Sharp images from a distance

J

jtrain75

Member
Hello peeps,
; I need some help and wondering if anyone has any suggestions. I shoot w/ a Canon 50D and primarily with a Canon 50mm 1.4 and a Canon 24-70 2.8 lens w/ external flash. I've been taking photos for families all year and close up to medium distance shots always come out tack-sharp, but if I have to fit in a large group or want to include the foreground and shoot from say 15-20 feet away, the images are not as sharp as I'd like them to be. I always shoot in aperture priority at 8.0 or with a shutter speed close or at 250.
; I'm thinking to try shooting with my tripod and a remote shutter to minimize camera shake which could be contributing to the images not being as sharp as I'd like. Anyway, let me know if you've come across this or have suggestions. Oh...and there is a Hoya uv filter on the lenses at all times.
 
Mirror lockup activated? ; The shutter speed seems fine and shouldn't be a problem....is the tripod shaking? ; That is a heavy lens and a not-so-heavy body with it....so the weight won't be over the tripod mount.

How much of the foreground are you trying to get in focus? ; You may want to focus at the hyperfocal distance....

http://www.dofmaster.com/dofjs.html
 
mirror lockup will not do much of anything at 1/250 sec. ; it's more for slow exposures (in the seconds).
one of your factors may be the quality of the glass that you are using. ; the 24-70L should be plenty sharp. ;

do you use single focus or AI servo? ; do you use center point focus ONLY and use the focus-recompose technique? ; that might help a bit. ;
 
is it possible you have a back/front focus going on with the lens??


i just purchased a lensalign tool recently, have calibrated 3 lenses so far, 24-105L, spot on, 70-300 f4.5-5.6 is, spot on, 50mm f1.2 L, badly back focused, needing -10 dialed in for adjustment. i believe your 50d has the microadjust feature. anyone who has a body with that available should make the investment in this tool
 
I'm not shooting on Autoservo, and I'm not sure about the backfocus problem. I'm not a big fan of the focus-recompose tecnique, I generally crop in post production or place the auto sensor over the focal point.

As far as hyperfocus goes, how can I utulize this technique? I figured with autofocus enabled that it do it automatically?
 
Sounds like you need to do a brick wall test. ; Find a brick wall and shoot it with various focal lengths, apertures and distances, using both manual and automatic focus. ; See which is the sharpest. ; To test for front or back focus, put three items in a diagonal line at varying distances, focus on the center one, and see which is sharpest.
 
Cropping in post could be part of your problem. ; Try focus/recompose. ; Remember at higher focal lengths, everything including shake and technique issues is literally magnified.

I doubt you have a focusing issue if your lower focal length pics are sharp.

(posted from my htc incredible via the tapatalk app)
 
thanks for the advice everyone! I'll see if it's a backfocus issue or simply a technique issue. I only crop to center the image or recompose the subject. ;
 
Lock your focus point on the center dot and don't ever take it off of there. ; It will simplify your life. ;

(posted from my htc incredible via the tapatalk app)
 
"Tim" said:
Try focus/recompose. ;
Click to expand...

Drrr hit the wrong button! ; This is okay except with certain lenses, like the 50/1.2 due to the curved field issue. ; Do that and the pics will be OOF. ; But I haven't heard of that problem with the 24-70.....
 
"Tim" said:
Lock your focus point on the center dot and don't ever take it off of there. ; It will simplify your life. ;

(posted from my htc incredible via the tapatalk app)
Click to expand...

I have mine (nikon) locked on the center spot, but with continous focus, so that as I recompose, the camera keeps moving the focus point accross the 51 different focus spots. I love this setting and method. it always works and really works with spot metering!
 
Roger, I am going on the assumption that very few people are toting the 50 f/1.2 and the ones who are know the limitations of it. ;

Craig, how can you use continuous focus and recompose without (usually) back-focusing? ; Continuous focus would try to lock on to whatever the center point is hovering over. ;

(posted from my htc incredible via the tapatalk app)
 
What Craig is saying is the 'red box' focus point actually stays 'locked on' to whatever is focused on initially. Once the shutter is released, it goes back to centered. It's a neat trick that saves time and eases frustration!
 
What mpower said. ;


And the only reason I brought up the focus/recompose issue is because there are lenses that have field curvature that affect the ability to do that. ; Maybe there is a problem with one of the elements in the lens, you can't rule that out....
 
gotcha! ; canons will constantly try to focus on whatever the focus point is hovering over as opposed to remaining locked on the intended subject, thus you will get a backfocused picture if you try to focus/recompose in most cases.
 
"Tim" said:
gotcha! ; canons will constantly try to focus on whatever the focus point is hovering over as opposed to remaining locked on the intended subject, thus you will get a backfocused picture if you try to focus/recompose in most cases.
Click to expand...

I wonder if the new AF module does this with Canon - Canon switched to using color to aid with AF tracking, not sure if it's in the 7D but definitely in the MkIV.
 
You must log in or register to reply here.
Back
Top