Hi everybody,
I have some problem with my Canon EF 24-70 L lens focusing technique on my EOS 20D and i decided to bring this issue up in here to see if i can find any solution to it (Thanks to PAul suggesting me to do so). there was a review in this web site stating that this lens is tack sharp. Actually i have this lens as my primary lens and to tell you the truth i can not take picture as sharp as what i used to take with my old Olympus C5050z!! i mean i have to use unsharp mask in PS CS2 to make the shots sharp enough. I thought that this lens is a bit soft but when i read this review by conrad i changed my mind and now i think that it is definitely my weakness in getting the right focus. Here is my procedure to focus:
in manual mode i focus the subject and when i think it is focused ok, i half press the shutter and the middle focus point in the camera blinks red which confirms the proper focus, but when taking the shot and looking at it in preview mode, it is not focused very good i mean it is not sharp enough.
In auto focus mode, i simply point the camera on a high contrast area in the subject and focus, but again unsuccessful.
i would like to attach a sample from each method i.e manual focused and auto focused together with a sample taken with Olympus C5050z to describe the problem better, but i don't know how to do this here and it seems that simply copying and pasting these samples here does not work. : ) i will be appreciated if you kindly let me know how i can attach a sample picture to my posts and also enlighten me with whatever technique (s) that might help me with this focusing problem.

When you created this post, if you went further down the window you would have seen an Upload image button, if you clicked on that, it would then take you to a popup window and you upload the image, once the image has uploaded you then close the box and the image upload link will then be posted when you post the topic thread. You then get to see the image in your post.

If you now click on Quick Reply and then select the Go Advanced button you will be also able to upload an image in exactly the same way as you would have been able to on first creating the original post.

It may not be you, some 20D's have AF issues out of the box. Does it focus properly in MF mode? If so, send it to Canon for warranty repair.

JS

Thanks for posting in the forum, Soheil.

Do you have only the one lens?
I found that when I thought I had problems, it was very useful to be able to test with more than one lens to make sure that it was not a lens problem, instead of a camera problem.


It is nornal with a DSLR to have to use USM to sharpen the image if you have the camera parameters set to standard, with no extra sharpening, no colour ehnahncement.
But usually only one pass of sharpening is all that's needed.

You can not use USM to correct an image that is out of focus, it will still be out of focus, but what I find is that any noise in the image is also enhanced by the sahrpening and so if the focus is not good to begin with then it can look noisier as a result.


As JS said, it might be the camera, but I'd like to wait until we've seen the images to be sure.


I've attached a few images taken with my 24-70, these are 100% cut out 640x480 from the original image, with no sharpening.
Yes, including one that is out of focus. I know it's my fault it is out of focus because in the full size picture the focus on her t-shirt is pin sharp, and I can see the weave of the cloth.
My mistake there !

You can see that with direct flash the lens is too sharp to take flattering photos of these faces and it shows every pore and spot. You should be able to get photograps this sharp with your 20D.

I would suggest that you try out another lens with the 20D if you haven't already. If you don't have another lens, you could take the camera to a camera or electronic store and ask to try out one of their lenses on the camera. This way, you could tell if it is the camera. It's possible the lens or the camera needs to be calibrated - or calibrated together. Did you get them together?

You could also call the dealer and ask them to exchange both the camera and the lens if you're still in the return policy period.

As has been previously said, it seems to be a common phenomenom today that a camera and/or lens or both together need calibrated.

Liz

Hi Soheil,

Welcome to the world of DSLR photography. You'll find that it there are many differences between using your 20D and using a point and shoot.

By design, DSLRs are designed to give you more creative control. This means that you'll have to do some post-processing on your computer before you get the final print, such as color correction and sharpening. Point-and-shoots are different because they do a lot of this in camera so you only have to crop and print.

Before you take your camera back, consider a few other options that may be causing this problem. Do you use all the focus points, or do you select the focus point depending on the shot? Do you use Custom Function 4 to have the * button handle the focusing? Also consider that you may be getting some motion blur due to the conditions you're shooting in.

There are a number of reasons that could cause you to have photos that appear out of focus. Hardware isn't the only cause of the problem...it could very well be your technique or some software setting.

Thanks everybody for your kind replies. Peter thanks for your kind instructions on how to upload images. To answer some of the questions i would like to inform you that this is my only lens and i bought it when i bought my camear. Paul, I never use built in flash for my portraits, and that is perhaps one reason for my pictures to be a bit soft. For your Info Most of my pics are like your top left sample. As i know how to attach files to my posts; here are three shots of a texture one in manual focus, one with AF and the last with my OLY C5050z.
I've uploaded the images but for me they appear as attachments hope you can use them and post your ideas about them.
Once again i would like to thank all of you taking time and review my images.


Regards.
Soheil

From your images, you are shooting close as the 24-70 is capable of doing so. Perhaps your AF mode is set to One-Shot AF (I suppose the 20D has it - I have the 10D)? After you verify the focus by pressing the shutter half-way, if you move your body/camera a hair, that shallow depth of field is going to be out of range.

Below is an unprocessed test shot I made with the same lens at f/4 at 70mm. Can you try a 3-D scenario like this to see if there is any part of the shot that is in focus? If so, and it is not where it should be, then you probably have a hardware problem.

Nice example, you can see the AF locked on the nearest part of the nut, and the depth of field is clear in the cracked paint.

Have you tried turning the dioptic adjuster? It may be that your eyes are not quite 20/20 and you don't realize it (it's how I learned I needed to shoot with contacts!).

Try using AF and whe the camera indicates it's focused, turning the dioptic adjuster until the image is razor sharp in your viewfinder.


Hope it helps.

Jody

Nice example, you can see the AF locked on the nearest part of the nut, and the depth of field is clear in the cracked paint.


That reminds me - I've got to paint the house this year!