Should I use the 75-300mm or 18-55mm for portraits

gregspix

I recently purchaced a new Canon Rebel T2i, my first challenge with a DSLR, and it came with an 18-55mm and a 75-300mm zoom. I thought my 75-300mm lens would be great for shooting portraits given that it should super focus on the subject and blur everything else beyond the main subject. I'm finding this not to be true, getting way too much grain and noise and just very cruddy photos. Would it be best to drop this lens and go back to the 18-55mm for portraits, or are there just adjustments to the camera I need to make with the 75-300mm?

Moose

Howdy @gregspix - In order to capture a shallow depth of field (small area in focus), it's best to use a lens that can obtain an aperture between f/1.2 to f/2.8 . Lower apertures allow you to focus on a subject and blur everything else into oblivion. As an added benefit, they also enable you to use faster shutter speeds at lower ISO's which equals, sharper shots with less image noise.

Both of your lenses aren't capable of getting apertures that low. The 18-55mm can only go down to f/3.5 at 18mm and f/5.6 at 55mm. The 75-300mm can only go down to f/4 at 75mm and f/5.6 at 300mm.

In addition to the depth of field, you also have to keep the ideal portrait focal range in mind. When you shoot wider than 35mm, features don't look right (large noses). When you shoot longer than 150mm, faces start to look flat.

Between your two lenses, it would be best to shoot with your 75-300mm lens and set the aperture to f/4. You can do this by enabling Aperture priority (Av on the mode dial) and rotating the command dial to obtain an aperture of f/4.

If you're in the market for a new lens, just give me a ballpark budget and I'd be glad to point you in the right direction. Happy shooting! :)