DX cameras (10mp and 16mp) and the pictures from the camera with 16 almost always look better.
Thank you all.
Oct 14, 2014 23:12:54 #
dandi wrote:
While reading the article The Full-Frame Advantag... (show quote)
Yes, he is saying you need very high quality (resolution) lenses to realize any advantages of a high resolution sensor (MPX) - otherwise, why bother.......
Oct 14, 2014 23:16:26 #
What he is saying is that beyond 6 megs pixels on a DX size sensor the limitation is the resolution power of the lens, not the number of pixels. Its a bit like saying that using slower film (smaller grains) will not give you sharper pictures if your lens isn't sharp. Of course he wrote that seven years ago and sensor technology as well as lens technology have rendered his remarks out of date. The thread of truth is that at any technological level there is a limit to how many photo sites you can cram onto a sensor without consequent problems, like noise, moire and false colours.
Oct 14, 2014 23:17:36 #
lighthouse
Loc: No Fixed Abode
dandi wrote:
.......and results didnt support what he said, thats why I was puzzled.
.......
.......
That is very often the case, but whenever the subject comes up several someones will usually come along and tell you that KR does a wonderful job and that anyone who picks holes in him is only jealous.
I'm surprised that his apologists aren't here already in this thread.
There are people on UHH who will even make excuses for him telling bald faced lies.
Oct 14, 2014 23:31:45 #
dandi
Loc: near Seattle, WA
mcveed... The thread of truth is that at any technological level there is a limit to how many photo sites you can cram onto a sensor without consequent problems, like noise, moire and false colours.[/quote]
Now DX is 24mp. Do you think we are getting close to this limit?
Now DX is 24mp. Do you think we are getting close to this limit?
Oct 14, 2014 23:32:49 #
dandi wrote:
While reading the article The Full-Frame Advantag... (show quote)
He is alluding to the diffraction limit. The absolute ability of a lens to resolve two points is based on the aperture diameter. So for a slow lens it is possible to reach the diffraction limit at higher f-stop settings. If your beyond the defraction limit then cropping will result in some fuzziness.
My back of the envelope calculation (physicists please double check my math) tell me given an ASP-C, 12 meg-pix sensor, and a typical 35mm lens, say 105mm f5.6, we are about one order of magnitude away from the diffraction limit. So no worries about that.
However the other comments about lens quality definitely apply.
Oct 15, 2014 00:05:14 #
mcveed wrote:
What he is saying is that beyond 6 megs pixels on ... (show quote)
Another think that has advanced enormously is what they can do with the pixels they DO get from that small sensor. I bought a Nikon 1 series camera a while back and was very pleased with the output from it, even compared to my DSLR's.....I read up on the technology ised and found that they did some real magic in the software, as well as how the data was interpreted from the sensor. In short, they were able to make a small sensor behave like one much larger, by using some tricks of software and speedy processing onboard. As a result, the pictures were much better than one would expect.
From this, I would interpolate that what is being done now in the larger cameras is much superior to what was being done even 5 years ago...
Oct 15, 2014 00:14:21 #
dandi wrote:
While reading the article The Full-Frame Advantag... (show quote)
Nobody can explain what someone is saying when that someone is speaking PHOTOBABBLE. I question 10% of what he says and disagree with the rest.
Oct 15, 2014 00:38:35 #
Mogul wrote:
Nobody can explain what someone is saying when that someone is speaking PHOTOBABBLE. I question 10% of what he says and disagree with the rest.
LOL! Photobabble.. :lol: :lol:
Reminds me of "Word Salad" people would spin with lots of oil and vinegar.
My camera is rated at 24.5 MPX. That is a huge pile to cram on a hard drive.
The D800 are up to 36 MPX. Hugier piles of files.
I know, I know, not every picture approaches the rating. Thank Goodness.
But the denser the photograph, the better it can be enlarged or worked with.
Much better than the Casio digital I was trying to get pictures with for my web sites of the early/mid 1990's.
Those were Grainy days.
Certainly not so now.
Did you remember to contribute? :lol:
Oct 15, 2014 00:52:47 #
SonnyE wrote:
Those were Grainy days.
grain? Grain? GRAIN?
People don't know what grain is until they've tried to push Tri-X 3 stops! 8-) 8-) 8-)
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