sunglasses and focus

joshhuntnm

I took this picture of Dawson, experimenting with various reflectors. I am pretty sure I focused on the sun glasses. I you look at this at 100% (gallery address below) you can see to focus is closer to the ear. I am wondering if the shiny nature of the sunglasses threw the focus off just a bit. Has anyone seen this? The apeture is at 3.2.

http://joshhunt.smugmug.com/gallery/2685411_S68aM/1/284352130_9kxuW#284352130_9kxuW

evoryware

the reflection in the glasses looks to be in focus to me.

You can check the focus points in Canon Zoombrowser with the XTi and I'd guess the focus point isn't on the glasses.

Blurmore

looks like a case of focus recompose strikes again.

joshhuntnm

Blurmore wrote:

looks like a case of focus recompose strikes again.

I am pretty sure i had the focus point on the one that is closest to his glasses, which do look in focus, but his teeth don't. And, I am not shooting wide open so one would think there is a little DOF to work with. Hmmm.

Scott_Quier

If your active focus point was indeed on his glasses, then you have one of two problems going against you. It could be that the camera focused on the reflected image as hinted at by evoryware or your camera is not focusing correctly. I'm seeing the hairs on the side of his neck being in focus.

I'm wondering if you've taken the time to perform a focus accuracy check? Check out this site for more information.

joshhuntnm

Scott_Quier wrote:

If your active focus point was indeed on his glasses, then you have one of two problems going against you. It could be that the camera focused on the reflected image as hinted at by evoryware or your camera is not focusing correctly. I'm seeing the hairs on the side of his neck being in focus.

I'm wondering if you've taken the time to perform a focus accuracy check? Check out this site for more information.

I will see if it happens again. My guess is the shiney nature of those sunglasses fooled the focus mechanism.

jeffreaux2

If you used your 85mm....

In my experience with my 85mm F1.8 for head and shoulder shots such as this...at that range....you can easily stop down to F4 or 4.5 and still throw the BG out of focus if it is any distance at all from your subject.

For reference, the shot below was with similar equipment to yours.

CameraCanon EOS DIGITAL REBEL XTiExposure Time0.002s (1/500)Aperturef/3.5ISO100Focal Length85mm (guess: 142mm in 35mm)Photo Dimensions2592 x 3888File Size4.72 MB

joshhuntnm

jeffreaux2 wrote:

If you used your 85mm....

In my experience with my 85mm F1.8 for head and shoulder shots such as this...at that range....you can easily stop down to F4 or 4.5 and still throw the BG out of focus if it is any distance at all from your subject.

For reference, the shot below was with similar equipment to yours.

CameraCanon EOS DIGITAL REBEL XTiExposure Time0.002s (1/500)Aperturef/3.5ISO100Focal Length85mm (guess: 142mm in 35mm)Photo Dimensions2592 x 3888File Size4.72 MB

Great shot. I think I will try that-- closing it down some more. Why did I buy this lense with the 1.8 aperture again?

jeffreaux2

joshhuntnm wrote:

Great shot. I think I will try that-- closing it down some more. Why did I buy this lense with the 1.8 aperture again?

You bought it because....

-Its bigger better brother (85mm F1.2) is just a tad more expensive making it a great bargain
-It is one of Canon's sharpest non-L primes
-It is a terrific focal legth for portraits
-It is a superfast focuser....think high school basketball
-...and if you are in a pinch for light You have that 1.8 aperture.

Most all lenses will function best when stopped down a tad from max aperture.So you should get very good results at apertures that would be the max for some glass.

I thought mine was missing focus when I first got it. I am able to get consistent results now even at F1.8

...and I dont choose focus points other than the center one. I ALWAYS focus then recompose. This probably isn't the best technique at wide open!

....anyway....practice makes perfect.

F2.5

joshhuntnm

I will keep practicing. thanks for your perspective. Very helpful. Great wedding shot too.

jeffreaux2

joshhuntnm wrote:

I will keep practicing. thanks for your perspective. Very helpful. Great wedding shot too.

I meant to say what a huge mistake I made that day.....the day of those bridal portraits.( I got distracted by FEDEX at the door with a batch of prints!!!)

I had recieved the 85mm only the day before. I got to the location, mounted it to the XTi, and shot every single photo with it. Really scared myself, because I should have used my 50mm and Tamron zoom that I was comfortable with, familiar with, and understood the limits of. As it was, I was extremely lucky . What if the lens had some flaw? In the end it's quality and sharpness kept me from magnifying the poor decision with bad photographs. You must make certain when using this one that everything you want sharp is in the same focal plane. This is especially important if you have more than one person in the portrait...and are using wider apertures.

evoryware

You don't have to guess. You can open up the image in Canon's zoombrowser and check which focus point was activated and where it was on him at the time the shutter is pressed.

joshhuntnm

evoryware wrote:

You don't have to guess. You can open up the image in Canon's zoombrowser and check which focus point was activated and where it was on him at the time the shutter is pressed.

wow. i feel like every answer opens up two more questions. I guess that is the software that came with the camera--the one I never installed? I guess I should?

evoryware

I've had the same issue as you with my cameras and when I open em up in Zoombrowser I find out it was user error. The point wasn't where I intended it to be because I moved it slightly as I went to click the shutter. So a good image becomes trash because I put the point on my goddaughters ear or her nose and not her eye (or because she moved and my tracking was off).
That will let you know for sure if you hit the spot or not and you'll know exactly how to correct it in the future.

joshhuntnm

evoryware wrote:

I've had the same issue as you with my cameras and when I open em up in Zoombrowser I find out it was user error. The point wasn't where I intended it to be because I moved it slightly as I went to click the shutter. So a good image becomes trash because I put the point on my goddaughters ear or her nose and not her eye (or because she moved and my tracking was off).
That will let you know for sure if you hit the spot or not and you'll know exactly how to correct it in the future.

That is good information. I will try to dig up those cds.