Why are my pictures overexposed?
Why are my pictures overexposed?
I've been taking pictures with my Nikon D3100 using my new prime lens (35mm F1.8). When I took pics today I noticed many of the pics were overexposed. All pics were taken using aperture priority mode, mostly portraits shots of my daughter and her friends at the local outdoor mall. The pics were taken around 7-8pm so the light wasn't harsh. Also many of the pics were shot at the smallest aperture setting, either F1.8 to F2.2.
What am I doing wrong?
Low f numbers like 1.8 and 2.2 are actually wider apertures, and they allow much more light in through the lens.
Although that really shouldn't have been a problem at night.
Make sure your ISO isn't up too high or your exposure compensation set to +1EV or something.
Make sure its at 0EV
You are NOT using the light meter to set the correct exposure. Look through the viewfinder and make sure that the light meter shows you are exposing the image properly. Look on page 6 of your user manual for more detail. The exposure indicator is number 17 and pages 79 and 80 provide more detail. Page 25 shows you how to hold the camera while using the viewfinder
Why you are using a 35 mm lens for portraits is a puzzle. Portrait lenses are medium telephoto lenses like the 50 mm in the case a lens for use with your camera. The longer the lens, the more out of focus the background is when shot wide open
Just so you know, the "smallest" aperture would be f/22. At f/1.8 or f/2.2 you are using the lens with the aperture wide open or at its largest aperture.
F1.8 to f2.2 is actually the largest aperture. What was probably happening was the shutter speed was unable to go any faster and the ISO was either unable to compensate or was fixed at a constant value. F1.8 lets in a ton of light… Pretty much anything that is struck by direct sunlight is too bright.
You need to use a smaller aperture or select the program mode or an automatic mode. I find F1.8 give way too shallow a depth of field to do candid snapshots on the 35mm. 2.8 is about the best for bokeh with a sharp subject.
Don't listen to the naysayers who say you can't shoot portraits with this lens; not everybody wants to haul around a 50mm or 70mm lens that is good for almost nothing else just for the chance to take some candid portraits of children.
If you're using aperture priority, you shutter will adjust as necessary. Unless you were shooting at ISO 25, 000 or something ridiculously high like that, the possibility of your shutter not being able to shoot fast enough is not even a remote possibility.
1. Make sure you're not using a super high ISO
2. Check the metering MODE. If you were using the spotmeter mode and the spot was on a very dark area, then the image will be (correctly) overexposed. If you're using spotmeter, you have to know exactly where the meter is reading. Otherwise, use matrix metering. Sometimes you can use matrix metering, and then change to manual (starting with the settings you used in matrix) and adjust accordingly.
F1.8 & f2.2 are the widest aperture setting (most light). When you are in aperture priority mode, there's no light meter visible (only when in manual), as the shutter speed should adjust automatically.
Check metering mode (spot, CW or evaluative) as large areas of light/dark can affect the image depending on mode.
Posting some examples (eg on Flickr) with EXIF data might help.
I would've switched to manual mode & seen what the meter was giving me. Don't forget A mode is an AUto mode, and Auto modes sometimes get it wrong. Having the camera on Auto ISO can sometimes screw things up - I have this function off permanently.
Is the lens new? If not, it's possible you had sticking aperture blades.
NB - whilst you can shoot portraits with ANY lens (& I've used wide angles before now), do be aware that anything below 50mm is going to give you some distortion, if used close to the subject.
F/1.8 is the largest aperture setting of the lens. The smallest should be f/22 or f/32.
Check that EV is at zero. That's the number line you have at the status screen when you press the button half-way. Read the manual about EV or Exposure Value.
Actually at the maximum aperture or close to it, the smallest aperture is at f16 or thereabouts. But indeed it's good to work close to max aperture if the light is fading and/or you want the background to be blurred. Maybe you had the exposure compensation set off centre, towards 'plus'. Maybe you had too high ISO, but unlikely, even at 800 or 1600 the shutter speed should have automatically gone higher.