alanr0

Like others, I too got the impression that you feel there is some kind of full frame conspiracy in operation. This may be what you have personally encountered. For my part, last time I checked out ...

Sorry I was not sufficiently clear, and for confusing the issue by addressing topics you are not interested in (but others might be). Lenses are certainly scalable in the sense that if you have a ...

That is part of the reason, but not the whole story. The geometric aberrations do scale in a straightforward fashion. If you double the linear dimensions of each optical element, then you double ...

The wikipedia disambiguation page provides links to multiple definitions and usages. You have arbitrarily selected the mathematical equivalence relation , and imply that this is the only valid ...

But is it the front nodal point or the front principal point we should use? Admittedly, the two points are coincident if there is air on both sides of the lens.  This applies to most photography, ...

<snip> Good point. I would add that for close-up and macro photography, it is essential to use the working F-number , or the numerical aperture, for equivalence calculations, rather than the ...

One option is to use an adapter https://fotodioxpro.com/collections/lens-mount-adapters/pentax-q or https://www.bhphotovideo.com/c/product/896100-REG/Dot_Line_dl_0836_Nikon_F_To_Pentax.html to ...

Are you confusing Nyquist frequency with sample rate , or perhaps Nyquist rate ? Wikipedia admits some confusion in the more recent literature , but most folk in this forum adhere to the older and ...

I don't see why it shouldn't work in theory. Let's plug in some vaguely plausible numbers: Assume a 1/2.5 inch smart phone sensor (7.2 mm diagonal), 28 mm equivalent field of view and F/1.8 ...

If your subject is 1 m (distance u ) from the lens principal plane and the focal length ( f ) is 50 mm, the magnification is: f /( u-f ) = 1/19. Even with a perfect lens at a wide aperture where ...

I suspect Detail Man has not got much further. After viewing my post earlier today, he was kind enough to forward some links from 2013/2014 to me. He did note that at one time DxO had a web page ...

Hi Jack. The figures provided by DxO may be reproducible, and even useful, but I don't find the BxU paper you linked at all reassuring. There was an extensive discussion a few months ago around ...

Not quite what I said. I am using "magnification" in the accepted technical sense of image size divided by subject size, and I assume that is what you meant by 0.5x magnification. If you mean ...

The thing to remember is that the focal length of the lens does not change when you attach it to a different camera. If have a 100 mm lens with 0.5x magnification, then a subject 40 mm across will ...

Rather a vague description, but you check whether any of these look familiar: http://www.opticallimits.com/all-tests https://www.imaging-resource.com/lenses/reviews/ https://www.dxomark.com/categor ...

You are correct that the devices of interest here detect angular velocity , rather than acceleration, but it is not necessarily as straightforward as directly measuring the force or torque on a ...

You are quite correct.  I didn't bother to read my own link. Essentially I analysed the " Ignorant Monty " variant.  I won't try and argue that I thought that was what you intended.  Slippery stuff ...

Surely it is equally likely that the prize is in either Box B or Box A. The new information has simply eliminated one of the original choices (Box C). It has not made B any more likely than A. The ...

Can you clarify? F-number is focal length divided by aperture diameter. Why do you need to square? What matters here is the entrance pupil diameter of the lens, and where it is located, not the ...

Bear in mind that the Sony DSC-H2 is a 6 Mp camera with 2 μm pixel pitch. Diffraction-limited Airy disk radius at f/5.6 is roughly 3.8 μm, and stopping down to f/8 will broaden this further. It is ...