Auto-Exposure with 24mm TS-E

[zafar1]

Hi

 

I am experimenting with a borrowed 24mm TS-E lens on my 5D. I have noticed that

the Auto-Exposure is off by more than two stops, when tilted or shifted.

 

Tilt-up: Under-expose

Tilt-down: Over-expose

 

Shift-Right/Shift-Left: Over-expose.

 

 

I have having to use AE lock at neutral position and then tilt/shift. Is this

normal or is there something wrong?

[akocurek]

I know Canon says to focus before using any movements. It might be the same with exposure. I too have to correct exposure after shifting.

[mark u]

You should meter before setting movements, and use M mode for preference. Failing that, you will have to work out an appropriate level of exposure compensation, e.g. by comparison with an external meter reading, or the pre-shift metered exposure provided the lighting is the same.

 

http://www.eosdoc.com/manuals/?q=TSE24L

[JDMvW]

I have a Nikkor 35mm PC and these problems are typical for any TTL metering, as well as for focus with a PC or TSE lens. Back in 1971 on my Nikon equipment, one had to watch carefully, especially when using the shift all the way out.

 

The good thing about digital, of course, is that you don't need to wait until the film comes back to find this out. ;)

[jeff_conrad]

This behavior is normal with any of the TS-E lenses; the amount of exposure

error varies with the lighting distribution, and isn't predictable. Manual

exposure is usually easier than using AE lock.

[obakesan]

Zafar

 

didn't get the manual with the lens?

 

also, this behavior will vary with film camera and D slr too, especially with flash. The flash metering (using canon flashes) with TTL on film cameras will not show such issues of altered exposure, while DSLR will.

 

This is because metering is from the focusing screen for exposure and off the film in TTL (when using film ;-)

 

Actually I was quite annoyed by this (among other 'features') when I bought my 10D to begin using digital to replace the film EOS. The systems are not as fully compatible as you'd think.

[ifeito]

Chris,

 

Your observed difference in behaviour comes from exposure sensor placement on crop sensor cameras in relation to "full frame" film cameras. For that matter you won't get the same exposure readings for the same scene with say a Rebel XT against a 1D MkIII.

 

Regarding the TS-E lenses, the behaviour described is absolutely normal. Instead of using the AE I would suggest that you use Manual mode, I've found I use it more and more and just watch the exposure meter before shooting with normal lenses. Of course with Tilt and Shift you determine exposure before adding any movements.

 

I don't understand how you're supposed to focus BEFORE tilting, since you need to take tilting into account before determining plane of focus (Google: Scheimpflug).

 

Hope this helps!

 

Ignacio

[alan_myers]

"Back in 1971 on my Nikon equipment, one had to watch carefully, especially when using the shift all the way out."

 

That's why a lot of Nikon PC lens users ended up with a Konica camera body in their bag, too, along with the Nikon-to-Konica lens mount adapter. The T, T2, T3 and T4 (and perhaps some other models, as well) will all TTL meter accurately with the PC Nikkor shifted.

 

Ignacio is correct with regard to the TS-E lenses... Meter before tilting and shifting, then set both parameters with the camera in M so the settings can't change. Alternatively, use a handheld meter to calculate your exposure settings, and leave the camera in M mode. The problem only crops up when using any of the auto exposure modes, or trying to use the camera's meter reading through and already shifted or tilted lens.