Zooms!......why?

boyfalldown said:
I think many Canon bodies switch AF off and won't even try to AF when max aperture is below f5.6. I guess this is what he's refering to
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But I think he was referring to lenses stopped down to f8.

"but you would not want to keep a lens stopped down to f8 on the camera as you would not see much in the viewfinder and the auto-focus would give up unless you had a 1Dmk3 (or similar????)"
 
there is also this obsession with 'sharpness' in glass, partly as a justification to buy new toys. In reality, yes, some lenses are genuinely not too great, but the rest are largely perfectly good enough, and a LOT of the time, there is no real need for this 'perfect' sharpness that people seem to lust over, if you are yuri arcurs, then yes, I can understand his need for 'perfect' images, everyone else, no...the content of your shot is far more to worry about than what a 100% crop looks like... chances are most photos don't get printed huge anyway, and even if they do, you don't put your eye 2" from the print, you look at the pretty sunset or whatever is in the photo.

A slightly less 'sharp' lens according to ken rockwell or some guy in a basement with a test chart, vs not getting the shot...I sure know which I'd pick...
 
"...the rest are largely perfectly good enough, and a LOT of the time, there is no real need for this 'perfect' sharpness that people seem to lust over..."

Yup. You talk a lot of sense there but will anyone hear you?...
 
a deluded Leica wannabe
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I like deluded! :)

there is no real need for this 'perfect' sharpness that people seem to lust over
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Couldn't agree more, the sharpness debate is largely a red herring. Arguably many modern lenses are too sharp, and a little softness can be a good thing. Nearly all pro lenses by the likes of Nikon and Canon are sharp enough pretty much at any aperture.

The choice between zooms and primes should be decided on other grounds.
 
With a genuine F8 lens (as opposed to an f1.8 lens that shuts down for the split second that the shutter is open), the viewfinder will have 1/16th of the light that would be available using an F2 lens that is logically stopped down to F8.

Therefore, during composition and focusing, the F2 (or F1.8) lens has the advantage of more light being availble to see by.

If you want an easy demonstration - take your 18-55mm f3.5-f5.6 kit lens and look through the viewfinder and then compare to what you see when you use the 50mm f1.8. Best done in a dimly lit room where light is poor to start with.

With the nifty fifty, the viewfinder is 8 times brighter.

Or for even more obvious solution, press the depth of field preview button when logically stopped down to f8. This will force the lens to physically stop down (shut the aperture) and the viewfinder darkens.
 
With the nifty fifty, the viewfinder is 8 times brighter.
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With modern SLR's - certainly true of Nikon and, I think it is of Canon too - there is a maximum aperture where the viewfinder doesn't get any brighter when you widen the aperture. With Nikon it seems to be around f2.5.

To check, if you have say an f1.4 lens, try this: set it to f8 and press the depth of field preview button, and the viewfinder will darken. But set it to f2.5 and press the DOF preview and there will be no change in the brightness of the viewfinder image.
 
I think this has lost its focus. Putting it bluntly (and my neck out there yet again) I think it has something to do with the little knowledge of some users. It would seem that they are getting many a factor confuffled in their head making incorrect statements. Some of the forum knowledgeable have replied with the answer, quite simple. Too many other variables have been stirred into the mix and caused too much confusion.

Suggest some research?
 
Crofts said:
With modern SLR's - certainly true of Nikon and, I think it is of Canon too - there is a maximum aperture where the viewfinder doesn't get any brighter when you widen the aperture. With Nikon it seems to be around f2.5.

To check, if you have say an f1.4 lens, try this: set it to f8 and press the depth of field preview button, and the viewfinder will darken. But set it to f2.5 and press the DOF preview and there will be no change in the brightness of the viewfinder image.
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i have a feeling this might be because in the day when you do it your eye is adjusting so it doesn't get too bright, try it in a dimly lit area and the f/1.4 lens will be a lot brighter than the f/2.8 one
 
cherokee1111 said:
heres an example -maybe a bad one - of a prime...the nifty fifty 1.8 is tack sharp at f4-f8 but at f1.8 its soft so whats the point of the f1.8 badge......?


/I retreat to my safe haven in preparation of the bombardment
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Not a bombardment, just an example. Again I have to ask you where you get the impression that the nifty at 1.8 is soft? Certainly it has quite a narrow DoF at 1.8, which means that if you don't get your focussing spot on, your resulting image will be soft, basically because it is out of focus, not because of poor performance from the lens.

This image was taken on a nifty at 1.8 with the focus on the eye. The 'fur' around it is in focus, but the focus falls off quite rapidly due to the shallow DoF. You can actually see the plane of focus on the 'wing' on the left of the image.

nifty.jpg
 
alastairb said:
i have a feeling this might be because in the day when you do it your eye is adjusting so it doesn't get too bright, try it in a dimly lit area and the f/1.4 lens will be a lot brighter than the f/2.8 one
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I have heard about this - what you see through the viewfinder is limited to about f/2.5 even with an f/1.4 lens, in both brightness and depth of field effects. Chuck Westfall of Canon said so, and he knows.

I don't have a lens faster than f/2.8 so can't test anything, but I'd really like to know what's actually happening, and why.
 
If you want to see what aperture your viewfinder is like can't you just set an aperture and then hit the dof button? If the view gets dimmer set a wider aperture and try again until it doesn't. Trial and error should give you some idea in not much time at all.
 
It's all down to ease of use. I prefer a better photographic experience rather than pinsharp pictures. That said i feel I think about my photography a little more when using a prime.
 
HoppyUK said:
I have heard about this - what you see through the viewfinder is limited to about f/2.5 even with an f/1.4 lens, in both brightness and depth of field effects. Chuck Westfall of Canon said so, and he knows.

I don't have a lens faster than f/2.8 so can't test anything, but I'd really like to know what's actually happening, and why.
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Tracked down our best buddie Chuck W :) The false depth of field effect is down to the focusing screen surface (microlenses) and it varies. Brightness however is still transmitted accurately, according to relative f/number.

Here's the link http://digitaljournalist.org/issue0804/tech-tips.html
 
Crofts said:
I like deluded! :)
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It's not supposed to be a compliment! But it's nice to find a Leica lover with a sense of humour :D

Returning to my earlier question on that trip you referred to using just a 30mm lens, how many shots were taken with an f/number lower than f/2.8?
 
As far as what the OP says regarding not being able to use the 'complete lens' due to sharpness issues, I doubt most of us actually use out lenses to their maximum potential, especially where zooms are concerned.

I'm moving into primes for one reason and one reason only - shallower DoF. However, without my zooms I'd be lost, especially when shooting for mags, because they allow you to work in confined spaces and still get the shot.

As far as apparent sharpness goes there are a lot of pixel peepers here who'll be deeming an image zoomed in at 600% as not being sharp enough. Think about viewing distance when it comes to your shots - you don't need to have your nose to the screen/print to experience it fully!!
 
photon said:
http://uk.leica-camera.com/news/news/2/6121.html
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They gave Woody Allen a Leica M8.2! Did he thank them for it? It was a disgracefully bad camera (and hurredly discontinued). That's funny.

david1701 said:
I love lecias and I like to think I have a sense of humour :D:D:D:D:D:D:D:p
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Forty years ago maybe. You need a sense of humour to even contemplate owning one today. Ridiculous poncy things. Would that be in leopard skin and sapphires, or plain old alligator and gold?
 
Returning to my earlier question on that trip you referred to using just a 30mm lens, how many shots were taken with an f/number lower than f/2.8?
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100% were taken at f2.8 (the maximum aperture of that lens). That was partly because I would have taken nearly all of them at f2.8 anyway - and partly because the lens was broken and wouldn't stop down any further! :)
 
Crofts said:
100% were taken at f2.8 (the maximum aperture of that lens). That was partly because I would have taken nearly all of them at f2.8 anyway - and partly because the lens was broken and wouldn't stop down any further! :)
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:LOL:

I like this one - he can stay...
 
ooo a nice Balvenie for me please - just a small dash of water in that, cheers...
 
Crofts said:
100% were taken at f2.8 (the maximum aperture of that lens). That was partly because I would have taken nearly all of them at f2.8 anyway - and partly because the lens was broken and wouldn't stop down any further! :)
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Class answer :)

Arkady said:
:LOL:

I like this one - he can stay...
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:D
 
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