What if 36mp DSLRs were around the corner?

[BernardLanguillier]

How does one reason with another who refuses to use reason?

Bill

You are a brave man Bill, I had already given up. 

Cheers,
Bernard

[BobFisher]

Janes, it's not a matter of reasoning.  It's a matter not being able to explain yourself clearly.  You've provided no explanation of your own for why I'm wrong.  You simply point to other sources.  I don't actually know if you know what you're talking about or if you're just parroting others.  I don't know if you do any of your own work or just blindly read and accept. 

Having gone back and reviewed some information I had previously I recognise that my earlier comments were mistaken.  But it's got nothing to do with 'how digital sensors scale' or anything related specifically to digital.  It's relevant to all formats.  And it is, as I outlined earlier, related to magnification.  The laws of optics don't change.

What I was forgetting is that the additional enlargement of the smaller image doesn't fully make up for the lower magnification at the image plane. The smaller magnification at the image plane creates CoC that aren't exactly proportional to the difference in magnification.  So even though that smaller image (from a smaller sensor or a smaller film format) has to be enlarged to a greater extent, the CoC in the final image are still smaller leading to greater DOF. 

[bjanes]

Janes, it's not a matter of reasoning.  It's a matter not being able to explain yourself clearly.  You've provided no explanation of your own for why I'm wrong.  You simply point to other sources.  I don't actually know if you know what you're talking about or if you're just parroting others.  I don't know if you do any of your own work or just blindly read and accept.

Bob,

One problem with information on the internet is that one often does not know if it is reliable. Anyone can post anything. Although I do form opinions on my own, when posting I often like to back up my assertions with an authoritative source. Roger Clark has a PhD in astrophysics from MIT and works with planetary imaging for NASA. He does know what he is talking about. You might be better off if you would check out the accuracy of your statements before posting them.

Actually, you could use Dr. Clark's post to back up your original assertion. If you open up the aperture setting on your point and shoot to the same diameter (not f/number) as a dSRL or MFDB so that the same number of photons are collected and the image quality would be comparable (at least from photon counting statistics), the depth of fields would be the same.

Regards,

Bill

[BobFisher]

I didn't question Clark's knowledge.  It wasn't his article I referenced back to anyway.  The source is irrelvant.  I admitted that my memory was flawed.  So be it.  It's not a matter of 'backing up' statements.  Working from memory I thought I was correct.  I wasn't.  Fine.  Move on.