Help with soft focus

shootin'mom

I have done a number of group shots and am having problems sometimes with the sharpness of the image. I am shooting with a Canon 30D and Canon 24-70mm 2.8 USM lens. When I do individual portraits and studio shots, I have no problems...sharp as a tack. But when I move back from my subjects to shoot a group of people, it seems that I am losing quality. Is this simply a function of distance? I have attached a couple (#1 & 2)for review where I was dissapointed with the focus and also another (#3) that was taken from a similar distance that is clearer. Any ideas why I'm having this trouble? Should I be manually focusing? I am hand holding. Should I be using a tripod even though the shutter speed is not terribly slow?

#1

Exposure Time 0.004s (1/250)
Aperture f/4.0
ISO 250
Focal Length 30mm (48mm in 35mm)


#2

Exposure Time 0.0012s (1/800)
Aperture f/3.5
ISO 400
Focal Length 32mm (51.2mm in 35mm)


#3
Exposure Time 0.0031s (1/320)
Aperture f/4.0
ISO 200
Focal Length 38mm (60.8mm in 35mm)

Sometimes it's almost as if the focus is off...the background is in focus and the subject is not...even though I have clearly positioned the focus dot on the subjects. Any ideas?

I post-process in Lightroom. But I haven't really done much to these that I think would affect them.

Thanks. Tanya

photogmomma

Can you post your EXIF information? Thanks!

Also, your last photo is quite nice, but the color is way off... Just so you know!

I think that seeing the EXIF is important, though....

(As a side note, I have the same lens and have used it on my 30D without problems.)

jeffreaux2

It could be caused by any number of things, but that combination of lens/camera should produce good results.

I tried to find these photos in your gallery to view the exif info, but they are all locked down or either in hidden galleries. I would have been looking at aperature. I wouldn't reccomend using anything larger than F 3.5 for a photo of a couple. In my experience at F2.8 one of the two people will invarably be soft. For large groups I would probably prefer F5 to F8....just to be sure. That is not to say I have not gotten decent results with a larger aperature opening, but it is safe.

Now to the handhold. To find out if there is a calibration problem with a lens, yu will need to eleiminate the possibility of camera shake. I use a monopod religously, but reccoment you try some test shots with a tripod, or use a tripod for awhile on all of your group shots. The monopod has greatly helped my keeper ratio.

Focus mode. If you are in AVServo, and focus, then recompose the camera with focus on the BG if the focus point falls off your subject. I one shot mode unless shooting moving subjects......walking or running.

Do you use the center focus point or all of them? It is my understanding that at least on my camera the center point is more sensitive and I use center point only........focus, recompose while half depressing shutter, and shoot.

Contrast- the camera will focus best on an area of high contrast. Normally in people photos we focus on the eyes. But in group shots especially if you are insuring DOF by using a smaller aperature, it is possible to choose a different area to focus on to get a good contrast point for the camera. A shirt collar meeting the neck, dark hair nect to skin, a light shirt tucked into dark trousers.

Shutter speed. 2X the focal length is a safe number....especially if using a monopod.

Lastly the lens could need adjustment. This would require sending it to Canon for calibration. Before making this determination you should probably perform some tests with it. Here is a link to a decent article by a nikon owner, that includes a downloadable focus test chart.

shootin'mom

I added the exif information below the shots.

Yes, Jeff, I agree with you on using a smaller aperature for groups, although in these 2 top shots, the group was pretty much all about the same distance from the lens, so I used a little larger (4.0 & 3.5). However, I don't think that's the problem, because nothing is in focus. It's making me crazy! I do use center focusing almost all the time. I focus on the subject and then reposition. I use One Shot mode religiously. What's weird is that I can take a succession of shots and some are fine and then others are off. I'll consider that monopod idea. I have a wonderful new one to use with my 100-400mm for sports shots, so it will do the job, I'm sure! If you'd like to see others in the Gregg gallery, the password is Fleet. I had a time with the group shots, but the individuals are really crisp. I'd appreciate your feedback on them.

Thanks for the word on the color, Andi. This was a sunset shot, so there are definitely a lot of yellows in the skin because of that.

Thanks to both of you for taking time to respond. Any other thoughts are more than welcome.

jeffreaux2

What's weird is that I can take a succession of shots and some are fine and then others are off. I'll consider that monopod idea.

If by that you mean a succession of shots in continuous shutter( rapid fire) mode without refocusing in between shots then camera shake is a likely culprit. I use a HEAVY monopod with a ball head to aid in composition/ camera angle positioning. Most people use a tilt only head, but I like the flexability of the ball head. It took some time to become comfortable using the thing, but It is all second nature now. I usually leave the ball slightly loose so I can focus/ recompose as you do, but let the weight of the camera rest on the monopod. I only tighten the head when walking around so the camera isn't flopping all over the place. If you already have a monopod it will be cheap to try it out that way. There are many types of ball heads out there, but I use a medium sized Manfrotto/Bogen 486RC2 and it supports a surprising amount of weight. You don't need a panning knob for a monopod since the pod itself can pan by simpli turning it on it's foot.

Good luck, and keep us posted on what you come up with.

shootin'mom

I don't typically rapid fire, because I do focus and recompose. But I am thinking shake could be it. Not sure why I don't have the problem on the closer shots though. My Manfrotto monopod is the 685B with the 3229 tilt head, not the ball head. I'll see what I can do and consider the ball head as well.

landrum

I have the same problem with focus! I shoot with a 30D and 28-135mm f/3.5-5.6 IS. I always use a tripod and trip cord, as my subjects are mostly families and small children. I typically have all focus points set, because I seem have worse luck with just the center focus point when I'm not recomposing each shot.

Shooting successive shots are not consistant with focus or even exposure...even when the exposure is set manually. I do not rapid fire, but shoot a single frame at a time.

My close ups are crisp and perfectly clear, but my wide angles are usually soft. It seems to be focusing on the background a lot of the time.

Have you figured out any solutions to this? Am I missing a setting somewhere?

jeffreaux2

landrum wrote:

I have the same problem with focus! I shoot with a 30D and 28-135mm f/3.5-5.6 IS. I always use a tripod and trip cord, as my subjects are mostly families and small children. I typically have all focus points set, because I seem have worse luck with just the center focus point when I'm not recomposing each shot.

Shooting successive shots are not consistant with focus or even exposure...even when the exposure is set manually. I do not rapid fire, but shoot a single frame at a time.

My close ups are crisp and perfectly clear, but my wide angles are usually soft. It seems to be focusing on the background a lot of the time.

Have you figured out any solutions to this? Am I missing a setting somewhere?

I exchanged a couple emails about this post with "shootin mom". What wasn't mentioned in her original post was that she had been using a B&W UV Filter on her lens. Her focus issues disappeared after ditching the filter.