Underexposure with kit lens when shot through viewfinder

The_Traveler · Mar 19, 2013

Try testing on a tripod, shoot with viewfinder covered to see if light leaks from the viewfinder somehow are affecting exposure settings.

Kolia · Mar 19, 2013

The op knows that. That is the basis of his topic.

He asks WHY it being metered differently.

gsgary · Mar 19, 2013

Because he is moving and camera is metering on different areas as i said before its not rocket science

preahkumpii · Mar 19, 2013

@gsgary, I know that. The camera is setting the shutter speed. I want to why it is selecting two different speeds for the exact same shot.

@Kolia @cgibson1, thanks for the info. I tried the spot metering on a tripod and the shutter speeds are still different. I'm going to try to cover the eyepiece and see if that is affecting it. I think I have an understanding of what metering is, and how it is used, which is why is am stumped.

preahkumpii · Mar 19, 2013

Yes, I am testing on a tripod. I think some might have it backwards, as concerning extra light getting in through the viewfinder when in Live Mode. If that was the case, then the Live View mode shot would have a slower shutter speed. The reverse is actually true. The Live View shot is has a longer shutter speed, and thus a brighter pic.

gsgary · Mar 19, 2013

preahkumpii said:
Yes, I am testing on a tripod. I think some might have it backwards, as concerning extra light getting in through the viewfinder when in Live Mode. If that was the case, then the Live View mode shot would have a slower shutter speed. The reverse is actually true. The Live View shot is has a longer shutter speed, and thus a brighter pic.

Rubbish live veiw has shutter open longer

preahkumpii · Mar 19, 2013

gsgary said:
preahkumpii said:

Yes, I am testing on a tripod. I think some might have it backwards, as concerning extra light getting in through the viewfinder when in Live Mode. If that was the case, then the Live View mode shot would have a slower shutter speed. The reverse is actually true. The Live View shot is has a longer shutter speed, and thus a brighter pic.

Click to expand...

Rubbish live veiw has shutter open longer

Ok, sir. Look at the exif data I posted. 02.jpg is in Live View. Shutter speed is 1/4, which is slower than 1/6.

cgipson1 · Mar 19, 2013

you also have slightly different framing between the two shots... there is more junk in the frame on the second image... and with Pattern metering, that could be enough to cause the difference. The different framing tells me the camera was moved, and who know what else changed (if the camera was on a Tripod, WHY did the framing change?).

Was it outdoors? Did a cloud move slightly? Did the light change a tiny amount, that you didn't notice? Who knows, right? Too many variables! If you really want to test it, you need to cut out the variables... totally! If you even stood in different place, and cast a slight shadow... that could cause the difference!

The_Traveler · Mar 19, 2013

I suggested you test the light leak in conventional mode (not live view) to see if light is leaking in, fooling the camera as to the amount of light actually available, which then exposes for a shorter time when the mirror is up and out of the way.

preahkumpii · Mar 19, 2013

cgipson1 said:
you also have slightly different framing... there is more junk in the frame on the second image... and with Pattern metering, who knows what is causing the difference? The different framing tells me the camera was moved, and who know what else changed (if the camera was on a Tripod, WHY did the framing change?).

Was it outdoors? Did a cloud move slightly? Who knows, right? Too many variables! If you really want to test it, you need to cut out the variables... totally! If you even stood in different place, and cast a slight shadow... that could cause the difference!

Throughout these replies I have been testing it on a tripod without moving the camera at all. In the example I posted first I was holding the camera. However, in the 10 tests or so that I have done since, it has been on a tripod with the exact same frame. Testing has been indoors under artificial light. I also have been testing only with spot metering as well. This is starting to seem obvious that this is not common. I would be happy to post another test with camera on a tripod.

Thanks for the help!

gsgary · Mar 19, 2013

preahkumpii said:
Ok, sir. Look at the exif data I posted. 02.jpg is in Live View. Shutter speed is 1/4, which is slower than 1/6.

What is the difference between slower shutter speed and longer exposure as you wrote in your statement ? is it not the same

KmH · Mar 19, 2013

See page 104 -Exposure- of your D5100 user's manual.

Depending on the scene, exposure may differ from that which would be obtained when live view is not used.
Metering in live view mode is adjusted to suit the live view display, producing photographs with exposure close to what is seen in the monitor.

There is nothing wrong with your camera, nor the lens.

preahkumpii · Mar 19, 2013

KmH said:
See page 104 -Exposure- of your D5100 user's manual.

Depending on the scene, exposure may differ from that which would be obtained when live view is not used.
Metering in live view mode is adjusted to suit the live view display, producing photographs with exposure close to what is seen in the monitor.

Click to expand...

There is nothing wrong with your camera, nor the lens.

Odd, I have read over the manual. But, there is not a page 104 in mine. I do appreciate the info. I am curious though why using this lens with conventional mode it seems in general to be underexposed as compared to other lenses, yet it shows the exposure at 0 on the compensation scale. I realize I might not ever get an explanation to my curiosity. Thanks everyone for the help.

Adam

pgriz · Mar 19, 2013

The camera may be using different focusing points when in "normal" mode and in live-view. In many cameras, the metering is associated with the focusing points used. If your camera is set up this way, you will have differences in the two readings.

When trying to figure out why things are different, it helps to eliminate as many variables as possible. That usually means camera on a tripod (as gsgary mentioned), turning off all the auto functions, and varying ONLY the item you are investigating. So in this case, I'd put the camera on a tripod, select a specific AF point, and try to shoot the sequence: manual mode exposure (you set both the aperture and shutter speed, by zeroing the meter) through the viewfinder, Aperture-priority exposure (set the same aperture you used for the manual shot) using the viewfinder, then repeat the exact same sequence using live view. If this set gives you the exact same exposure each time, then you know that the camera does at least meter consistently. Once you have this baseline, you can change something (say, let the camera pick the AF point), and repeat the exercise. By doing this type of testing, you'll learn how the camera behaves (always a good thing), and you'll know what the different settings do.

preahkumpii · Mar 19, 2013

Ok, here is a test following pgriz suggestion. I took 4 photos, all of which were done on a tripod. I took two shots in the viewfinder (one manual with 0 on the meter, and one with aperture priority), and two in the live view (one manual with 0 on the meter, and one with aperture priority). As you can see the frame is the same in all. The metering method is the same in all.

Viewfinder | Manual | 10/16 | f6.3 | ISO100 | Note: I zeroed the meter manually.

Viewfinder | Aperture Priority | 10/16 | f6.3 | ISO100

Live View | Manual | 2" | f6.3 | ISO100 | Note: I zeroed the meter manually.

Live View | Aperture Priority | 2" | f6.3 | ISO100

So, as you can see, the Live View seems to just arbitrarily increase the exposure, unless there is some way to adjust this. I don't know. But, as pgriz said, it does seem to be metering correctly.