Originally posted by normhead That's because it's largely a useless concept... the concept that an image has to be exactly a certain way, and that one should try and emulate what one does with one system on another system ...
That's not what the concept of equivalence is used for, Norm, and you should know that by now.
It simply describes a relationship between formats, and (for example) how a certain lens will look in FOV/DOF on any format in which it shares a mount.
Understanding the concept means you will understand whether or not you personally, depending on your typical shooting, would gain anything by changing or adding formats. Simple as that - thus, very useful.
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Quote: suggests that photography is a technical medium in which it is important to exactly create a specific image and that images that aren't created exactly that way are somehow lacking. it's a very rigid way of looking at photographic systems. That is "techcraft". The assigning of non-existent technical requirements to artistic media. You can study your graphs and tables, any of which have the ability to be a complete mis-representation, and doesn't present any information you can't absorb more usefully or practically by looking through the viewfinder. Information is useless without context, and those who promote this concept of "equivalency" tend to focus on very narrow measurable criteria to the exclusion of all else, including the context in which those criteria need to be understood.
Very impressive rant, Norm!
You realize that understanding simple things like FOV, DOF, and noise and how to maximize their effectiveness within your budget are not esoteric tangents, getting in the way of your art? That understanding them actually can make the pursuit of your art easier? That it can save you time, money and headaches?
Quote: Like the social sciences, there are things you have formula for and things you don't. Being able to measure some things but not others, and some very important things, micro-contrast and it's effect on the appearance of sharpness, how the control of CA affects the appearance of sharpness etc. or deliberately leaving them out of the discussion creates a narrow discussion based on depth of field, or dynamic range etc. things that can be measured.
Microcontrast, CA, everything you mention above is independent of format and has no bearing on a discussion of the differences between formats. Not sure why you're mentioning them, other than to try to lend weight to your argument by using nice-sounding concepts and declaring them on your side
Quote: SO you have those for whom "equivalency" is not understood (in it's limited technical explanations) who look through a camera lens and examine the images and you understand perfectly without the mumbo-jumbo. Then you techies who have tried (like Psychologists) to turn a soft science into a hard science., and spend way to much time reading numbers and charts to prove things that present only part of the picture.
The folks who look through the lens and 'see' equivalence are not mutually exclusive from the ones who can describe it's simple math and physical concepts. You seem to value the first and do not value the second, but they're usually coming from the same person.
I think you 'get' equivalence very well, Norm, you just seem to get very agitated when its described in a precise way and when it can be used to give examples of occasions where it doesn't favor your current format. You should get over that.
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