Wide angle sharpness/focus/DOF problem, any pointers?

[bzollinger]

Hello,

I'm a proud new owner of a Canon 10-22mm lens. So far I love it but there has been a learning curve. Mainly I seem to have a hard time getting the DOF right so that the picture appears in focus satisfactorily. I've read all about hyperfocal concepts and various articles on UWA shooting.

This weekend I took this picture and thought that I had calculated the scene properly only to find out that the top half of the frame is OOF. It is an HDR exposure so I'm only linking to the 0 EV shot.

Here's how I set it up:

*tripod mounted about 5 inches about the ice/ground
*used live view to compose image
*manually focused aprox. 1.5-2ft. away
*f/16 (smallest f/stop for sharpness on my 10-22mm)
*2-sec timer
*AEB for +-1 & +-2

What did I do wrong? I ran this through my DOF calculator after taking it and according to it I should have been good to go? Why are the tress so blurry?

I'm ready to learn and tackle the challenges that the UWA lenses present, but I need a nudge in the right direction from someone with some insight and experience.

thanks for any and all input,
Ben

<img src="http://farm4.static.flickr.com/3331/3544963862_49663a1860_o.jpg" width="640" height="960" alt="Denali UWA" />

For some reason I can't embed the photo from Flickr? I've tried different sizes form different computers, but still it won't embed. Oh well the link works.
http://www.flickr.com/photos/38390791@N08/3544963862/ (http://www.flickr.com/photos/38390791@N08/3544963862/sizes/o/)

[bzollinger]

Also the shutter speed was 1/4. So a little slow, but with the timer and the tripod I figured it would be fine. Especially since the foreground is so sharp.

Anyone have some input?

thanks,
Ben

[bzollinger]

Finally got the image embedded!

Take a look at my posts and this image and see if you can give me any pointers on what I might have done wrong.

thanks for your help and expertise!
BZ

http://alaskanphotographs.com/20090516-IMG_2529.jpg

[ccookdo]

I am only a rank beginner, but it looks to me that you have an image with dynamic range (span from brightest to darkest) that exceeds the camera's ability to record. The sky is blown out, and the darkest part of the foreground is quite dark. You would be better served to take two images- one for the brighter areas, and a second for the darker foreground, then combine them.

[bzollinger]

Agreed this photo is one of six, I used 5 for an HDR, but when I combined them I couldn't go any further because of the out of focus trees and/or the limited depth of field. I've used this photo in this thread becase it was EV 0 and demonstrated the DOF problem.

I'm trying to figure out how to use the 10-22mm lens better so that the entire picture is in focus. Did I focus too closely? Was f/16 too low should I have used f/22? Was there any way that I could have done this differently to ensure that everything was in focus?

thanks,
Ben

[argyle]

I'd be willing to bet that you're seeing the effects of lens diffraction, which on a 1.6 crop camera begins to rear its ugly head at apertures of f/16 and smaller.

[bzollinger]

I'd be willing to bet that you're seeing the effects of lens diffraction, which on a 1.6 crop camera begins to rear its ugly head at apertures of f/16 and smaller.

Hummmmm... I think you might be on to something. I'm reading a little more about lens diffractoin and trying to find specifics to the 10-22mm.

So if that's the case then in theory I cound have use an aperture of say f/11 and got more DOF, and less diffraction?

thanks for the suggestion, I'll have to continue to look into this and possibly do some testing.

Ben

[argyle]

Give it another shot...try an aperture somewhere around f/11 or f/13. Also, be mindful of the time of day...try to shoot around the golden hour when the light is nowhere near as harsh.

[RDKirk]

A quarter second is quite slow--slow enough to show the effects of any breeze. If you didn't use mirror lock up, that's also going to significantly affect sharpness at 1/4.

Diffraction effects is overblown in most cases. I suspect breeze and camera vibration.

[bzollinger]

Give it another shot...try an aperture somewhere around f/11 or f/13. Also, be mindful of the time of day...try to shoot around the golden hour when the light is nowhere near as harsh.

I wish I could take this shot over again. We were in Denali 300+ miles north. But I will try more shots with wider apertures. And until I figure it out I'll take several shots with different f/stops too. Don't know why I didn't think of that then...:rolleyes: it's not like I ran out of film or anything!

Also the time of day point is well taken. This was hours after sunrise and even further from sunset. My expectations shouldn't be very high if the light is not great!

Thanks for the input! It helps me work through possible issues and come up with possible solutions.

[bzollinger]

A quarter second is quite slow--slow enough to show the effects of any breeze. If you didn't use mirror lock up, that's also going to significantly affect sharpness at 1/4.

Diffraction effects is overblown in most cases. I suspect breeze and camera vibration.

This could definitely be the case. And by opening up to f/11 or f/13, and maybe increasing the ISO to 200 I could easily produce faster shutter speeds.

This is a good point that skipped my mind while composing this shot. Just because I'm on a tripod doesn't mean that it'll be sharp!

I used to be in the habit of using mirror lockup and should start again. That did cross my mind but because the surface was icy I thought that the less I actually touched the camera the better.

If only the Xsi would take 3 consecutive shots in burst mode, using AEB, w/ mirror lock up! Do any of Canon's bodies do this?

thanks for pointing out some very important fundamentals that I should always be thinking of.

This forum rocks!!:razz:8-):cool::D:-P

[argyle]

This could definitely be the case. And by opening up to f/11 or f/13, and maybe increasing the ISO to 200 I could easily produce faster shutter speeds.

This is a good point that skipped my mind while composing this shot. Just because I'm on a tripod doesn't mean that it'll be sharp!

I used to be in the habit of using mirror lockup and should start again. That did cross my mind but because the surface was icy I thought that the less I actually touched the camera the better.

If only the Xsi would take 3 consecutive shots in burst mode, using AEB, w/ mirror lock up! Do any of Canon's bodies do this?

thanks for pointing out some very important fundamentals that I should always be thinking of.

This forum rocks!!:razz:8-):cool::D:-P

Invest in a remote shutter switch and you'll pretty much never have to touch the camera. :D Also, when using mirror lockup (MLU), be sure to wait a few seconds after flipping the mirror before firing the shutter...this will allow any vibrations to dampen out.

[jsinon]

Invest in a remote shutter switch and you'll pretty much never have to touch the camera. :D Also, when using mirror lockup (MLU), be sure to wait a few seconds after flipping the mirror before firing the shutter...this will allow any vibrations to dampen out.

I would add to look on ebay for a knock off. I bet my $10 Phottix remote(wired) does the same thing as the $40 Canon one and the quality seems pretty good. The only down side is if you are in a hurry to get it. It took about 2 weeks to arrive from Hong Kong. But for around $10, shipping included, I was willing to wait.

[bzollinger]

Invest in a remote shutter switch and you'll pretty much never have to touch the camera. :D Also, when using mirror lockup (MLU), be sure to wait a few seconds after flipping the mirror before firing the shutter...this will allow any vibrations to dampen out.

:o You mean the wireless remote shutter that was sitting in my camera bag 100 ft away? ;) It's more and more clear that I didn't take the time or care to really make this a great shot.

I'm determined to try again and to do everything to increase my chances of a 100% sharp frame at 10mm!

[argyle]

:o You mean the wireless remote shutter that was sitting in my camera bag 100 ft away? ;) It's more and more clear that I didn't take the time or care to really make this a great shot.

I'm determined to try again and to do everything to increase my chances of a 100% sharp frame at 10mm!

Yep...that's the one.

[timeasterday]

The sweet spot of that lens seems to max out around f/8. Anything above that and you start to lose quality. You were at 10mm so you only need to focus out about 1m to everything to infinity in focus. As you move up the zoom range you need to focus slightly further out, but still not much. Focusing 1-2ft out may not have been enough. I prefer to be a little past that hyperfocal point sometimes.