Discussing Aperture equivalency (or something like that)

[Luke]

I see that you're misrepresenting everything I've said, which may or may not be deliberate on your part. The point is that serious photographers like myself and my friends are very, very well aware of sensor size and noise issues, and we don't need the "effective aperture" to confuse things.

sorry..... it certainly isn't deliberate.

 

[Luckypenguin]

I'm up to a dozen pros now asking about this, and like another person said here, it's not useful because it makes no sense at all, and because nobody references it. I've been on a lot of photo forums, and there's no track record on such a thing. Perhaps you could show where those references are on a couple of pro photo forums.

To save you from de-railing this thread any further, think of what you've been told here as like learning theory at School or University. There is science behind it, but in a practical, real world situation it may or may not make all that much of a difference.

 

[dalethorn]

sorry..... it certainly isn't deliberate.

I didn't realize it was your post, Luke - I thought it was the other guy. My apologies. My only issue is the "effective aperture" and nothing else. The only actual value I see there, outside of a laboratory, is for full-frame guys to diss smaller cameras on the basis that their apertures "really aren't" what the cameras claim they are. We do know that the focal lengths printed on most smaller camera lenses need to be translated to 135 effective values, for most users to know just how much 'zoom' or magnification they're getting with that camera. To think that someone with a small fixed-lens camera is going to do effective-aperture calculations to see how much DOF they have at a particular zoom setting between 18 and 50 mm (effective), rather than look at the image on the screen, or playing back a test shot, and/or looking through the viewfinder, seems highly dubious.

 

[dalethorn]

To save you from de-railing this thread any further, think of what you've been told here as like learning theory at School or University. There is science behind it, but in a practical, real world situation it may or may not make all that much of a difference.

'Derailing' is a false accusation, and I reject it.

 

[Amin]

This is same tiresome exchange I've been seeing on camera forums for so many years now. There is no objectively correct way of looking at this. "Equivalent" has no established meaning. "Focal length" does, and so does "aperture", but "equivalent" does not. Even "aperture" is ambiguous since some use it to mean relative aperture (f-number) and others mean physical aperture (in mm). Lots of people like to say "equivalent focal length", and a fair amount of people now like to say "equivalent aperture", making the argument that relative aperture is based on physical aperture as well as focal length, thus relative equivalent aperture being a logical extension of physical aperture and equivalent focal length. Others don't accept the term. Fine, don't accept it. But no one can tell anyone else what is right or wrong here. /end thread