EOS M50 Mark II Art Photographs Underexposed

[DennisMerritt]

I'm photographing a friend's paintings and having a really hard time with exposure. I have an EOS M50 Mark II. I've tried all sorts of experiments, none have worked. For the purpose of this post I'll consider just one. I have a painting sitting in indirect sunlight near a window. I'm using P, evaluative metering, filters off, auto lighting off (disabled), picture style standard 4,2,4,0,0,0, white balance AWB-W 0,0. The shot was f/5.0, 1/60, iso 320. Brightness +/- 0. The picture comes out dark and I need photoshop to bring it to life. Here's the rub. I take a picture with my iPhone and it comes out perfect. Any help greatly appreciated. (I've had trouble with exposure in other contexts as well and wind up setting brightness high, but for this shot increasing brightness takes away the subtle colors of the rose) Here's the two shots: iPhone photoM50 (reduced size to upload)

[deebatman316]

What kind of lighting did you try using. What looks bright to us is dark to the camera.

[DennisMerritt]

What I don't understand is why the camera didn't adjust the shutter speed down to get the proper exposure. I've since been playing with M mode and f/3.5 (as you suggest) and slowing the speed, and I can get more light and again, get the details washed out of the picture. What's the difference between exposure compensation and pushing the shutter speed down? (I can use a tripod as the art isn't going anyway.)

[DennisMerritt]

I've got a couple of bright photography lights I used for the lighting experiments. No joy.

[DennisMerritt]

Right, it looks dark to the camera, but why did the iPhone see it like I do? It "knew" what exposure to use to take a perfect picture. (It's annoying how good the phone camera is. I don't want to shoot my friend's art with an iPhone when they came to me because I had a fancy camera.)

[deebatman316 · Accepted solution]

Your camera sees things in gray. So any very bright colors will fool the metering system. Then cause it to underexpose. Your phone works differently it meters with color. That’s Color Matrix metering. Canon doesn’t use this.

[kvbarkley]

Exposure compensation can adjust shutter speed, Aperture or ISO. If you have a particular reason to fix any of those, it is best to do it yourself.

[Waddizzle]

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@DennisMerritt wrote:

What I don't understand is why the camera didn't adjust the shutter speed down to get the proper exposure. I've since been playing with M mode and f/3.5 (as you suggest) and slowing the speed, and I can get more light and again, get the details washed out of the picture. What's the difference between exposure compensation and pushing the shutter speed down? (I can use a tripod as the art isn't going anyway.)

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I suspect the difference is in how the scene is metered and how that metering information is used.  The camera is using computational photography, its firmware.  The camera has it, too, the photographer.  

As I compare the two image, there is one thing that sticks out.  The metering.  If I assume that both images were metered at or near the bright, white area in the center of the flower, I see an obvious difference in the shade of the white.  The phone has rendered the area pretty much as white.  The camera has rendered the area more toward 18% Gray, which causes the entire scene to look darker.

The phone is able to calculate that exposure compensation is needed.  It is able to accurately estimate what the final captured image will look like with these settings.  If it thinks it is too dark, then the camera will add some exposure compensation to the settings before it captures the image.

The photographer is able to something similar by enabling a setting called ExpSIM.  This setting enables the camera to present an image to the photographer that simulates the exposure settings.  If you feel the image is too dark or to light, then you can tweak the final exposure using compensation.  

[DennisMerritt]

Thanks!

[Uneternal]

Take the picture in RAW mode and edit it afterwards. Slight underexposure is ideal for RAW.

If you want it to come out right out-of-camera, use exposure compensation. Or work in M mode entirely. Your camera should be on a tripod, your ISO should be 100, use a zoom of about 50mm, close the aperture to f/5.6 for better crispness and then adjust the exposure time accordingly, you'll probably need 1/15 or longer. Use a 3-second time delay to avoid camera shake. 

[Waddizzle]

I had a typo. The phone’s camera uses computational photography.   I left out the word phone.  

Computational Photography means that it uses AI to make your photos look better.  The end result is not an exact match to what was originally captured.