PDA

View Full Version : Need a critique...



~Carla~
02-08-2009, 11:58 AM
But not on my crappy shots.. lol! On the sharpness of this lens... this is my Sigma 24-70mm f/2.8 that I just bought. They don't seem tack sharp to me... what do you guys think? Should I take pics of something else with more detail? On a tripod??

Fully manual settings, hand held. I don't want to have to use a tripod every time I use this lens, so didn't use a tripod...

*none of them were edited at all. Straight out of my D90.

ISO:200

Pic 1 - 24mm

http://i285.photobucket.com/albums/ll53/justmystuph/003-4.jpg

Pic 2 - 36mm

http://i285.photobucket.com/albums/ll53/justmystuph/004-4.jpg

Pic 3 - 52mm

http://i285.photobucket.com/albums/ll53/justmystuph/005-5.jpg

Pic 4 - 70mm

http://i285.photobucket.com/albums/ll53/justmystuph/006-4.jpg

Is it just me with not steady enough hands? Or the lens? My other lenses seem much sharper than this one... blah.

jjeling
02-08-2009, 12:54 PM
First off, I do not know much about the D90 and do not know if it has image stabilization built in. Next to get a complete critique to help you out with your problems, the exif data from the images would help greatly. It would give a little technical information to give us an idea as to what was going on with the camera. With that being said, there are a few things noticed without needing that. The images are a little soft, and really noticeable in 3. Noticing that you used iso 200, im guessing you might want to up the iso setting for a faster shutter speed. The are probably soft due to a low f-stop, im guessing between 3.5 and 4.5.Also, the white balance looks slightly off. If there is one thing to force yourself getting in the habit of, its manually setting the white balance, it can make or break your image sometimes. You can see this was set on the couch or chair inside the house. Houses are notorious for not having enough light. Either turn all the lights on for more, or turn up your iso. You will probably have to do both. Make sure your white balance is manually set too. The contrast will greatly improve on this image(all you need is a white piece of paper, or use the card in this image. Just my .02 maybe that will help.

tirediron
02-08-2009, 02:28 PM
If you want to test lens sharpness, here's a quick and easy home method: Print a piece of paper with nothing but the letter 'X' in 12pt, upper-case. Tape that to a wall and set your camera on a tripod, ensuring that it is square to the wall and just inside the minimum focusing distance (wide open) of your lens; that is: If the lens has a minimum distance of 12" than set the camera so that the front element of the lens is 14-15" away from the paper. Use whatever light is handy (But not flash) to get a good, even illumination of the page, and then take a series of shots with the aperture wide open, mid-way, and stopped down at varying focal lengths.

Once you've got that done, look at 100% crops of the corners and center of each image and compare them.

~Carla~
02-08-2009, 02:43 PM
Thanks, guys!!!

Going to try the "X" test! :D

mindforge
02-08-2009, 03:56 PM
Lens looks fine. You got part of that card (upper left) in great focus. Wide open aperture is causing the blur. Take the shot again, with a higher f-stop.

Ben H
02-08-2009, 05:38 PM
THat's what I thought - looks more like user error - user error is the number 1 cause of blurry or out of focus pics. The ribbon parts are in focus, and as they are nearer the camera, I think what's likely to have happened is the camera is focusing on something other than what you intended to focus on.

Are you running in automatic autofocus point selection, or with one manually selected point?