7D focusing question??

[maharzan]

Thanks awinphoto. Looks like that will be my last option. I will keep practicing manual focus till then. I do use AF points just not that AF mode in the lens. Not many pros use AF I suppose. I used to use the Live View but it ate lot of batteries and I came to know later that many pros actually use viewfinder just like old times. I switched to that later. If it doesn't work, well, I will just stick to Live View.

 

[Admin US West]

It sounds like you have your camera set to autofocus with AI-Servo and are using the manual override to focus. Then, as soon as you half press the shutter, your autofocus takes over and changes the focus point.

Be sure you have the switch on the lens set to manual focus, mount the camera on a sturdy tripod, use liveview at 5 or 10 X, and focus on the point you want to be sharpest. You are seeing the actual image on the LCD, so what you are seeing is what you will get.

 

[awinphoto]

It sounds like you have your camera set to autofocus with AI-Servo and are using the manual override to focus. Then, as soon as you half press the shutter, your autofocus takes over and changes the focus point.

Be sure you have the switch on the lens set to manual focus, mount the camera on a sturdy tripod, use liveview at 5 or 10 X, and focus on the point you want to be sharpest. You are seeing the actual image on the LCD, so what you are seeing is what you will get.

No, what i got from his post was his lens was on MF however the AF in camera is still active, so the point(s) he has his AF set to will beep when the MF "hits" the focus point, however doing that for percise focusing is not very accurate because of the human element of not completely stopping when the beep sounds... even a fraction of a second delay from the beep sound to when your fingers stop turning the focus dial, it will show OOF even though you got the focus confirmation.

maharzan, I'm a pro and I use AF most of the time. The only time I use manual focus, to be honest, would be product shots, or professional commercial shoots where I trust the model to hold still enough so I can get focus using live view. Even with that, with people i'm sure you know when zoomed in 10x the slightest flinch or movement within your subject can screw up your focusing.

The 7D was praised because it was a great stride on Canon's behalf on catching up and in some reviews, beating nikons AF system on the nikon D300s. To disregard the AF all together, on this camera, would be like buying a top of the line video HD camera and shooting at SD. Plus, any mis-focus will be even more dramatized because of the high MP. Focusing in the viewfinder was a common practice with early DSLR's and film cameras, however you cant really do that anymore because of the medium.

 

[Loswr]

It sounds like you have your camera set to autofocus with AI-Servo and are using the manual override to focus. Then, as soon as you half press the shutter, your autofocus takes over and changes the focus point.

No, what i got from his post was his lens was on MF however the AF in camera is still active...

Focusing in the viewfinder was a common practice with early DSLR's and film cameras, however you cant really do that anymore because of the medium.

I had the same initial thought as Scalesusa (and hoped the lenses being used like that had FTM, even though it's still not a good idea to manually focus while the AF motor is active). But I think you're right - MF set on the lens trumps AI Servo mode on the camera, and in that case a focus confirmation beep would sound.

maharzan, I do really think you should practice with and start using autofocus. Awinphoto is correct that manual focusing is difficult to get right with current dSLRs, and as I pointed out above, the focusing screen on your 7D will not give accurate results for manual focusing in the viewfinder at apertures wider than f/2.8.

 

[maharzan]

Thanks for all the posts you guys are making. Its helping me. Yesterday, I had to go shoot my cousins marriage. Like I said I am no pro, and I occasionally use my came, if not at all for some months. This time I used Auto focus fully. It takes so much time to manual focus.

I took around 600 images but threw out 200 of them, blurry and unwanted images. Most of them seems to be pretty sharp but due to low light inside, I had to bump up ISO / lower Shutter speed at 2.8 and 3200/6400 ISO were very grainy. I will never shoot at these ISO. I am using a 17-55mm f2.8.

With few same position images I shot, like I said before, even in AF, I got one sharp image out of 3 or 4 shots. I am posting this particular shot as it seems to describe the problem I am trying to explain. The 'sad' face was perfectly in focus but the 'smiley' face is not, which is pretty bad as I took like 3-4 of these shots and all smiley faces weren't at 100% focus.

 

[maharzan]

Note, when not zoomed 10x in the LCD, they look absolutely great.

 

[awinphoto]

Note, when not zoomed 10x in the LCD, they look absolutely great.

From what you were describing earlier with your keep rate, I'm glad to see the percentage go up overall. With that second "smiling" photo, on my iPhone it was kinda hard to see if the lens kinda backfocused cause some of the hair seemed in focus but not the eyes. Do you chimp the shots during the shoot? (review pictures and zoom all the way in after the picture was taken) to see if they are in focus? It kinda slows you down a bit however it zooms you in deeper than live view can and you may get a better idea on focus (however the monitor screen will be the final judge). What aperture were you shooting at? 2.8? 4? Just curious. Regarding the low light, that's a constant battle for working photographers on a daily occasion. There's good plug-in for photoshop if you have photoshop. Speaking of post production, sometimes you can underexposed upwards to 2 stops you can bump up the exposure in post however I would leave this as an exemption to the rule. Sometimes the grain will be lower that way rather than the pure digital noise by the camera.

Keep practicing with af, use selective af rather than full zone af or 9 point af. The 4-5 point sometimes can be hit or miss depending on the depth of the subject/face/whatever. I would use primarily single point or the spot single point to nail focus however they can be tough on constantly moving subjects. Keep working at it and good luck. Feel free to email me if you keep having problems or questions.

 

[maharzan]

Yes, Its very hard to see the difference in the LCD in day time. I reviewed 2-3 times to find that the difference. Took another shot and that was also out of focus (similar), I couldn't ask them to sit there for more that 5 shots you know.

1st: ISO 200, 55mm f2.8 1/1000
2nd: ISO 200, 46mm f2.8 1/1000

These photos were taken outside, so no low light here. I am just using 2.8 as I love it. hehe.

Looks like it front focused. I see her few hairs are focused, nothing else in that 2nd photo.

I use single point AF with that rectangle and move around to focus particular object.

 

[bvukich]

Looks like it front focused. I see her few hairs are focused, nothing else in that 2nd photo.

I use single point AF with that rectangle and move around to focus particular object.

It definitely looks like it front focused. Maybe 1.5-2", I bet her left shoulder is in focus.

 

[maharzan]

Yea, its a bit frustrating to not have a 'great' shot perfectly focused. Any tips on overcoming this?

 

[unfocused]

My personal opinion is that this is a depth of field issue. One shot in focus, one shot just slightly out of focus. Or more accurately, one shot slightly mis-focused.

I note that you were shooting wide open (2.8 at 1/1000) I'd bet that if you shot it at 1/250th at 5.6 her entire face would be in focus. It's hard to get autofocus perfect since the camera has to pick something to focus on and the camera can't really tell the difference between a nose and an eye. Practicing will help, but under real-world conditions, it's still hard to get it perfect every time.

Good news is that the only person who will notice will be you and only when you pixel-peep. Give them a print and it will look perfect.

One way to feel better about this problem. Go take a look at Robert Frank's "The Americans" and see how many of his pictures were tack sharp. Didn't stop him from producing what may be the most significant photo book of the 20th century.

 

[Orangutan]

My personal opinion is that this is a depth of field issue.

Agreed. You need to perform basic tests for front/back focus to assure yourself that there's nothing wrong.

Can anyone suggest a good testing methodology? A quick Google search yielded two:

http://www.focustestchart.com/focus21.pdf
http://www.leongoodman.com/d70focusnew.html

They're written for Nikon, but should work fine for your 7D.

 

[maharzan]

Cool.. I will keep practicing and see where I get to. Thanks again all of ya.

 

[Admin US West]

You will find some good ideas and a workable autofocus microadjust chart here.

http://regex.info/blog/photo-tech/focus-chart

Be sure to read the article first, understanding how the test chart works with your camera will help you get the best results. One of the many things to think about when testing autofocus is knowing exactly where your camera is going to focus. Unfortunately, some test charts cause people to have difficulty because their camera may not focus in the right spot. Then, we here complaints about erratic focus.

Focus can definitely be erratic, but make sure its not the test chart or subject causing it.

 

[chriswatters]

When using a lens with a large aperture, and therefore a shallow depth of field, I have gotten similar results when my camera (a T2i) is set for One Shot AF. I suspect that my problem is that I do not fully release the shutter between shots. Any small change in distance can put the subject out of focus. Adjusting the zoom can also affect focus. Because the camera has already locked focus, it does not refocus until I fully release the shutter. To solve this problem, I either use Servo AI or make sure that I fully release the shutter between shots.

 

[Admin US West]

When using a lens with a large aperture, and therefore a shallow depth of field, I have gotten similar results when my camera (a T2i) is set for One Shot AF. I suspect that my problem is that I do not fully release the shutter between shots. Any small change in distance can put the subject out of focus. Adjusting the zoom can also affect focus. Because the camera has already locked focus, it does not refocus until I fully release the shutter. To solve this problem, I either use Servo AI or make sure that I fully release the shutter between shots.

Using a tripod will help immensely. You are trying to get the sharpest possible image, so any movement at all should be minimized.

 

[chriswatters]

Using a tripod will help immensely. You are trying to get the sharpest possible image, so any movement at all should be minimized.

A tripod might help in many situations, but it would be counter productive in mine. Most of the motion is on the part of the subject, and that requires more mobility on the part of the camera. 7 month old badies don't sit very still, even when you ask them nicely.

Shutter speed is effective in freezing motion in the X and Y directions. The focus problems comes from motion in the Z direction. The methods that I mentioned seem to be helping in my case, but I am open to other suggestions.

I also realize that the problem could be avoided by increasing the depth of field, but an out-of-focus background is also desirable. Compromises must be made. Improvements in technique help in balancing those compromises.

 

[maharzan]

Yea I have tried micro adjusting only to later disable it all. It seems to focus right. The only thing I am concerned is sometimes it focuses great sometimes not. And then, I have to yet to get sharpest of images like I see on flickr or other forums with the same gear/settings. I guess people use more lights. Thats the only thing I think I am missing.

 

[justsomedude]

The only thing I am concerned is sometimes it focuses great sometimes not. And then, I have to yet to get sharpest of images like I see on flickr or other forums with the same gear/settings.

Welcome to the world of the 7D. See my post here. And these articles here, and here, and here, and here. Then cry when you realize you're outside of your return window. But there's always warranty service if you want to start down that road.

Best of luck on your search for 7D sharp focus.

:'(

 

[Admin US West]

The only thing I am concerned is sometimes it focuses great sometimes not. And then, I have to yet to get sharpest of images like I see on flickr or other forums with the same gear/settings.

Welcome to the world of the 7D. See my post here. And these articles here, and here, and here, and here. Then cry when you realize you're outside of your return window. But there's always warranty service if you want to start down that road.

Best of luck on your search for 7D sharp focus.

:'(

I've heard others comment about the accuracy of focus for the 7D. I did not have the issue with mine once I learned to use it, but at first, half my images were out.

Still, it seems that others see the same issue.

Here is a link to some analysis. The data used for the analysis is pretty thin, and carrying out a analysis based on a trickle of data is a bit suspect, but, there may be something there.

For the most part, the data shows that the lens and not the camera determines accuracy of focus.

http://nikonrumors.com/2011/03/28/auto-focus-accuracy-a-scientific-cross-brand-analysis-guest-post.aspx