Need Advice

[tonyr0584]

This pic was taken with Rebel EOS and Sigma 17 - 70 DG EX F2.8
Shot at ISO100 f2.8 How can I get the pics to be sharper. Or is there some test I can do to make sure there is not something wrong with the lens.

[Tommy]

Couple things you can do::

1) stop the lens down. Maybe around f/5.6 if you can. Every lens has sweet spot where it's the sharpest, and it's usually right around that spot. Take a bunch of test shots of the same subject at different apertures to find your lenses sweet spot.

2) add a little sharpening in PS.

Hope this helps. ;)

[tonyr0584]

So is it because of being opened up to f2.8? These were taken around 6:30pm. Sun going down behind trees.

[Tommy]

it's possible. Like I said, just take some test shots to verify the sharpness of your lens and different apertures. ;)

Also, what was your shutter speed? Camera shake can also contribute to getting photos that are not as sharp as they can be...

[elbirth]

judging by the exif data on the picture, the shutter speed should have been high enough (1/640) to prevent slight camera shake in that shot, so I'd say it'd probably mostly just the fact that you have the lens wide open at f/2.8. Bump up the ISO and stop the aperture down a little and see how things work out

[tonyr0584]

test mode...... thanks guys

[mcmadkat]

From your EXIF you were getting a ss of 1/640 @f2.8

If you stopped down to f5.6 that would still give you 1/320 or at f8 1/160 ish.

Best try try playing with the lens a bit. That pic looks too soft for even f2.8, maybe the JPEG compression has killed it a bit.

[tonyr0584]

good info.... thanks. the raw image looked pretty much the same as the jpg. i'm thinking the fstop. will test at different settings. thanks.

[adam75south]

could just be a misfocus...even at f/2.8 it shouldn't be that soft. do you have any more from that day at f/2.8?

[tonyr0584]

yep.... here is the followup shot to the first.

[hawk911]

Even at iso 200, you should be able to stop the lens down a bit and still shoot handheld with no camera shake. How far from the subject were you, and what's your focus mode set to? Are you center focusing, or full?

[tonyr0584]

Approx. 15ft from subject....... Center/Full..... good question. I'm a little lost on that one though. My focal point is centered. Can I change that in the camera?

[bacchanal]

yep.... here is the followup shot to the first.

That exif can't be right it says f/2.8 at a FL of 70mm. Wouldn't the maximum aperture be 4.5 at 70mm? Or is it just stating the max aperture of the lens?

[tonyr0584]

Shooting in manual mode. This lens does let me set f/2.8 for 70mm.

[elbirth]

That exif can't be right it says f/2.8 at a FL of 70mm. Wouldn't the maximum aperture be 4.5 at 70mm? Or is it just stating the max aperture of the lens?

The EXIF says he shot the picture with the Canon 28-70mm f2.8L lens. On higher-quality lenses that only state a single f-stop, it means that the entire focal range of the camera can achieve that aperture. So no matter what focal length the lens is zoomed to, it can open up to f/2.8. Similarly with the 70-200mm f/2.8 (or even f/4), etc.

And generally speaking, EXIF data is very accurate. In fact, it should be trusted over the person taking the picture (say they claim to have taken a really great, noise-free shot at ISO 3200.. but the EXIF shows they're lying or otherwise forgot the exact setting and it was in fact only at ISO 400 or something).
EXIF data can be manipulated... but in this case, he's looking for help, so I highly doubt that's the case

[laurielozano]

From my experience of taking blurry pics like that (and I've taken ALOT of them), I always thought maybe it was my lens or something. But to my dismay, I've discovered that my lenses are fine, I'm the problem. :( From reading these forums and checking out everyone else's postings of super sharp shots, I'm learning that if you bump the ISO to 400 in these situations, you'll get a sharper shot as well as faster shutter speeds. At 100 and 200 even the slightest camera shake will be evident. Took me a long time to learn that one! Try using iso 400 (especially at that time of day) and you will notice a great improvement.
Keep practicing and keep reading these forums. you'll learn alot and be amazed by the outcome. I'm still waiting for my son's baseball next game so I can apply what I've learned, but they keep getting rained out. Hopefully I'll get a chance tomorrow!

[Kristy]

It's really hard to get super crisp shots when the lens is wide open... I've been practicing, and my limit seems to be about 3.5... I get lucky at 2.8 somtimes, but more often not... So if your not just practicing and want a "keeper" be sure to keep you aperature above 3.5 and Shutter above 1/125 that should be a good rule of thumb. :) Happy Shooting!

[laurielozano]

Thats a good shot, even though it is a tad soft. If you crop it, so that its just the little girl and boy and then apply the Unsharp Mask filter in Photoshop at amount=20%, Radius=60.0 pixels, and Threshold=0, it will look sharper.