Why ISN'T my photo overexposed ?

Hi Guys,

I've long suspected that there's either something wrong with my cameras exposure system or I've really got no idea what is going on, a possibility I freely admit !

I "generally" have to set my Ev to around +1 to get what I consider to be "properly" exposed images.

Anyhow, this morning I needed to do some height tests so I grabbed the ironing stand, jury-rugged it upright, applied some masking tape to head-height and then grabbed the camera.

The setup is in the lounge room, pretty dark with all the curtains closed, the only illumination being the overhead pendant light that has three 60 watt globes.

The photos posted are .jpg from the camera, imported to PSP, rotated, resized and saved.

Exhibit 1 (1860) is somewhat reasonably correctly exposed, HOWEVER as shown by the camera-back is in Av mode, f/2.8 with one-and-two-thirds stop of +Ev dialled in.

WHY doesn't it look (nearly) two stops overexposed ?

Exhibit 2 IN POST BELOW (1861) is the same shot, again in Av mode, but this time with 0 Ev compensation.

Why does it look underexposed ?

Many thanks,

Austen.

Continued from above......

Image 1861

Thanks guys,

Austen.

Your metering mode, what you pointed your metering area onto, your picture style, and the type of lighting will all play a part on how good the exposure ends up being with your JPG result, even with EC raised up. Also, many of the times you will find that all Canon cameras will underexpose a bit at EC 0 in Av or Tv modes. This is why many of us pretty much leave EC on +1/3 to +2/3 all the time.

Try a different metering mode with the same EC and see how the results turn out. Make sure you use the neutral picture style as well.

Your first posted shot definitely shows nearly a 1 2/3 better exposure than the EC0 shot, so your EC is working just fine.

TeamSpeed wrote in post #16433159
Your metering mode, what you pointed your metering area onto, your picture style, and the type of lighting will all play a part on how good the exposure ends up......

As I said, I've noticed that "generally" they are underexposed unless I give it a boot-full of +Ev regardless of the scenario

TeamSpeed wrote in post #16433159
.....many of the times you will find that all Canon cameras will underexpose a bit at EC 0 in Av or Tv modes. This is why many of us pretty much leave EC on +1/3 to +2/3 all the time.
...

Seriously.......

NOW I find this out ??

Had the camera for umm five years now and this is the first I'm hearing of this !!!

There's me been thinking that I've got no idea what's "wrong" with the camera, what could I be doing wrong, what is happening to give me consistently underexposed images ?

TeamSpeed wrote in post #16433159
.....Try a different metering mode with the same EC and see how the results turn out......

Changed metering modes (just shot the one at 0Ev) and same (underexposed) result

So really, there's probably nothing "wrong" as such, I just need to be mindful that I DO need to dial in some +Ev and that's just a quirk of (some / many) Canon bodies ?

Really glad I learnt this before I spent $$ on a FF (Happy Christmas to me ) and got all bitter and twisted because my photos were STILL underexposed !!!

Attached same as above my Metering Mode changed and 0Ev dialled in.

Thanks,

Austen.
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What picture style are you using?

TeamSpeed wrote in post #16433420
What picture style are you using?

Ahh....

Portrait.

Does / should that matter ?

Thanks heaps,

Austen.

The picture style will impact your histogram and your final JPG. If it is the stock portrait and not an altered one, it should not make that big a difference.

Have you tried this experiment with lighting other than artificial lighting? What kind of lighting are you using? Also, I wouldn't put the center of the frame on a target that is 1/2 black and 1/2 white. What if you shoot something else in the same room, like put the chair in the center of the frame?

TeamSpeed wrote in post #16433465
.....Have you tried this experiment with lighting other than artificial lighting? What kind of lighting are you using ?

Yes, it's a consistent effect shooting indoors or outside........

The setup is in the lounge room, pretty dark with all the curtains closed, the only illumination being the overhead pendant light that has three 60 watt globes.

TeamSpeed wrote in post #16433465
.....What if you shoot something else in the same room, like put the chair in the center of the frame?

Is this what you meant ?

The result seems to be about the same ...............

Thanks,

Austen.

Charlie,
A meter assumes that a scene's various areas all average to mid-tone level of tonality. A spotmeter assumes that it is pointed at an 18% tonality mid-tone. If the scene does not AVERAGE to mid-tone, or the spotmeter is not pointed to an 18% tonality target, the meter will suggest the wrong exposure and not 'proper exposure'. The classic example is trying to shoot one of these:

• Scandanavian bride in white gown in a snow scene...you end up with grey gown in front of grey snow
  
• Black cat in a coal mine...you end up with gray cat in gray background
  

Wilt wrote in post #16433572
......Your scene is NOT 'average'...it is brighter than average. That is why, shooting that scene, one needs to dial in EC

Thanks for the reply, but I'm not sure that my lounge room, illuminated only by three small 60 Watt globes in a ceiling pendant would be brighter than average ?

The settings are as follows ............

Av
Exposure = 1/100 Somewhere "average", if there's such a thing ?
Aperture = f/2.8 Wide open on my 24mm-70mm Lens
ISO = 1,600 Quite a high ISO ?

I would have thought that with these settings, even in an "average" lit room you would get overexposure ??

As my photographs are underexposed at these settings, wouldn't that indicate a "dark" room ?

Or have I totally missed the plot yet again

Thanks,

Austen.

EDIT: BTW, Nice avatar

I just went into the loft area which has a large (east facing) window that doesn't currently have direct sunlight on it.

If asked I would have said that the area was "nicely" lit.

I set my camera to manual and using the same setting as above (1/100 / f/2.8 / ISO 1600) and took another photograph.

I think it was significantly over-exposed, the black on the histogram image is the "Clipping Blinky".

Cheers,

Austen.

charlieharper wrote in post #16433611
Thanks for the reply, but I'm not sure that my lounge room, illuminated only by three small 60 Watt globes in a ceiling pendant would be brighter than average ?

The settings are as follows ............

Av
Exposure = 1/100 Somewhere "average", if there's such a thing ?
Aperture = f/2.8 Wide open on my 24mm-70mm Lens
ISO = 1,600 Quite a high ISO ?

I would have thought that with these settings, even in an "average" lit room you would get overexposure ??

As my photographs are underexposed at these settings, wouldn't that indicate a "dark" room ?

Or have I totally missed the plot yet again

Thanks,

Austen.

The level of illumination in a scene should ALWAY results in shots with black items black, 18% items as 18% mid tone, and white items as white, with a 'proper exposure'...in a 'proper exposure' the three tonalities are portrayed AT THEIR INHERENT BRIGHTNESS, resulting in peaks in the histogram similar to that last illustration -- whether I am shooting in bright sun, or I am shooting in dim indoor lighting at night.

You wall is significantly brighter than middle grey density. You curtains are somewhat brighter than middle grey density. In reality.
In your photos they both are darker than their inherent brightness simply because you meter was fooled by a brighter-than-average scene...there is not much black in the scene, is there?!

Thanks for all the help guys, this is great !

Wilt wrote in post #16433643
......You wall is significantly brighter than middle grey density. You curtains are somewhat brighter than middle grey density. In reality......

I stuck the dog in front of them, he's a Golden Labrador and snapped a "Phone-photo"

Curtains are a bit brighter than middle grey, but there's not a lot in it ?

It seems the 'phone (LED flash OFF) has got the exposure closer than the Canon ?

Thanks,

Austen.

You are wasting your time doing tests without a standard target. Copy this image to your PC (if Windows, right-click, then Save As...)

Now frame the same area with your camera, as you did with your phone. Results should be similar.