Overexposure problems – 5D and a new 24-105mm f/4.0L

RE: Overexposure problems – 5D and new 24-105mm f/4.0L

I was like a kid on Christmas day when UPS showed up with a new 24-105mm f/4.0L lens today. This lens was intended for my new-to-me 5D body.

Needless to say, I was immediately disappointed at the results. All of my exposures, no matter the ISO, shutter speed, or aperture setting seem to be overexposed by about 1+ stop; maybe even as much as 1 and 2/3rds.

At first, I couldn’t believe my eyes, so I tested it with the 16-35mm f2.8L at the same focal length. Then I went to a friend’s house and had him look at it too. We even tried his 17-40mm f/4.0L at the same focal length. Same results… the new 24-105mm is overexposing. I tried everything I could think of, including resetting all of the 5D’s settings back to factory default. But I'm still having the same issue. Your comments/suggestions would be greatly appreciated.

Below are results of a side-by-side comparison that represents tests with the other lenses we tried.

why are you using 2x the shutter speed on the 16-35?

is this on manual?

Those are not lined up right for comparison.

My fault. Let me start over. I don't think I explained this correctly. Rather, I should have said that my 5D is metering light differently between the 24-105mm and all of the other lenses I try. As a result, all of the exposures are overexposed by at least one stop.

I hope that explains my problems better. Sorry about the confusion.

What metering mode? What shooting mode?

And make sure you have custom function 00 set to the right focusing screen, if you've got it set to the wrong screen you can get discrepancies when moving from fast glass to glass slower than f/4.

That is pretty strange behavior. You can see that the exposures that are the same look the same, so it is kind of a mystery why the lens should meter differently.

Can you try shooting again a sequence but this time have some aperture selected so that both lenses are stopped down? Try f/8.

Also, try shooting a sequence in M mode to see if the aperture values are accurate.
Shoot:
f/4 - 1/250
f/5.6 - 1/500
f/8 - 1/1000

and see that all three have the same exposure.

perryge wrote in post #7241597
What metering mode? What shooting mode?

And make sure you have custom function 00 set to the right focusing screen, if you've got it set to the wrong screen you can get discrepancies when moving from fast glass to glass slower than f/4.

Ahhh... the focusing screen. Well, you might be on to something there. The new-to-me body came with a Brightscreen #4 & #5.

http://www.brightscree​n.com/styles.html

I have a feeling that is el problemo. I'll test the corresponding custom function first. But I wonder if I should try the "1:Ee-D" or "2:Ee-S" setting with the Brightscreen? Hmmm...

JeffreyG wrote in post #7241611
That is pretty strange behavior.

Can you try shooting again a sequence but this time have some aperture selected so that both lenses are stopped down? Try f/8.

Also, try shooting a sequence in M mode to see if the aperture values are accurate.
Shoot:
f/4 - 1/250
f/5.6 - 1/500
f/8 - 1/1000

and see that all three have the same exposure.

Good idea. I'll do that next and post in a bit if the above custom function setting doesn't fix things.

I also just noticed I wrote the aperture / shutters backwards for you there. Be sure to reverse them.

But before that I think Perry was on to the right answer. Check the focus screen. He would know as he bought the EE-S screen for his 5D only to find out that the EE-S screen was already in it.

phi376 wrote in post #7241693
Ahhh... the focusing screen. Well, you might be on to something there. The new-to-me body came with a Brightscreen #4 & #5.

http://www.brightscree​n.com/styles.html

I have a feeling that is el problemo. I'll test the corresponding custom function first. But I wonder if I should try the "1:Ee-D" or "2:Ee-S" setting with the Brightscreen? Hmmm...

That is DEFINITELY the issue. You need to find out which setting to use - probably best to contact the manufacturer, the brightscreen is known for having issues with the 5D: http://www.ascent-design.com/photo/Brigh​tscreen/index.html scroll to the tests at the bottom.

I was hoping the Focus Screen setting would have more effect, but it really didn’t make a huge impact. Albeit the “Ee-S” setting did seem to make a slight improvement.

Yes, that was my point - read the link I posted above. My point was that brightscreen + 5D = garbage.

Well, that settles it then. That gimicky piece of s**t is coming off tonight! Now, where did I put that crowbar??? Hahaha

I'll post the results after removal.

Do you have the original focusing screen?

Yes, it is suppose to be in the Brightscreen box that came with the camera. I am running out to my truck now to get it...

For sale: