I am almost sure that the sample photos should originally be sharper, but unfortunately the tester used the Av mode and deliberately stopped down to f/8 something and thus the final pictures are now looking rather soft and blurry! Well, I suppose the tester just used to use his camera as he was using an APS-C or m4/3 camera (for most of the time probably), but however that time he wasn't! :-o
http://www.dcfever.com/cameras/viewsamples.php?set=672&picture=6095
Click on the thumbnails to view the full-size originals, the key EXIF data are also posted per picture page.
After all, it's the diffraction limit that comes into play, which is the real limiting factor of such a small sensor used in the Q (and any other DCs). So, nothing can work against the Law of Physic and the only workaround is to use the lens wider opened (and with a much faster Time value/shutter speed to cope with). Nevertheless, using a wider Av will yet be a non-issue DoF wide as it has more than enough DoF already for the small lens opening based on the small sensor size and image circle.
At the end of the day, why most Q testers won't simply use the P mode for shooting? In fact, I've noticed that the P mode of it will try to only moderately stop down the lens and thus avoiding the diffraction effect as far as possible, whilst obtaining a little bit better optical quality out of the glass.
Wednesday, September 28, 2011
Logging you in...
Comments by IntenseDebate
Subscribe to:
Post Comments (Atom)
Steven · 703 weeks ago
而且目前還有"聽聞"Q也不太能夜曝車軌之類題材,
好像也是因為光圈大小的問題...
RiceHigh 110p · 703 weeks ago
作例: http://www.photosharp.com.tw/photosharp/News10223...
Ron C · 703 weeks ago
Diffractionless optics, as far as I know, have only been made as part of research into astronomy imaging although my suspicious attitude makes me think that they’ve been used in spy satellites, etc., for some time.
RiceHigh 110p · 703 weeks ago
Ron C · 703 weeks ago
RiceHigh 110p · 703 weeks ago
Ron C · 703 weeks ago
RiceHigh 110p · 703 weeks ago
Frankly, your concept is simply not correct from the very beginning.
Ron C · 703 weeks ago
Your claim that the Q's 01 lens wide open is diffractionless is incorrect. It has diffraction, although the trouble that results is small and not a concern for image quality so it behaves as if it were diffractionless-- at least, in this context.
Diffraction is not simply caused by the edges in the optical system. Diffraction is cause by HARD edges in the optical system. If those edges are made soft, there is no diffraction.
Chris · 703 weeks ago
So you are saying that all diffraction problems could be solved by making the diaphragm edges "soft", e.g. by making them act like a gradient grey filter (becoming gradually black to the outside). Do I understand you correctly? Then I wonder why they are not already on the market.
I wonder whether that is true. Can you point out some literature on that?
Ron C · 703 weeks ago
This kind of optic may be already on the market for cameras but I don't know about it.
The only source I have at hand is the work of Dr. Rus Belikov at NASA's Ames Research Center (this is in the so-called "Silicon Valley" part of the San Francisco Bay Area). He discusses it for several minutes beginning at about 29 minutes into this video (diffractionless optics is not the main topic of the lecture): http://www.youtube.com/watch?v=g78iLwG0hvk
RiceHigh 110p · 703 weeks ago
Ron C · 703 weeks ago
Your original post is about diffraction limits and small sensors and that there's no way around diffraction. You'd obviously never even heard of diffractionless optics until I mentioned it.
I don't know how practical these would be in a normal camera and, since you've never heard of them, you don't know either.
RiceHigh 110p · 703 weeks ago
The resolution of a lens is derived by the f-number and the wavelength of light basically. It is Physics but nothing else. I don't know what you're going to argue with me. Last time back to June, I had an international technical meeting with some space experts from the NASA and the ESA. I might know nothing, but I shall ask them to learn more the next time we meet.
Ron C · 703 weeks ago
One way to think of this is that the soft edges have the effect of narrowing the beam of light so it can't become diffracted; similar to shining a narrow laser into a wide lens. There won't be diffraction because the beam didn't hit the edges. This isn't a perfect explanation but maybe it helps?
You can't use the usual formula for f/number with a lens that has soft edges because you can't measure its diameter in the usual way.
RiceHigh 110p · 703 weeks ago
But spherical aberration comes into play then, which will yet decrease resolution, anyway.