APS-C Sensors And Telephoto Lenses

tb1891 wrote in post #12530160
I'm failing to see how that's any excuse to be an ******* to someone for no reason.

That's just how the internet is. You'll only frustrate yourself if you try to police it.

tb1891 wrote in post #12530160
I'm failing to see how that's any excuse to be an ******* to someone for no reason.

It isn't. There's no excuse at all.

It's very difficult to detect "tongue inserted in cheek" on here but maybe I should have been a bit more obvious.

Incidentally, that would be ******** in UK English. Thought you'd like to know.

JohnB57 wrote in post #12529969
A bit brutal but hey. Tough frontier country up there though. They say it like it is...

True however. The important thing here is that we have a "system" with compatible, but varied, technology and there has to be a reference, in this case 35mm/FF. It's not difficult to understand and as stated above, if you can't grasp why the manufacturers quote the equivalent, maybe it's time for a holiday in Seattle.

No soap boxes here - I'm simply curious.

Is there a line someplace?

If you have problems fully getting your arms around a concept on the left side of the line, folks will be helpful. But if what you feel like asking about is on the right hand side of the line, the d####bags are going to come out and try to belittle you.

Again ... jes wunderin.

JohnB57 wrote in post #12530260
It isn't. There's no excuse at all.

It's very difficult to detect "tongue inserted in cheek" on here but maybe I should have been a bit more obvious.

Ok. I missed that.

I'll put my d####bag t-shirt back on.

James Emory wrote in post #12528928
Why do manufacturers state for example; 400mm lens, equivalent to 640mm on a APS-C sensor camera. Seems to me that a 400mm is a 400mm no matter what sensor is used. An APS-C sensor is not going to bring the subject any closer than it would on a full frame sensor. The field of view might appear that way but the subject isn't 1.6 times closer. Am I missing something here?

Dead on; you've got the proper grasp of the situation

TeamSpeed wrote in post #12529358
They state it that way because it appears that most people have an easier time understanding the incorrect statement and what impact it seems to have to them, than what the actual technical effects really are...

And a dead on answer to the first half of your question. It's a short-handed way of explaining the difference and making the product SOUND more impressive; at the expense of continuing to pass bad (or at the very least, very marginally useful) info into the community.

RandyS wrote in post #12530544
No soap boxes here - I'm simply curious.

Is there a line someplace?

If you have problems fully getting your arms around a concept on the left side of the line, folks will be helpful. But if what you feel like asking about is on the right hand side of the line, the d####bags are going to come out and try to belittle you.

Again ... jes wunderin.

Yup. You're right. And whatever you do, DON'T ask a question that was posted previously or the thread police'll point you toward the "search" function and lambast you for wasting THEIR time 'cos they absolutely HAD to read and reply to your post or they'd burn.

Still trying to work out d####bags... It's not like "d###bags" with a 112.5% crop factor is it?

man, people get offended too easily.

JohnB57 wrote in post #12530637
...

Still trying to work out d####bags... It's not like "d###bags" with a 112.5% crop factor is it?

Sorry, but ...

gosundevils wrote in post #12530653
man, people get offended too easily.

Tongue still in cheek...

I feel like this is necessary...

If manufacturers didn't state 35mm equiv field of views then trying to figure out the sort of lens you're getting with all the P&S cameras would be a pain in the a*se process of checking sensor sizes and doing calculations.

As for it "not going to bring the subject any closer", well I guess that depends on how you define "bring the subject closer". But if you take a 30mm lens and put it on a 35mm camera, take a shot, then take a shot from the long end of a Canon G12 (30.5mm) and I assure you most people would call that "bringing the subject closer".

black holes do not destroy information

arentol wrote in post #12529844
Yes, you are missing something. You appear to believe that major lens manufacturing companies like Canon, Sigma, Nikon, Zeiss, etc are all so stupid that they think that the focal length of a lens actually changes based on camera sensor size. Since this is of course an intensely absurd belief what you are really doing is revealing your own mental limitations.

All the manufacturers are doing is providing you factually correct information to assist with your purchasing and use decisions. When a 400mm lens is used on a Canon APS-C camera the AOV is equivalent to what you would see if you used a 640mm lens on a 35mm camera. That is in fact the case, and that is all they are saying with their equivalency statement. So the statement is accurate, correct, useful, and does not in any way indicate that the manufacturer actually thinks that the lens focal length is magically changed by your sensor size. The big clue to reveal this fact is that they use some variation of the word "equivalent", and also the fact that anyone actually capable of calculating the focal length of the lens they have built is not possibly going to be so stupid as to think the lens focal length changes with sensor size.

If you read my post again, does it appear that I do believe this, just asked why do.........

It has nothing to do with the size of the sensor, it's all about pixel density. If you take a FF sensor and an APS - C sensor with the same pixel density and same quality of pixel you can crop an identical quality/resolution 1.6 sized image out of the center of the FF file. No reach advantage what so ever. I believe that was the case back when the 20D was the current 1.6 crop and the 1Ds2 was the current FF sensor, they both had identical pixel size / density.

Of course a FF sensor with the pixel density of the current 7D/60 would be around 47 mp so there will probably continue to be a true reach advantage with the 1.6X croppers.