View Full Version : Point of Focus

09-09-2011, 04:09 PM
OK, I am just starting from the beginning again. I am not worried about anything but the point of focus. When I upload my images to my computer, I notice my point of focus is off just a little. Here are a couple simple shots just around the house. I was practicing focusing on the texture in the subjects. They look in focus in the viewfinder, but just off when I see it enlarged. I do wear glasses. Are these affecting my focus?



09-09-2011, 04:29 PM
In AF, your glasses or the diopter adjustment will only effect what you see, not what the camera captures. To help find the problem source you really need to eliminate the variables which in most cases is the photographer. Use a tripod and a cable release and take a photo in good light. Make sure there is a very good line of definition that you are focusing on. Put the camera at the lowest normal shutter speed and try at a few different aperture settings. This little exercise usually highlights the problem as being the shooter. If you still have any misgivings try going though this link below or something similar. Don't worry about the reference to a specific camera.

Nikon D70 Focus Chart (http://focustestchart.com/chart.html)

09-09-2011, 05:58 PM
The image of the vases is taken from a tripod (no cable release) and in manual focus ( both are manual focus). I don't know the settings (I'm at work now, don't have my camera). The image of the balls was handheld.

(btw, the image of the vases is growing on me).

09-10-2011, 04:24 PM
OK, a couple more today from my favorite test subjects

To me, the first one below is in much better in focus, but a little over exposed



09-10-2011, 07:30 PM
Concerns with my camera. If you look at the image of the vases from yesterday, just below the blue dot to the right is a red spot. (its right in the seam of the skirt of the coach) It was on every image I took yesterday. It is not on the images I took today.

Should I have any concerns?

(btw, the blue dot must have been a piece of dust floating by because there was nothing there and the blue image was not on any other image).

09-10-2011, 09:21 PM
I can't see the dot......
re: focus- things can look nice and sharp on the small led screen but turn out to be too soft once you look at them large. keep playing and you will find the range of your lens and how to control the focus point. you can try playing with manual focus for a while to see if that helps you

09-11-2011, 09:24 AM
The following test may help -

IF you have live view and you are on a tripod, take a shot normally.
Then take another using live view and ENLARGING the view until what you focus on is tack sharp in the viewfinder relative to the objects around it.
Then compare the two shots. If the live view shot is consistently sharper, there's probably nothing wrong with the camera.

There's also some basic shutterspeed knowledge you are forgetting. 1/60 is around the minimum for handholding the camera on any subject. The balls shot was shot at 1/2 second.... it's blurry because of that.
I did a podcast on sharpness that covers these and similar basics. I recommend u take a listen or do similar reading. 70 – Getting sharper images – common problems | Photography podcast blog and forum - Photography.ca (http://www.photography.ca/blog/2009/08/05/getting-sharper-images-common-problems/)

To get better feedback when you talk about a "shot being in focus", please tell us exactly where in the image you focused. As far as I am concerned the vases are not in sharp focus and the focus was missed.
Hope that helps - Marko

09-11-2011, 05:03 PM
Thanks for the advice Marko, I did what you suggested, here are the results. The focus point is the upper gold ring on the right vase. I've been trying to get little black texture of the ring in focus this whole time

1st shot - tripod, AF, Live view 10X zoom


2nd shot - tripod, MF, Live view 10X zoom


3rd shot - tripod, MF, viewfinder


4th shot (daddy, take my picture) tripod, AF, Live view, 10x focus on her eyes


09-11-2011, 05:31 PM
Not the results I was expecting. Honestly through, i can't be sure that your vision is not a variable here....and your point of focus should be more precise than a curved upper gold ring (that's not a 'point') for this test. We are looking for MAJOR precision here to rule out variables.

NOTE - If you have a vibration reduction - image stabilizing lens - and you are on a tripod - shut it OFF.

Every single shot, to my eye shows sharper focus behind the subject.
You are still committing basic errors though that may be skewing these results. The shot of your cutie daughter was shot at 1/3. Too slow. Up it to 1/60 minimum - tripod or no tripod because unlike the vases, your daughter has a Natural movement

I would try a more basic test. Newspaper tacked to the wall evenly lit with bright light so you have a lower iso. Camera on tripod directly in front of newspaper. Focus on the print close so we can read it easily - make it fill the frame... with live view.
No slow shutterspeeds, please, I want to see the faster ones. 1/60 1/125 1/250

Andrew's link is a good one and you should take a read.

Hope that helps - Marko

09-11-2011, 06:05 PM
Use the DoF button, Luke......

09-11-2011, 07:43 PM
People with bi-focals (that's right, I mean you old people). Do you look through you bi-focal lens or just your normal lens when shooting? I do not wear bi-focals, but probably could use them. I sit at a computer station for 12 hours monitoring 5 screens at a chemical plant. I was told when I took this job on the board, I would need bi-focals within a year. Plus this iPhone don't help either

09-11-2011, 10:22 PM
Bi-focals with the camera's diopter adjustment used