50mm or 85mm?

nancinator

I just discovered your site and forum. I am just learning what this camera can do. This is going to be so helpful and educational. Thank you for your simple, easy to understand teaching methods. ;) I currently have an 18-200mm zoom for my D5100 and would like to take portraits of our new grand baby as well as get professional looking group shots. I also love to take shots of my garden and the chickens. Can you advise me about the pros and cons of the 50mm vs 85mm? I realize the 85mm is quite a bit more expensive, but it's worth it to me if it will give me better shots with less distortion. Thanks so much.

ohyeahar

Since you have a superzoom lens, just try shooting with 50mm for a day versus 85mm for a day. See which focal length you prefer. On a crop sensor like the D5100, you’ll likely find that the 50mm is more useful.
Distortion isn’t an issue. There’s very little distortion on prime lenses compared to zooms lenses. Besides, any distortion can easily be corrected in post-processing.

bruto

I have both (not the ones here, but the same focal lengths). The 85mm gives a beautiful look when it's possible to use it at all, and on the DX format it's a medium short telephoto that works nicely for middle distances. The 50mm will be more useful more often, and is probably the best overall portrait lens for people. As Ohyeahar says, try the focal lengths using the lens you already have, which covers both, and decide which you find most convenient. At longer focal lengths, even the relatively slow zooms can provide very nice out of focus backgrounds, too.

Galan

You're lens that came with your camera is suitable for doing portrait photography.
I have done portrait photography, weddings (I hate them but they pay well), nature and freelance photojournalism.
I have a pretty advanced set of lenses from macro to Super (600mm f/4) as well as your coveted 85mm in f/1.8. Although it does have a great place in portraits, it is also quite intrusive to individual space, meaning you do have to effectively get in their face to compose. This is why I prefer the 105mm and your zoom lens will allow for captures that can awe your audience if you just learn how to use it effectively. Learn more about depth of field, and how long lenses 'compress' an image.
I know the fixed (lenses that do not have focal range) are better choices for portraiture because they have fewer moving parts (internal lenses) but we aren't doing magazine spreads, right?
Just remember that hand-holding a zoom lens follows a simple rule: 1/the focal length of the lens.
That means, if you are shooting a subject that is zoomed to 140mm, you need at least a shutter speed that matches (or exceeds) that number. 1/500th would be fine for hand-held at 140mm.
Enjoy your camera.

bruto

I would just add that that old "reciprocal rule" for hand holding, while it's fine for FX or full format, and a good general rule of thumb, is less useful for modern digital shooting, especially in DX. To begin with, you really ought to use the crop factor, so if you could hand hold a 50mm lens at 1/50 second in FX, it would call for 1/75 in DX.

On the other side, though, VR lenses allow much slower shutter speeds, and the rule of thumb is based on the likelihood of getting a good percentage of sharp shots. If you're shooting digital, you can shoot continuously, or make many shots, and even if you get only a small percentage sharp, you'll get some and can erase the rest. Always use the fastest shutter speed you can, but don't give up if you can't. Just take more shots.

Practice. You can get better if you work on it. If you're not sure what works and does not, you can test. Find a fairly dark indoor space in which you can focus on small circular lights, such as the pilot lights on electronic equipment. Try at different shutter speeds. A small round light will elongate with even a little motion blur, making it easy to distinguish this from other errors like bad focus.