7D underexposing

[Giulio Zanni]

My 7D underexposes about 2/3 compared to my MkIV. Both cameras are set with same preferences. Is that normal or should I get it adjusted?

Giulio

[Charles Glatzer]

Are we talking difference in in-camera metered exposure? You have different mag factors in the cameras and much depends on the meter pattern in use, and the size of the elements therein.

If you manually set the aperture, shutter speed and ISO similarly in both cameras and shoot an image do they look the same?

FYI- you can set a -/+ overall exposure bias adjustment via CF in the camera if necessary.

Best,

Chas

[Axel Hildebrandt]

I agree with Charles, sounds like a metering issue. Do you use evaluative metering on both cameras?

[Robert Amoruso]

Giulio,

Try this simple test. Aim Mark IV at blue sky and using no exposure compensation, make image. Do same for 7D. Compare histograms. If 7D luminance histogram is lower (towards left) then Mark IV, that will tell you it is exposing differently.

Use Chas' suggestion to correct it.

[Jeff Cashdollar]

I have both cameras and will try this too - more later.

[Giulio Zanni]

With both cameras set exactly the same I need +2/3 in AV on the 7D to get the same result I get on the MkIV at 0. It is quite disturbing as I mostly shoot from hides with both cameras at the same time...I'll try to adjust the 7D via custom function as suggested. Thanks, Giulio

[Axel Hildebrandt]

With both cameras set exactly the same I need +2/3 in AV on the 7D to get the same result I get on the MkIV at 0. It is quite disturbing as I mostly shoot from hides with both cameras at the same time...I'll try to adjust the 7D via custom function as suggested. Thanks, Giulio

Have you tried if different metering settings on the 7D make it more like evaluative metering on the Mark IV?

[Giulio Zanni]

Have you tried if different metering settings on the 7D make it more like evaluative metering on the Mark IV?

I'll try that but usually in evaluative you should get the brighter results. With average you usually get more underexposure and spot is a different ball park, it much differ from where you point the camera...

[Charles Glatzer]

Sounds like a metering problem, rather than camera problem. Try our suggestions above...and get back to us. Both cameras see the scene differently with the same lens, as the crop factor is different.

If you set the same exposure into both cameras is there a difference in the end result?

Chas

[Flavio Rose]

In this review

http://www.the-digital-picture.com/R...ra-Review.aspx

for a comparable final image to those obtained with other Canon cameras, the reviewer added +1/3 EV to the 7D.

[Charles Glatzer]

In this review

http://www.the-digital-picture.com/R...ra-Review.aspx

for a comparable final image to those obtained with other Canon cameras, the reviewer added +1/3 EV to the 7D.

And, the relevant statement is " my 7D delivered exposures that are 1/3 stop darker than my compared-to bodies at the identical exposure settings"

Quite a number of Nikon bodies exhibit 2/3 EV under-exposure from Canon and an incident meter. Best to test your cameras against each other with manually set identical exposure settings.

Chas

[Jeff Cashdollar]

Flavio,

The article you reference is a great read as well. Interesting notes on the 7D's noise and sharpness functionality.

I shoot both bodies and will test it myself later today.

[WILLIAM PERRELLI]

I thought it was an exposure issue{vs. my 50d}, and so did Canon's techs.

Is there any adjustments that can be made via the menu??

Thanks

[Flavio Rose]

I'm embarrassed to say it didn't occur to me until now to try to answer this question with dxomark.com. According to this website, at ISO 400 the true ISO of the 1D4 is 336 and the true ISO of the 7D is 325. The 5D2 curiously is 285. Now, I unfortunately have no clue how much variation there is from copy to copy in this characteristic of a sensor.

Rereading the original question it's not clear if it is referring to (a) "true ISO" (how bright the same image turns out when photographed with the two cameras with the same lens at the same settings of ISO, aperture and shutter speed) or (b) the behavior of the "Evaluative Metering" automated exposure setting determination function when you use P, Av, Tv. Having gotten a 7D recently, I am still learning about the latter function (which I understand has changed since my previous camera, an XTi), but the behavior is unfortunately inclining me towards greater use of manual exposure.