Canon 1DX Mark 2 / Canon 24mm underexposing at close focus distance

[ballyscanlon]

Hi.

i've used the canon 24mm 1.4 II extensively with my 5D mark 3 and often shoot very close with it so i am used to the vinetting etc.  But since getting my 1DX MARK 2 i have had this recurring problem.  when shooting close (really close 1.5ft and closer) with this lens and camera seriously under exposes the image (at least a stop or 2).  as ive used the lens for a few years now i can say its a new problem with this new body.  the lens was factory tuned up last year and again, no issues with the 5D so im focusing on the 1DX mark 2 for now.

no issues with exposure on any other lenses regarless of focus distance.

i am attaching some examples:  i shot an excel spreadsheet page so the subject was self illuminated (no backlight issues), each one is noted with the pertainent settings

24mm @ 2ft distance  (ISO 100, 1/400s, 1.4)

24mm @ <1ft distance (almost at its minimum)  (ISO 100, 1/1250s, 1.4)

50mm (1.2) @ 2ft distance  (ISO 100, 1/500s, 1.4)

50mm @ > 1.5 ft distance (almost at its minumum)  (ISO 100, 1/500s, 1.4)

camera was at aperture priority and iso was at AUTO.  asyou cans see from the settings the shutter speed for the close focus 24mm frame is 1.3 stops under from the other 3 frame (giive or take).

camera had been brought back to factory settings before testing, meter is at 'evaluative metering'.

ive included 2 pictures i have taken in the same scenario (screen grabs with the histogram included), as you can see they are well underexposed).

anyone with this camera lens combo able to replicate this issue?

thank you

john

[ScottyP]

Just curious but does it work better with spot metering?

I wonder if this is a software glitch in need of a fix. 

[ballyscanlon]

hi scott.

spot metering fixes it.  actually over-exposes it (to my eye).

i forgot to mention that i had tested that previously.  

unfortunately spot metering isnt my typical metering setup, otherwise id just get on with using it.

thanks

john

[kvbarkley]

You do know that with a full sheet of white paper in the field of view, it will set the exposure to make it 18% grey.

In the first case, the black background averages things so that when it sets things to 18%grey, the black is black and the white is white.

It is the same reason you need to over-expose snow. So your first examples don't tell us anything.

[ballyscanlon]

so you would consider the second image  (24mm <1ft distance) properly exposed?  or the 2 last images properly exposed.

do you have a suggestion to offer as to what might be going on?

[ebiggs1]

No I don't.   But as Mr Barkley suggests the camera is trying to adjust everything to 18% gray.

"All DSLRs have limits to what they are capable of."   This is confirmed by the difference you and I see in the different way we set exposure,  partial, spot or evaluative, etc.

You really can't compare the way your 24mm lens reacts to exposure the same way your 50mm does.  The Acceptance of Angle is different for both.  This is basically why you see vignetting more with the 24 than the 50. I think it is just one of the things a photographer needs to file in a brain cell to recall in the future when needed.

[ebiggs1]

One other thing that doesn't help is the DR in this instance is beyond what a DSLR can capture.  If you feel you should be seeing better, or at least different performance, by all means give Canon Support a call.

[ebiggs1]

I don't have the ef 24mm f1.4L but I do have a lens with a 24mm focal length.  I don't have a 1Dx Mk II either but I do have a 1 series.  Just for curiosity here is how the Mk IV treats a similar situation.  I suppose the 5D Mk III might be even different.

The difference in the two is shows the different exposure modes and how each will effect the shot.

I think your camera and lens are working properly.  You just need to know how the camera interprets this situation or any situation for than matter and go with it. All DSLRs have limits to what they are capable of.  The rest is up to you.  When using this same combo for a more reasonable exposure, how does it do?  I'll venture it is fantastic!

Shoot RAW and post edit in PS and all is well.

[TTMartin]

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@ballyscanlon wrote:

Hi.

i've used the canon 24mm 1.4 II extensively with my 5D mark 3 and often shoot very close with it so i am used to the vinetting etc.  But since getting my 1DX MARK 2 i have had this recurring problem.  when shooting close (really close 1.5ft and closer) with this lens and camera seriously under exposes the image (at least a stop or 2).  as ive used the lens for a few years now i can say its a new problem with this new body.  the lens was factory tuned up last year and again, no issues with the 5D so im focusing on the 1DX mark 2 for now.

no issues with exposure on any other lenses regarless of focus distance.

i am attaching some examples:  i shot an excel spreadsheet page so the subject was self illuminated (no backlight issues), each one is noted with the pertainent settings

@24mm @ 2ft distance  (ISO 100, 1/400s, 1.4)

@24mm @ <1ft distance (almost at its minimum)  (ISO 100, 1/1250s, 1.4)

@50mm (1.2) @ 2ft distance  (ISO 100, 1/500s, 1.4)

@50mm @ > 1.5 ft distance (almost at its minumum)  (ISO 100, 1/500s, 1.4)

camera was at aperture priority and iso was at AUTO.  asyou cans see from the settings the shutter speed for the close focus 24mm frame is 1.3 stops under from the other 3 frame (giive or take).

camera had been brought back to factory settings before testing, meter is at 'evaluative metering'.

ive included 2 pictures i have taken in the same scenario (screen grabs with the histogram included), as you can see they are well underexposed).

anyone with this camera lens combo able to replicate this issue?

thank you

john

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Use the EOS utility to make sure that the camera has data for that lens installed in the camera.