The shots were framed as closely as I could manually adjust my footsteps and ball head/tripod. I would say the frames are within 1" of each other in all ways.

"dwdallam; what you observe is how it is, but your own description of what you see is at best imprecise,"

And I think I've admitted that three or more times now.

Do you have any new information to add? If so, please share it.

Why do you think one person's comments represent the entire web forum community? It's a fallacy called "Specific to the General." I get your point, but don't let one person run you off (operative word being "one").

I don't even know what the argument is.

If this statement is wrong, then we need a discussion. If it is right, then we've concluded what I set out to question, and we need a new thread on the physics of DoF regarding photography:

"Using a longer length lens will give a greater illusion of a blurry background when compared to a shorter lens and all things aperture, distance to subject, frame fill, and print size are equal."

I think the statement is wrong in relation to DOF. And as I've said a number of times, the physics, charts, equations and what not don't really matter in this discussion. That is because we are comparing two situations where we (you) have minimised the differences between the two situations, to just the variables we are comparing. It seems to be the almost perfect experiment, where we don't have to bother with equations. In addition to all this, equations really don't matter anyway. And the reason for this is that ultimately the only important thing for DOF determination is the eyes. Once again for Tony et al, DOF is a visual perceptual phenomenon. If you see acceptable sharpness, then the image IS acceptably sharp. No amount of fussing over the FOV or level of blurriness in the background will change this fact. If you can see it with your eyes, then it is real. And I (and most others too) can see that DOF is larger with shorter focal length lenses (when all else that is important is equal).

I'm glad you realise that, and decided put it in your introduction, but that still leaves the question why you bothered to post it.


Yes, I do, which should be clear from the part of the post which you didn't bother to read. You seem to obsessed with insulting other people.

However, perspective doesn't change as unevenly as illustrated in dwdallam's shots, if that's what you're implying.


Here's a mirror. Please make use of it and guess three times why the tone of my post was such, and why I thought it funny to read your own, condescending "surgery" remark, while missing what's right there in front of your own two eyes. Perhaps that's condescending, I thought it witty when I wrote it. I'm sorry that I insulted you then.



I don't know where that 1" is - on your screen, in the full resolution image on your screen, but the point here was that ridiculing others for needing eye surgery when they themselves don't even bother looking at the examples you posted is slightly less than clever.

What you did was fine enough; it illustrated what you wanted to ask about.


Yes, but please continue reading past the point which you quoted. It seemed, from your then-currently last post on the topic, that you still struggled with an apparent disconnect between what you saw and how the DoF "should" work according to physics.

I was trying to contribute by telling you that there isn't such a disconnect.

To be honest, I don't know why I am replying to this dribble, but here goes.



So you're implying that he is lying then?? This seems to be the same type of response I used to get from the kooky old film guys when I presented evidence to them about sensor linearity.



1. You're rude?
2. You have no idea?
3. You have nothing to contribute to the discussion?

How did I do?

Why don't you actually contribute something to this discussion and address some of the entirely valid and useful points myself and others have made from our side of the discussion? Or just throw more insults around. You decide.

I haven't read this whole thread, but unfortunately it seems to have degenerated into a rude pissing contest.

It's therefore now closed.

Michael