Apature

[tim11]

(SNIP)
You will note that not one blurb here (or anyplace else) mentions any foolishness about the aperture “Changing” due to this or that permutation or action like zooming. (SNIP)

Foolishness? Those are very basic blurbs that writers assume anyone with a camera (and a suggestion of logic) will realise once they have a camera in their hands. And you don't know they do change? That shows what rubbish photography teacher you are. Please don't teach your kids, if you have any.

You seem to know something about Av.. that's good. Now for the next lesson go to Lens Specifications Explained

For your benefit, I quote here right from the bottom line:
"EF 100-400 F/4.5-5.6L IS USM : An Electronic Focus lens with a telephoto zoom range from 100 to 400mm, with a maximum aperture of f/4.5 at the short (100mm) end and f/5.6 at the long (400mm) end."

[tim11]

---Razr is obviously not the professional photographer he claims he is and all he does for this site is create unrest and confuse newbies.

It's for this reason I keep going... .... However,,,, I admit this forum has been too quiet.

[Nickcanada]

This is the most fun I've had in while. It is starting to get boring now though. I think we are coming at Razr in too many directions. Lets focus our questions to just one and do not get side tracked from the one question. Do not talk theory.

Simple question..... It's been asked before........


Razr

Put the camera on a tripod

Take a variable aperture lens,

put it in M mode

Select the largest aperture you can, that is the smallest F # (1.4 is a larger aperture opening then 2.8, get it?)

select the widest focal length (if you have a 17-70mm lens 17mm is the widest)

take a picture

Now take the zoom ring and twist it until you reach the longest focal length (that would be 70mm on a 17-70mm lens)

Did the aperture value change? Did the F # change? Report your findings please!

IF you still don't believe take a picture now while you are at the long end of the lens, your camera is on a tripod so it should not have moved!

Review the two photos! is one darker then the other? I'm willing to bet the one at the longer focal length is darker. Why? Because the aperture value has changed!


Please do not respond or converse with Razr until he completes his homework! We must work together folks!


P.S. Did I mention I was having fun!

[tim11]

This is the most fun I've had in while. It is starting to get boring now though. ----!

Now that his answers are predictable.. yeah... it's getting boring. Expect more Av blurbs. I don't mind reading lens spec for a change though.

Maybe Jeff should hire someone once in a while like our Professor Razr here to add some spice to this forum. It's been almost in coma state for quite a while now...

[TenD]

Razr all of your quotes give a great explanation of Aperture Priority, but many of them support what the entire board (except you) say. The key point you are missing is OVER THE AVAILABLE RANGE. A variable aperture lens ie. f/3.5-5.6 cannot support a constant aperture of f/3.5 and when zoomed in f/5.6 is all the lens can physically support.

Even if you had an old fashioned "dip and dunk" lens with an aperture ring the amount of light entering the lens would be equal to a smaller f/number when zoomed, no matter that the aperture ring is set to the largest aperture. The opening is only so big and only so much light can enter the lens.

I can't understand why you won't simply take a variable aperture lens and put it on your body, set the maximum aperture, zoom it in, and out and watch your aperture change to the maximum aperture available. The opening may not change, but the maximum amount of light will, effectively changing your maximum aperture. The newer AF electronic lenses transmit this to the body and the f/number changes to reflect this, physically the opening probably doesn't change, but the effective light entering the camera most certainly does.

[JTL]

Warning to all:

Razr's position is designed to try to people banned from the site.

He was recently temporally banned for his egregious behavior. This thread is his revenge.

Jeff Keller had the nerve to send me an email for "insulting" Razr when all I did was ask that he back up his b.s... and I got an "Infraction Point" charged against me. Did this happen to anyone else?

I've contributed money to this site in the past when Jeff was looking to do an upgrade and I'll tell you all this, it's a sad day when an out-of-control troll can get away with this sort of thing and long-time contributors are punished for trying to make sure GARBAGE INFORMATION doesn't get passed and challenging the purveyors of garbage.

Jeff Keller...unless you want this site to implode, open your eyes.

Maybe Jeff should hire someone once in a while like our Professor Razr here to add some spice to this forum. It's been almost in coma state for quite a while now...

If more contributors than I got that insulting email form Jeff Keller, this place is danger of being a lot more comatose...I'm sure no one will take kindly to it. He's in danger of only being left with Razr at the end of this.

[JTL]

None of the articles posted by Razr support his view. In fact, some of them even support the view expressed by all of us.

There is no "view" by all of us...there is only FACT. He is wrong. There is no debate.

I can't understand why you won't simply take a variable aperture lens and put it on your body, set the maximum aperture, zoom it in, and out and watch your aperture change to the maximum aperture available. The opening may not change, but the maximum amount of light will, effectively changing your maximum aperture. The newer AF electronic lenses transmit this to the body and the f/number changes to reflect this, physically the opening probably doesn't change, but the effective light entering the camera most certainly does.

Razr does not test for himself because either:

1. He doesn't actually own a camera and lens to test with

2. The postion he is taking is just to get people riled up and he actually does know the difference....but I doubt it highly.

[BBPhoto]

OK, I am convinced. Razr either does not own an SLR, owns an SLR with no lenses or is simply trying to make trouble here. I asked a very clear and concise question and like with so many others, his goal was to evade all common sense and avoid answering.

My suggestion to everyone is that we drop this. It's not worth the time or the trouble and it's unbecoming to see such an important part of the active DCRP community get dragged into this nonsense by someone who wouldn't appreciate the help even if he were willing or able to understand it.

JTL - I did not receive such an email from Jeff but I haven't been as active in this thread as yourself. One thing that I learned from my years working for someone else is that no matter how wrong the guy in charge is, he can still make your life miserable. Just drop it. You have more than made your point and you are absolutely right so it's not worth pursuing. I have never had any direct contact with Jeff but I would hope that he would have the ability to see what is going on here and LOCK THE THREAD rather than start slapping people on the wrist.

[Nickcanada]

How come I never get emails!!!! I want to get banned too! I feel like I'm missing out.

[David Metsky]

Never argue with a fool; people may not be able to tell the difference.