Are my Eyes Bad?

a-baird-photograph · January 26, 2008

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Should I bag the kits and go to a prime (drooling over the f1.8 85mm)? Forget becoming better and use Av for everything? Is the camera broke or are my eyes?

pathfinder · January 26, 2008

welcome to the Technique forum, a-baird,

A proper functioning DSLR will usually focus more precisely (in good light at least ) than you will usually be able to achieve manually. Especially without a split image rangefinder reticle in your camera viewfinder. Shooting handheld?

You need to post a couple image or links to the original images, along with exif data, for anyone to make any useful comments about your "blurry" images that we cannot see in your initial post.

Are you shooting RAW or jpgs? Unsharpened RAW images can look soft out of the camera unless processed properly. Some of that is easily handled in Adobe RAW converter. Not a failure of the system, but inherent to the creation of a digitized image, whether from a camera or a scanner.

Av mode is fine for sharp images as long as the shutter speed does not get too slow - typically at least 1/focal length in mm to prevent camera shake being recorded. A tripod is the best "optical device" for enhancing the sharpness of your existing lenses.

Kits lenses are not the equal of L glass, but if used properly can usually create excellent images. Not at their widest aperture, but typically 2 stops smaller than their maximum. A fast shutter speed or a good tripod mount is needed also. I have shot numerous very crisp images with Tamron lenses and Canon non-pro lenses. A lens can be bad of course, but that is usually not the problem. Most lenses can create good images with careful understanding of their native abilities and limitations.

A common reason for unsharp images is technique, or inexperience. If my images are unsharp, even with L glass, it is almost always camera movement on MY part. In low light, focusing becomes more challenging, of course.

If your shots were done tripod mounted, carefully focused, with a remote release and mirror lock up, then we will have different things to discuss.

ChatKat · January 26, 2008

Technique
I handhold my camera much of the time and find that in the excitement of shooting, I tend to forget the rule of 1/focal length for shutter speed. That means if I am shooting with a 50mm focal length, then my shutter speed needs to be at least 1/50th.... 100mm then 1/100th etc. otherwise you get camera shake.

Scott_Quier · January 26, 2008

Something else to consider that I just ran across with two of my bodies - they were both front-focusing. That is to say, the camera was thinking it was focusing on the intended subject, but the image shows that critical focus was achieved at some distance between the camera and that subject.

Check out this page for an idea on how one can test for this. In place of a ruled paper, I simply used a ruler. A tape measure works just as well.

As for my cameras (a 20D and a 30D), I ended up shipping them off to the NJ Canon Factory Service center. You don't even want to know how much I'm paying to set things right. They say they should be out the door back to me by then end of next week.

pathfinder · January 26, 2008

The 20Ds AF system strongly prefers to focus on the closest high contrast area in the image frame. It does not do well when focusing on softer facial features such as eyes, when there are sharply delineated lines of contrast in front of, or behind them. It WILL focus properly if you carefully use one AF point and ride herd on the focusing, but if you are not careful, it will refocus fore or aft. My wife and I still use our 20Ds frequently. The 1 series and the 40D are better at remaining in the proper focusing plane in my experience.

Both of your cameras would not focus reliably, Scott?

cmason · January 26, 2008

A few things to check first: 1) make sure you have one, single focus pt selected, preferably the center one. The camera can be set to allow it to choose the focus pt, where you have all pts selected...this can create some odd results. 2) make sure you have the autofocus in 'one shot' mode, since AI Servo can also choose focus pts you didnt intend.

A good check is to use the included Zoombrowser from Canon, which has a little utility that will show you where the camera was focused in each photo, so you can then look to see if the photo is actually in focus where the camera was focusing.

Scott_Quier · January 26, 2008

pathfinder wrote:

The 20Ds AF system strongly prefers to focus on the closest high contrast area in the image frame. It does not do well when focusing on softer facial features such as eyes, when there are sharply delineated lines of contrast in front of, or behind them. It WILL focus properly if you carefully use one AF point and ride herd on the focusing, but if you are not careful, it will refocus fore or aft. My wife and I still use our 20Ds frequently. The 1 series and the 40D are better at remaining in the proper focusing plane in my experience.

Both of your cameras would not focus reliably, Scott?

Both cameras focus reliably and consistently - just wrong. It was very repeatable using a number of different targets in controlled environments. And, like you, I am abundantly aware of the 20D/30D focusing foibles.

When I started suspecting a problem from looking at photos of different subjects (close scenery, people, cars, etc), I set up the test (using technique discussed in the link I supplied but found else where). Using center focus point, in very good light, and using multiple lenses (EF-S 17-55 f/2.8, EF 24-105 f/4L, EF 70-200 f/2.8L) and at multiple apertures - I discovered that both cameras were close focusing a bit. The 20 more so than the 30. I got the estimates on the fixes back from Canon yesterday and the price to fix the 20 was 50% more than the price for the 30.

Anyway, when I get them back I'll run them through the mill. At that point I will KNOW that Canon thinks they are good. So if I continue to have problems, that we have a pretty good idea wherein lies the fault.

pathfinder · January 26, 2008

Scott, will you share with us, what Canon is charging for this service?

Seems like proper focusing should be a given with a new camera ( I know the 20D and the 30 D are no longer new) , but this problem has been there since the beginning is what I think I hear you saying.

Scott_Quier · January 26, 2008

pathfinder wrote:

Scott, will you share with us, what Canon is charging for this service?

Seems like proper focusing should be a given with a new camera ( I know the 20D and the 30 D are no longer new) , but this problem has been there since the beginning is what I think I hear you saying.

I do not know that the problem has been there since the beginning as I have been, for some time, ignorant of the possibility of the problem. I nearly certain that the problem has not been there since the beginning - I think I would have noticed this as I did some testing when I got the cameras. I got a used lens recently and that's when I started to suspect an issue.

They are long out of warranty as I've had the 20D since 2005 and the 30D since Oct 2006. The charge for the 20D (which happens to have the worst problem) is $305 and the 30D is $195. Steep, but less then it would cost me to replace the cameras and, aside from the focusing issue, these are excellent cameras. Oh, and the price includes shipping

LiquidAir · January 26, 2008

a-baird-photograph wrote:

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Should I bag the kits and go to a prime (drooling over the f1.8 85mm)? Forget becoming better and use Av for everything? Is the camera broke or are my eyes?

If I read this right, you are having trouble with manual focus with the XTi and the kit lens. Truth be told, the viewfinder in the XTi is not great to begin with and the kit lens maximum apeture is relatively small. The net result is that the image you are looking at through the viewfinder is both dark and small which makes it tough to judge focus.

If you are dead set on using manual focus either a camera upgrade and a lens upgrade (or both) will help. The 85/1.8 will give you 2 stops more light to the viewfinder which will help. A 40D will upgrade the viewfinder from a pentamirror to a pentaprisim, also improving your view.

Jane B. · January 26, 2008

a-baird-photograph wrote:

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus (bold & italic added by J.B.) for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Snip

In rereading the OP's description of the problem it appears that the Auto-focus is fine. But. . . that the problem is with Manual-focus. So, I can't help but wonder if it is simply a matter of the diopter adjustment is not set right for the individual's eyes. Even my old D60 has a diopter adjustment knob to set for my eyes.
Jane B.

evoryware · January 26, 2008

Jane B. wrote:

a-baird-photograph wrote:

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus (bold & italic added by J.B.) for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Snip

In rereading the OP's description of the problem it appears that the Auto-focus is fine. But. . . that the problem is with Manual-focus. So, I can't help but wonder if it is simply a matter of the diopter adjustment is not set right for the individual's eyes. Even my old D60 has a diopter adjustment knob to set for my eyes.
Jane B.

That's what I was going to say. Do the focus points look sharp through the viewfinder? Adjust the diopter for the focusing points you see through the viewfinder and make sure they are sharp, then try again. When I first wanted to learn manual focus, I would focus manually on a tripod, then switch to auto and see if it changed. Many times it didn't. It would just beep.

Scott_Quier · January 26, 2008

Jane B. wrote:

a-baird-photograph wrote:

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus (bold & italic added by J.B.) for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Snip

In rereading the OP's description of the problem it appears that the Auto-focus is fine. But. . . that the problem is with Manual-focus. So, I can't help but wonder if it is simply a matter of the diopter adjustment is not set right for the individual's eyes. Even my old D60 has a diopter adjustment knob to set for my eyes.
Jane B.

Nope. If the diopter adjustment is off, there is zero chance the view in the viewfinder will appear to be sharp. But, I do have to admit that you zeroed in on something that the rest of us missed - or at least me! Good catch.

jfriend · January 26, 2008

a-baird-photograph wrote:

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Should I bag the kits and go to a prime (drooling over the f1.8 85mm)? Forget becoming better and use Av for everything? Is the camera broke or are my eyes?

Since we're discussing "manual focus" here:

Most of today's cameras are not optimized very well for manual focus. It can work pretty well when the depth of field is very narrow, but with no focusing screen optimized for manual focus and not a particularly large or bright viewfinder, it can be a bit difficult to do manual focus.

A wide aperture lens (prime or not) will make manual focusing a little easier because the wider the aperture, the narrower the depth of field when focusing and the more light you get to work with (today's cameras/lenses all do focusing at max aperture).

May I ask why you are trying to use manual focus? The only times I use manual focus are for macro work and when I'm trying to manually set hyperfocal. At all other times, I find the auto-focus is more accurate than I can manually focus as long as I make sure the right focus target is on the right part of my subject when I trigger auto-focus.

Jane B. · January 26, 2008

Scott_Quier wrote:

Jane B. wrote:

a-baird-photograph wrote:

I use the XTi and the silly kit lenses (for now). I've really tried to focus lately (no pun intended) on using manual focus (bold & italic added by J.B.) for the images I capture. Through the view finder, subjects look perfectly sharp. In post, they are blurry as all blurry. I've historically used Av for my images. When I shoot this way in the view finder they look sharp and post they are sharp.

Snip
Nope. If the diopter adjustment is off, there is zero chance the view in the viewfinder will appear to be sharp. But, I do have to admit that you zeroed in on something that the rest of us missed - or at least me! Good catch.

It still seems to me that if he/she manually focuses the lens until the viewfinder looks sharp but the diopter is off then the shot will be blurry when viewed on the computer later.
Jane

LiquidAir · January 26, 2008

Jane B. wrote:

Scott_Quier wrote:

Jane B. wrote:

It still seems to me that if he/she manually focuses the lens until the viewfinder looks sharp but the diopter is off then the shot will be blurry when viewed on the computer later.
Jane

Scott is right. An SLR viewfinder has two stanges. The image from the main objective is brought into focus on a ground glass focusing screen which is what you see reflected in the mirror when the lens is off. There secondary lens system which you look through to see the ground glass. The diopter adjustment controls the focus of your view of the focusing screen. If it is not set right everything will be out of focus all the time including your view of the focus points and the viewfinder exposure display.

jfriend · January 26, 2008

LiquidAir wrote:

Jane B. wrote:

Scott_Quier wrote:

Scott is right. An SLR viewfinder has two stanges. The image from the main objective is brought into focus on a ground glass focusing screen which is what you see reflected in the mirror when the lens is off. There secondary lens system which you look through to see the ground glass. The diopter adjustment controls the focus of your view of the focusing screen. If it is not set right everything will be out of focus all the time including your view of the focus points and the viewfinder exposure display.

But, I think that even if the diopter adjustment is off, the point of sharpest focus will still be accurate. It's just that that point of sharpest focus won't appear as sharp as it could when viewed through the diopter. It doesn't cause the point of sharpest focus to shift.

As an analogy. If you need glasses in order to see the movie screen in sharp focus and you take your glasses off so the movie is now blurry. Then, you have someone at the project mess with the focus of the projector and ask you to tell them when the image is it's sharpest. Even though it's a bit blurry for you, you will still see the best image possible at the point of best focus. And that point will be the same with or without your glasses. Of course, it is probably easier for you to identify the point of sharpest focus with your glasses on, but taking them off doesn't introduce any focus bias, just an extra challenge for getting it right.

LiquidAir · January 27, 2008

jfriend wrote:

But, I think that even if the diopter adjustment is off, the point of sharpest focus will still be accurate. It's just that that point of sharpest focus won't appear as sharp as it could when viewed through the diopter. It doesn't cause the point of sharpest focus to shift.

Exactly.

There are really two possible ways that manual focus can go wrong. The more common of them is simply that the view through the viewfinder doesn't let you judge focus accurately. A mis-set diopter would definitely have that effect. However, I think even in the best of cirumstances it is hard to accurately judge focus on a XTi with the kit lens. If, however, you find an actual focus shift, the most likley cause would be a misaligned mirror or focus screen. On an XTi, that would likely require sending the camera in for service.

Manual focus cameras usually had a prisim or split in the focus screen to help you judge focus. However those features interfere with autofocus systems so modern cameras don't have them. If you intend to focus manually most of the time, it is worth looking into a third party replacement focus screen.

cmason · January 27, 2008

Even when you manual focus, the autofocus functions are still operating. The green focus confirmation dot will light up when the object is in focus, helping you to confirm focus, in a somewhat, kinda, similar fashion that a split screen does.

If the focus confirmation is not coming on, you may need to examine the diopter or even have the camera checked by Canon. First, why not run a focus test yourself, to see if you can reliably repeat the issue:

Download and print the PDF file found on this page:

http://focustestchart.com/chart.html

a-baird-photograph · January 27, 2008

Thanks all for the wonderful discussion. I've learned a bunch, need to try working with it tomorrow. Crazy weekend.

A few points to highlight. I mostly use a tripod and cable release. I didn't know about the 1/focal length. I'll go through my images and check to see if that's a root cause.

I've been working on manual focus to get that "perfect" focus on the eyes in portraits. I almost exclusively use the center weight metering and center focus box. Rather than position the camera to focus on the eyes, the reposition to compose, manual focus was to make it easier.

I've printed the test, and I'll give it a try. I'll also post the results. Thanks for you all of your wisdom. I'm sure most of you have forgotten more than I'll ever know. Cheers.

Alex

Scott_Quier · February 2, 2008

pathfinder wrote:

The 20Ds AF system strongly prefers to focus on the closest high contrast area in the image frame. It does not do well when focusing on softer facial features such as eyes, when there are sharply delineated lines of contrast in front of, or behind them. It WILL focus properly if you carefully use one AF point and ride herd on the focusing, but if you are not careful, it will refocus fore or aft. My wife and I still use our 20Ds frequently. The 1 series and the 40D are better at remaining in the proper focusing plane in my experience.

Both of your cameras would not focus reliably, Scott?

A follow-up/update on the service I got from the NJ Factory Service Center.

First, let me say that they did what they said they would do - they got it out the door on the 29th and I got them a couple of days later

They both came back tack-sharp. I tested both cameras with EF 85 f/1.8, EF-S 17-55, and EF 24-105 f/4L and focal distances varying from a couple of feet to over 30 feet. The zooms were also tested at various focal lengths.

20D:
Electircal adjustments were carried out, other electrical adjustments, inspection, and cleaning, mechanical adjustments and parts replacements (though there was no parts charge on the invoice

)

30D:
Updated firmware, adjusted exposure & focus, cleaned CMOS to factory specs (haven't tested to see just how clean/dirty that might be).

Am I happy with the service? Yep - they did what I wanted (and then some) and they did it quickly. I got the cameras back 10 days after I sent them off and 4 days after they started work on them - remember, in that time span there was shipping two-ways, they inspected and performed diagnostics, prepared and estimate, e-mailed the estimate, waited for my response, performed the work, packed it all back up and shipped them back to me.

Are my Eyes Bad?

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