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Old Dec 8, 2003, 11:55 PM   #1
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Default 10D and Focus problems

I recently bought a new 10D and I am using an older Canon lens, Ultrasonic 28-80 lens. I have been very disappointed with the sharpness of my subjects. I have read the discussion groups on the front/back focusing issue and have tested the camera using the chart at photo.net (it passed), however a vast majority of my pictures (especially people/faces) are out of focus (despite higher fstops and speeds). I have been using the center box as the focus point.

I have seen other examples posted from this camera, and there is no doubt that others are acheiving crisp, sharp photos. This leads me to think that it may be the lens. Has anyone had focusing problems with the older Ultrasonic lenses? Are the images from the 10D soft in general? Any advice on further testing or correcting this issue? Any affordable (<$400) lens recommendations?

I must say that for the price of this camera, so far the results are disappointing. The main reason I finally purchased a digital SLR was to avoid the focusing issues when photographing my 4-yr old son with the Nikon 4300 (often out of focus).
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Old Dec 9, 2003, 8:03 AM   #2
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Do you zoom in to focus and zoom out to recompose?... This usually change the focus front/back, and most affordable AF zoom have this problem

Repeat the chart test, first take a shot at 80mm and without re-focus change the lens to 28mm and take another shot. Next focus at 28mm take a shot then zoom in to 80 without re-focus and take another shot: See if the focusing postion changes when you zoom in or out and learn to 'untrain' your film camera reflex. :P
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Old Dec 9, 2003, 8:12 AM   #3
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Could you post an example somewhere so we could see?

Another thought beyond NHL's is that maybe you aren't used to the slightly soft pictures that the 10D produces. The designers of the 10D expect you do add sharpness in your computer (with photoshop or something similar.) This is a good thing because it allows for flexability in pictures. If you want a sharp picture, you can add it. If you want something slightly soft (like a portrate) then you can add less. The problem is that its easy to add sharpness, but very hard to remove it. If it's output was quite sharp out-of-camera, then it would actually be bad for some photographers.

If you are used to a consumer grade camera (like the CP4300) they usually have higher sharpening settings by default because a different group of people (shoot different things) use the camera and have different needs. The average CP4300 shooter just wants sharp pictures with little hassle. The 10D user (based on canon's marketing research) want the flexability of less incamera sharpening.

Eric

ps. As a side note, the D Rebel's target market is different than the 10D's and they want more sharpening... so its in-camera sharpening defaults to a higher value (but they have the same scale) than the 10D.
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Old Dec 9, 2003, 1:37 PM   #4
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Isn't there an adjustment setting on the 10D to increase the degree of sharpness?
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Old Dec 9, 2003, 1:56 PM   #5
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Quote:
Isn't there an adjustment setting on the 10D to increase the degree of sharpness?
Yes

It's on the menu under Parameters, by default it's set on Standard. Just pick a different set Set1 for example in the SetUp and in it you can change the sharpness, as well as contrast, saturation, and color tone...

I wouldn't crank it up too much though since you can have a much better control with USM in Photoshop
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Old Dec 9, 2003, 11:29 PM   #6
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Post a sample picture, you'll be more likely to get a correct reply from someone here.

NHL, all my Canon lenses recommend in the manual to not zoom after focussing (17-40L, 50/1.8, 28-135 IS and 70-200L IS). Not a problem for me, I never do this anyway. Just found it curious that you keep bringing it up and even the Canon L lenses cannot handle it.

Barthold
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Old Dec 10, 2003, 7:42 AM   #7
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Barthold

Coming from the old school (ie non AF SLR), all my older zooms from various manufacturers including Canon's FD do not need re-focus when zooming. In the old day people usually zoom in to manually focus on the magnified details and back out to recompose. True-zooms do not do this since it would be a pain to use on a manual focus camera. Vivitar was the only manufacturer at the time to introduce a not so popular varifocal, but its design made the lens extremely compact for a high ratio zoom.

With the advance in AF true-zooms are no longer required (or push-pull mechanisms) and why AF zoom are more compact and lighter, but failing to use AI focus while zooming will usually end up in front/back focus. Call it by habit if you want, but USM/HSM full time manual overide is critical for me... Am I the only one to use manual focus here? It doesn't hurt to double check the camera!

http://www.stevesforums.com/phpBB2/v...ight=varifocal

BTW the Sigma 70-200 f/2.8 EX HSM do not change focus while zooming...
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Old Dec 10, 2003, 12:44 PM   #8
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Well, to answer NHL's question I do manual focus some times, but not often.

I'm hooked on full-time manual override, though. I wouldn't want to buy a lens without out.

Eric
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Old Dec 10, 2003, 3:08 PM   #9
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Hi NHL, Eric,


This is the usual way of using a AF lens:

1. You zoom in, press the shutter button down half way, camera focusses.

2. Next you zoom out, press the shutter button (you have to to take a picture :-)), camera re-focusses. No big deal right?

It only is an issue if you don't use the AF on a AF lens, as you explained. That seems like an expensive way of using an AF lens though.

Actually, strictly speaking step 1 might not even be necessary.

It seems that in order to get accurate manual focus you will need to zoom in first, focus, then zoom out to re-compose. If you would focus zoomed out you probably don't get it focussed accurately enough. Right?

The assumption Canon, and others, make is that step 2 will result in accurate focus at the zoomed out view. In other words, Canon believes their AF system is better than you can do manually. Probably not always true, but I can see the logic.

Barthold
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Old Dec 10, 2003, 7:35 PM   #10
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If I did exactly what you described in 1 & 2, I would get out of focus pictures every time. What you didn't include is this:

1.5) take finger off shutter button.

If you 1/2 press the shutter (it focuses) then you change the zoom and press the shutter the rest of the way it will not refocus. It will just take the picture.

My 10D will not always put all of my subject in focus. So I adjust the focus after it has done it's best so that the DOF covers what I want (as opposed to what it thinks is in focus.)

I do agree, though, that Canon things its AF is good enough that you won't use manual focus much. And it's true, I don't. But I also don't think its AF is very good. It isn't bad... I'd even say it's "good enough" but "very good" is too strong to me.

To me, the real reason why manual is hard is because the view finder is not designed to do manual focus very well. Read this article to learn some very interesting details about view finders:

http://www.luminous-landscape.com/co...03-03-16.shtml

Here is an example of why full time MF is a good thing. I used it for this picture:

http://www.stevesforums.com/phpBB2/v...ic.php?t=17837

I didn't have to (I could have just done MF instead of giving the AF a go at it) but that's not how I did it. I let AF try, and when it focused on the vines in front, I just fixed the focus myself. Personally, I expected it to be confused by the snow, but it wasn't. I guess the flakes were too small to bother it.

Eric

ps. I always skip step #1. Since I'll need to refocus every time I zoom, I see no benefit from zooming in, letting AF focus, zooming to what I want and then letting AF refocus.
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