Help with fixed lens.

[cyberphotogs]

Hi there,

I just purchased a 50mm fixed lens for my Canon 30D. I am having a bit of trouble getting used to this lens. Especially in low light situations. Can someone explain to me how I should be tweaking the camera settings for this lens. Indoor and outdoor shots. Maybe you can point to a tutorial on this?

Thanks and I look forward to your reply.

...Bruce

[OsmosisStudios]

the 50mm is special in that it opens up to 1.8 (or 1.4 if you splurged on the more expensive model). If you work in aperture priority, set the aperture to 1.8 and experiment. You'll find that you'll be able to use it in really really low-light situations because it lets alot of light in. It'll also allow you to do great portraits: its sharp and at 1.8 has fantastic blur in the backgrounds.

[cyberphotogs]

Hmm. when i tried to do this I noticed my photos were not all that sharp. why would that be. Bit of camera shake??? Not sure. Let me know your thoughts.

[inkista]

There are two possibilities:

1) camera shake. You'll notice a sort of smear or multiple-image effect if it's camera shake. The rule of thumb for eliminating camera shake is to use a shutter speed of 1/focal_length or higher (so, in this case, 1/50s), so if you were shooting at a shutter speed of less than 1/30s, it's likely to be camera shake.

While you can use an f/1.8 for available light shooting, in low light, you may still need to increase the iso to get high enough shutter speeds.

Make sure you know how to hold your camera.

2) misfocus because of the thin depth of field.

This is also all-too-possible with the 50mm f/1.8, where the autofocus performance can be a little wonky. First thing to do is open a fuzzy shot in the Canon software, and see which focus point was used. If you had matrix AF turned on, the camera may simply have chosen the wrong focus point.

Learn how to set the camera to use only a single AF point. Most folks use the center point, and then learn to half-press and recompose to set the focus. That technique may not work so well with a depth of field that's only inches deep, but it can get you closer to the ballpark.

Also, the autofocus system works on detecting contrast, so aiming for edges where dark meets light an help boost it. Make sure when you look through the viewfinder that the AF has actually done its job, before taking the shot.

And you can always try flipping the switch on the lens to manually focus.

[Wynder]

If you're able to shoot portraits on a tripod, absolutely do so -- that's step one to getting rid of shake and getting those tack sharp photos. If you're on a tripod, you'll also want a remote shutter release. And, if you're able to use a shutter release, be sure to enable mirror lockup (in the custom functions) to help reduce vibration even more.

I've found that my 50mm at f/1.8 has a *very* narrow depth of field, to the point where when filling the viewfinder with my subject's face, I would get one eye in focus and the other out... great if you're going for that effect, but using a single focus point and focusing on the eyes did wonders once I closed the aperture a few stops.

If you're unable to shoot on a tripod, you have some great suggestions above. The more light the better to shorten those shutter speeds... I *really* hate using the flash, especially the build in flash, but I recently picked up the Gary Phong Puffer diffuser which softens up the light quite a bit and makes for faster speeds. If you find that you're still not able to get fast shutter speeds, don't be afraid to crank the ISO up to 400 or so to see if that helps... I've shot at 1600 on my XSi in a darkened pub with great results.

[Samanax]

Which 50mm lens do you have? The EF 50mm f/1.8 "Nifty Fifty" is known to hunt focus in low light situations. The EF 50mm f/1.4 USM lens is better in low light situations. Neither lens has Image Stabilization so use a shutter speed 1/50 or faster to keep camera shake to a minimum. Of course use proper camera holding techniques (two hand with elbows tucked in and breathe slowly and smoothly). Or use a tripod with a remote shutter release.

What kind of settings are you currently using? What shooting mode are you using?

And do you have any sample pictures to look at? Seeing a picture is much more helpful than you trying to describe the problem with words.