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cogitech
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p.2 #1 · Stop down metering - how?

ghozer wrote:
Holy cow the contrast and detail in that image is marvelous. Of course that's EXACTLY why I bought this lens!

Thanks for the info. I didn't think the Cameraquest adapter was an AF confirm chip though. ??

When I use non-AF-confirm, my camera does not report any aperture (00) so I assumed you are using one if your camera reports f2.8.

Mar 29, 2008 at 12:48 PM

ghozer
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p.2 #2 · Stop down metering - how?

mh2000 wrote:
Isn't that easier than all the variable EV correction?

>>So, I went out side and just based the exposure on the sunny 16 rule and I got perfect exposures.

You can say that again. As a backup to my idiocy with math I ordered an analog sekonic light meter online last night.

Mar 29, 2008 at 02:20 PM

jonboring
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p.2 #3 · Stop down metering - how?

>> If the camera "knows" the lens it can compensate and calculate the right exposure. Quite understandably, the camera doesn't know alternative lenses and has no clue about the aperture, and this usually results in overexposure. <<

Huh? With manual lenses, you compose wide open and then stop down the lens with your fingers. With auto lenses, the electronics do it for you. Either way, the aperture blades move and the amount of light that gets metered is effected.

Mar 29, 2008 at 02:45 PM

Alex
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p.2 #4 · Stop down metering - how?

jonboring wrote:
>> If the camera "knows" the lens it can compensate and calculate the right exposure. Quite understandably, the camera doesn't know alternative lenses and has no clue about the aperture, and this usually results in overexposure. <<

Huh? With manual lenses, you compose wide open and then stop down the lens with your fingers. With auto lenses, the electronics do it for you. Either way, the aperture blades move and the amount of light that gets metered is effected.

Well it is a bit more complicated than that

. We all know that when we close down 1 stop the sensor gets 50% of the light. When we close down 2 stops it is 25% and so forth. With the metering sensor located behind the focusing screen it is not as straightforward. Because of how the screen is made when you close down 1 stop the sensor usually gets less than 50% of the light. This gets much worse when you close down further. The modern cameras know the screen and native lens parameters and are able to compensate for this mess. Unfortunately it doesn't work with alternative lenses. Again, my very limited experience with 5D and Mamiya M645 lenses on a Mirex adapter with focus confirmation indicates that an EES screen is much more consistent.

Alex

Mar 29, 2008 at 03:11 PM

ovredal73
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p.2 #5 · Stop down metering - how?

Most of my wide aperture alt. lenses overexpose by about a stop on my 5D when shot wide open. When stopping down a stop or two, they expose correctly.

Mar 29, 2008 at 11:32 PM

asoames
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p.2 #6 · Stop down metering - how?

ghozer wrote:
Update: Not sure what happened but after making my previous post I picked up the camera and flipped the top dial around and voila! The shutterspeed starting moving in M mode.

Ghozer

The camera's main power switch has two positions. If you want to adjust shutter speed and aperture in M mode, you need to have the power switch in the second (most anticlockwise) position. Not exactly intuitive!

Hope this makes sense!

Jun 03, 2008 at 03:34 PM

Valorin
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p.2 #7 · Stop down metering - how?

This is interesting. My 5D seems to overexpose at large apertures, exposes more or less correctly at medium apertures and underexposes heavily at small apertures. I see no reason why it would be lens dependent, but I'm using Nikon AIS lenses with an AF confirm adapter.

As an aside, does anyone else find it quite difficult to remove their F mount adapter from the lens?

Jun 03, 2008 at 05:41 PM

Mike Tuomey
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p.2 #8 · Stop down metering - how?

ghozer wrote:
Update: Not sure what happened but after making my previous post I picked up the camera and flipped the top dial around and voila! The shutterspeed starting moving in M mode. So, I went out side and just based the exposure on the sunny 16 rule and I got perfect exposures. But, the cameras meter is worthless on my 1Ds III. I'm going to need to figure this all out manually or get a light meter.

Try setting the camera's aperture read-out to f1.0 and see what happens. I believe this is necessary for some dSLRs, not all. All my 1-series require it, fwiw. If you check the camera's aperture read-out with the lens mount empty and the shutter button pressed down halfway, and it reads anything other than "00" you have to set the aperture to the body's lowest f-stop reading, which is usually f1.0.

Here's the best link I have to stop-down metering. You need to scroll down a bit to find the section on it:

http://photonotes.org/articles/eos-manual-lenses/

Hope this helps.

Mike

Edited on Jun 19, 2008 at 10:57 AM

Jun 19, 2008 at 10:48 AM

StevenPA
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p.2 #9 · Stop down metering - how?

Mike Tuomey wrote:
Try setting the camera's aperture read-out to f1.0 and see what happens. I believe this is necessary for some dSLRs, not all. All my 1-series require it, fwiw. If you check the camera's aperture read-out with the lens mount empty and the shutter button pressed down halfway, and it reads anything other than "00" you have to set the aperture to the body's lowest f-stop reading, which is usually f1.0.

This was exactly my experience with the original 1Ds before I sold it.

Jun 19, 2008 at 02:40 PM

pascal03
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p.2 #10 · Stop down metering - how?

Tag ... for some good info.

Jun 19, 2008 at 03:22 PM

Cableaddict
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p.2 #11 · Stop down metering - how?

cogitech wrote:

For landscape work, I would just set it to infinity at f5.6 and push the bloody shutter release for a guaranteed perfectly (frighteningly) sharp photo.

P&S with stunning results!

Sorry for the size, but I think it is necessary in order for you to really understand what it is capable of. This is from a 350D, f5.6.

Cogitech, OMG!

Is that the Distagon 21mm? If not, then what the heck IS it?

I have been considering getting the amazing Nikon 14-24G for my 5D, but hate that it doesn't take filters. I think I may have found my new Holy Grail.

Edited by Cableaddict on Jun 20, 2008 at 03:37 AM GMT

Edited on Jun 20, 2008 at 08:37 AM

Jun 20, 2008 at 05:04 AM

melcat
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p.2 #12 · Stop down metering - how?

As Alex says, you need not to use the "bright" screen that comes with the camera. I am getting correct exposure on a 5D with Ee-s screen and a number of Zuikos at all stops. By "correct", I mean within 1/3 stop.

This is in spot and centre-weighted modes only - I have never used the evaluate or partial metering modes on this camera, even with the Canon lenses. I think it's quite likely evaluative metering uses the focal length as a parameter, and, not having that, the results are not as expected.

Jun 20, 2008 at 08:01 AM

Cableaddict
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p.2 #13 · Stop down metering - how?

Has anyone used this lens, on a 5D, with Brightscreen's #5 "Proscreen' ?

How does the metering respond?

Edited on Jun 20, 2008 at 08:40 AM

Jun 20, 2008 at 08:39 AM

RandomLetterz
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p.2 #14 · Stop down metering - how?

cogitech wrote:
You are using an AF-confirm chip adapter (which is why the camera thinks there's an f2.8 lens on it).

I'd try a non-AF-confirm adapter and see what happens.

You don't need to "focus" a CZ21. Just set the aperture to f11, then turn the focus ring so the infinity mark lines up with the right-side "f8" distance marker. You'll find that there is a combination that allows everything from 6ft to infinity to be in focus, which may vary slightly depending on adapter thickness, etc. Do some systematic tripod work for an afternoon and get to know her. For landscape work, I would just set it to infinity at f5.6 and push the bloody shutter release for a guaranteed perfectly (frighteningly) sharp photo.

P&S with stunning results!

Sorry for the size, but I think it is necessary in order for you to really understand what it is capable of. This is from a 350D, f5.6.

This image is copyrighted by the owner

This image is copyrighted by the owner

Is this castle(?) in one of the later (Pierce Brosnan) James Bond movies? Am I going crazy?

Edited on Jun 20, 2008 at 10:46 AM

Jun 20, 2008 at 10:42 AM

wkhc168
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p.2 #15 · Stop down metering - how?

Would it be easier if I use a light meter to determine exposure when I am using a MF lens?

Nov 11, 2008 at 09:58 PM


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