How will new ultra high ISO bodies impact f/2.8 telephoto zoom lenses?

[neuroanatomist]

@Brian - I believe Edwin is referring to my comment early in the thread, about how ultrafast lenses (f/1.4, f/1.2) don't provide the light-gathering advantage on a dSLR that most people think. Film was a different story, but digital sensors aren't able to efficiently capture photons at high angles of incidence. So, with an f/1.2 or f/1.4 lens on a dSLR, the camera acutually clandestinely increases the ISO by up to half a stop or more (greater effect with wider apertures and smaller pixels). For example, say you're shooting in Av mode with a 50/1.4 at 1/100 s, f/2, ISO 1600. You change the aperture to f/1.4 without changing the ISO, and you expect the shutter speed to go to 1/200 s - and it does. But, the sensor can't actually capture the full additional stop of light at f/1.4, so instead it adjusts the ISO to 2000. You don't know that from the settings - the EXIF shows the ISO 1600 you set. However, you have an extra 1/3 stop of noise in your shot.

 

[Hillsilly]

Is this what they call "automatic vignetting correction"?

 

[briansquibb]

@Brian - I believe Edwin is referring to my comment early in the thread, about how ultrafast lenses (f/1.4, f/1.2) don't provide the light-gathering advantage on a dSLR that most people think. Film was a different story, but digital sensors aren't able to efficiently capture photons at high angles of incidence. So, with an f/1.2 or f/1.4 lens on a dSLR, the camera acutually clandestinely increases the ISO by up to half a stop or more (greater effect with wider apertures and smaller pixels). For example, say you're shooting in Av mode with a 50/1.4 at 1/100 s, f/2, ISO 1600. You change the aperture to f/1.4 without changing the ISO, and you expect the shutter speed to go to 1/200 s - and it does. But, the sensor can't actually capture the full additional stop of light at f/1.4, so instead it adjusts the ISO to 2000. You don't know that from the settings - the EXIF shows the ISO 1600 you set. However, you have an extra 1/3 stop of noise in your shot.

8) 8) 8)

 

[Viggo]

Should think It would have more affect on the need for fast wide angle primes! Really any need for a 24mm 1.4 anymore?

Have you ever used a 24 f1,4 L II on a fullframe body?? The look of the picture you get at that wide angle and that shallow depth can't be done by anything else.

Nope, never have, but I would certainly love to see an example of a real world shot using the 24 1.4 wide open [out of 100 shots - how many @ 1.4?] compared to ones shot at f2 or even 2.8 - real difference? care to share? Anyway, I didn't really mean to suggest that nobody would want the faster wide angle lens, but they are pricey, big and the DOF advantages aren't as obvious [compared to telephotos]. I'm simply surmising that many [most?] folks will find less need for them as high ISO performance improves. If Canon made a nice 24mm f2 L - I'd be all over it!

I'll go out on a limb and predict that across the board - high ISO cameras will increasingly cannabalize [not eliminate] the sales of fast [zoom and prime] lenses for ALOT of shooters - how could it not? Size and price really do matter!

Here's how my son looks when I tell him something he doesn't think is true, the skeptic look

http://photobyviggo.com/random/mail31.jpg

Shot with the 50L on a 5d @1,2

 

[neuroanatomist]

Is this what they call "automatic vignetting correction"?

Nope.

 

[pharp]

Should think It would have more affect on the need for fast wide angle primes! Really any need for a 24mm 1.4 anymore?

Have you ever used a 24 f1,4 L II on a fullframe body?? The look of the picture you get at that wide angle and that shallow depth can't be done by anything else.

Nope, never have, but I would certainly love to see an example of a real world shot using the 24 1.4 wide open [out of 100 shots - how many @ 1.4?] compared to ones shot at f2 or even 2.8 - real difference? care to share? Anyway, I didn't really mean to suggest that nobody would want the faster wide angle lens, but they are pricey, big and the DOF advantages aren't as obvious [compared to telephotos]. I'm simply surmising that many [most?] folks will find less need for them as high ISO performance improves. If Canon made a nice 24mm f2 L - I'd be all over it!

I'll go out on a limb and predict that across the board - high ISO cameras will increasingly cannabalize [not eliminate] the sales of fast [zoom and prime] lenses for ALOT of shooters - how could it not? Size and price really do matter!

Here's how my son looks when I tell him something he doesn't think is true, the skeptic look

http://photobyviggo.com/random/mail31.jpg

Shot with the 50L on a 5d @1,2

Like it, nice shallow DOF, but with a 50, not the 24mm. I currently use the Zeiss 35mm f/2 the most and have personally never felt the need for anything faster, but it appears a good case can be made for the 1.4 wide angles even with the high ISO bodies. I've been looking at something in the mid 20s range and will probably get the new Zeiss 25mm f/2. I'd consider a Canon, but I don't they don't make a 24 f/2L.

 

[neuroanatomist]

I've been looking at something in the mid 20s range and will probably get the new Zeiss 25mm f/2. I'd consider a Canon, but I don't they don't make a 24 f/2L.

I don't understand this...Canon makes a 24mm f/1.4L II, and it can be used at f/2, of course. Since that's a stop narrower than wide open, at f/2 you'd get the optical benefit of not using a lens at it's widest aperture. The Zeiss lens is not much larger or heavier than the Canon, and the Canon lens is weather-sealed and has autofocus.

 

[pharp]

I've been looking at something in the mid 20s range and will probably get the new Zeiss 25mm f/2. I'd consider a Canon, but I don't they don't make a 24 f/2L.

I don't understand this...Canon makes a 24mm f/1.4L II, and it can be used at f/2, of course. Since that's a stop narrower than wide open, at f/2 you'd get the optical benefit of not using a lens at it's widest aperture. The Zeiss lens is not much larger or heavier than the Canon, and the Canon lens is weather-sealed and has autofocus.

I was joking - sort of, but I really do like the look of the pictures from my Zeiss 35mm - can't put my finger on it. I personally don't care that much about autofocus or weathersealing. You're right though - the new Zeiss is a beast and pricier than the Canon. I'm actually still weighing my options.