Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon EOS dSLR

Reply
 
Thread Tools Search this Thread
Old Jul 8, 2009, 8:15 PM   #1
Junior Member
 
Join Date: Feb 2009
Posts: 10
Default Sharpness with XTi (400d) Question

I do not seem to be getting sharp pictures with the Auto setting, nor the AV or TV setting. When I use the Auto setting I have a 50/50 chance of a focused shot, but with the AV or TV settings I end up with soft focused. I have used all of the Focus Points and a selected few and I have even played with the Sharpness setting under the Picture Style Menu. I have used different lens (sigma 70-300 and the canon 18-55IS) and I have tried opening the pictures in Picasa and with the software that came with the camera, as well as in Gimp.

What am I doing wrong? I'm wondering if I should start shooting in RAW. I have heard that PP can fix a multitude of wrongs, but at what level does the picture just need to be shoot correctly? The camera is refurbished and I'm wondering if that has anything to do with it, or if it's just the shooter. haha I can take it, just tell me. haha

I have attached some pictures that I took on Monday with the 70-300 lens (maybe I'm trying to push it to far).
#4069, the focus was over the face and the AV setting was used
#4102, the focus was over the lady in the middle and the Auto setting was used.

Thanks! Chris
Attached Images
  
Waterwings is offline   Reply With Quote
Sponsored Links
Old Jul 8, 2009, 10:37 PM   #2
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,547
Default

Quote:
Originally Posted by Waterwings View Post
... I have used all of the Focus Points and a selected few and I have even played with the Sharpness setting under the Picture Style Menu.
-> That's your problem, the camera doesn't know what you want to be in focus!

In the 1st picture it picked the foreground (i.e. the blue T-shirt sleeve and the girl's hair) - BTW the shutter speed is also too slow for the focal lenght used

On the 2nd image the camera picked the arms of the two girls on the left and right instead

Last edited by NHL; Jul 8, 2009 at 10:52 PM.
NHL is offline   Reply With Quote
Old Jul 9, 2009, 7:55 AM   #3
Junior Member
 
Join Date: Feb 2009
Posts: 10
Default

But when I go back and look where the AF points were (with the camera's software):

In the 1st picture they were: on the boy's right ear, between his eye brows, top of his lip and top of his shirt on his right.

In the second picture they were: on the middle girl's nose, on her shirt (just above her clipboard), on her left sleeve (with a bit of the background), on the knot on the rope and on the girl on the left (on her shirt just above the letters).

I would have thought that with those AF points I would have been right on the mark.
Waterwings is offline   Reply With Quote
Old Jul 9, 2009, 9:10 AM   #4
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Were you using a tripod?

If not, the "rule of thumb" for reducing blur from camera shake is to use shutter speeds of 1/focal length or faster. Some people can hold a camera steadier than others, and some people may need even faster shutter speeds to prevent blur from camera shake. So, that's only a rule of thumb. The 35mm equivalent focal length should be used (multiply by 1.6 for a camera with a Canon APS-C size sensor).

Your first photo was taken at a focal length of 190mm, which translates to the same angle of view you'd get using a 304mm lens on a 35mm camera. So, to prevent blur from camera shake at that focal length, it would be a good idea to use shutter speeds of 1/300 second or faster. Your first photo was taken at 1/80 second without a flash. So, I'd suspect blur from camera shake to be causing some of the softness you're seeing. Also, at shutter speeds that slow, you can expect to see blur with any subject movement.

I see that the second photo was taken using a flash. However, it's a a bit too small to judge sharpness from. Was it cropped? If so, you may not have enough pixels representing your subject (and note that cropping will also make any blur from subject movement more obvious, since cropping is enlarging your view so that any movement is occurring across a greater distance for a given viewing size).

The brightness of the background on one side behind your subjects leads me to believe that you may be getting some ambient light exposure in that image using those settings (1/60 second at f/4 and ISO 400). IOW, the flash may not have been contributing enough to the exposure to freeze movement, and you may be seeing a bit of ghosting and blur from subject movement and/or blur from camera shake from ambient light exposure at shutter speeds that slow.

Also, you're shooting at wide open apertures (f/5 at 190mm for the first photo and f/4 at 70mm for the second photo). Note that most lenses are a bit softer with lower contrast at their widest aperture settings.
JimC is offline   Reply With Quote
Old Jul 9, 2009, 1:08 PM   #5
Junior Member
 
Join Date: Feb 2009
Posts: 10
Default

Thanks Jim! I just read an article last night about angle of view and I was beginning to wonder if I was trying to push the lens further than it was meant to go.

I was not using a tripod on either photo and the second photo was not cropped, but I wonder if the the subjects were just too far out of the flash's reach. I think it might be time to invest in a speedlite. :-)

I'm off to try your tips. Thanks!
Waterwings is offline   Reply With Quote
Old Jul 9, 2009, 1:28 PM   #6
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

Well, until then, if you can't use a tripod (or don't want to lug a tripod or monopod around), try to keep the potential for blur from camera shake (and subject movement) in mind at slower shutter speeds like that. Keep the camera as steady as possible, locking focus with a half press, then smoothly press the shutter button the rest of the way down at an opportune moment (trying to time the shots for when you have the least amount of subject movement). Listen for the shutter/mirror mechanism to open and close before releasing the shutter button to minimize blur from camera shake during the exposure.
JimC is offline   Reply With Quote
Old Jul 9, 2009, 2:08 PM   #7
Junior Member
 
Join Date: Feb 2009
Posts: 10
Default

I didn't think about waiting to hear the shutter open/close before releasing the shutter button, I'll give that a try.

Jim, if I may ask you one more question. While I was taking pictures on Monday, I think my flash blew a bulb, have you ever had that happen? I had the flash on, took the picture and out of the corner of my eye I saw a spark and smelled something burning for a moment and then it was gone. I've used the flash since then without any problems. Should I take a tiny screwdriver to it and open it up or let a professional take a look at it?

Thank you!
Waterwings is offline   Reply With Quote
Old Jul 9, 2009, 2:15 PM   #8
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

If it's working fine now, I wouldn't worry about it. If you open it up, you're more likely to let dust/moisture in, and I'm not sure what you'd accomplish by opening it up anyway, unless you're prepared to change the flash tube (and if it's working, why change it, especially if you don't have the parts and expertise). ;-)

If it quits working (or if you see that problem again), then I'd consider sending it to Canon.
JimC is offline   Reply With Quote
Old Jul 9, 2009, 2:19 PM   #9
Junior Member
 
Join Date: Feb 2009
Posts: 10
Default

Thank you so much!
Waterwings is offline   Reply With Quote
Old Jul 31, 2009, 3:50 PM   #10
Senior Member
 
Boldstar's Avatar
 
Join Date: Feb 2005
Posts: 241
Default

Don't forget, if you're seeing more than one focal point light up red in your viewfinder, the camera doesn't focus on all of them, just on the one it thinks is closest to you. Get out of the Auto mode and at least shoot in P. And set the auto-focus to the centre point. Focus and re-frame if you have to.

I don't know if I missed it above, but were you using a tripod? Especially at the 190mm length, I'd think a tripod would be absolutely necessary to eliminate camera shake. And don't forget, when using a tripod be sure to shut the image stabilization off if you're using an IS lens. The IS feature can create blur on a tripod because it's trying to compensate for hand movement that's not there.
Boldstar is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 4:40 AM.