5D Focus Issues

<p>Before I take my Canon 5D and lenses in for a check up, I thought I'd post this and see if I can get some "brain share" and maybe solve the problem myself. If the local repair shop can't do it I'll have to ship it to Canon in California.</p>

<p>My lenses are the 100 f2.8 macro and a 50mm f1.4.</p>

<p>I shoot mainly model talent in my studio with Speedotron gear, typically at 1/125th, f5.6. In my studio, I want the background (seamless paper) out of focus. Seems like I shoot a LOT of what I do at these settings.</p>

<p>I'm also fond of the back-focus button setting, which I hit between every exposure. I like this feature, and I wait for the confirmation beep before tripping the shutter. (The shutter pressed half-way down does NOT activate the autofocus; the back-focus button does.)</p>

<p>I set only ONE focus point, usually near the top. My camera is held vertically, so the top focus point will (typically) fall on the subjects face.</p>

<p>I leave the overhead studio lights ON, as well. It makes focusing much easier.</p>

<p>Yes, I fire a lot of frames, as quickly as the power pack can recycle and beep. This ain't film, obviously.</p>

<p>But as I review my many images, I'm find a lot of them are soft. I can finesse them into a web image, but this is unacceptable. Some are tack sharp, many are just off enough to be...unacceptable. </p>

<p>What's going on? Is it my sloppy, rapid-fire technique? I get a confirmation beep but is the autofocus NOT keeping up? Or off just slightly?</p>

<p>A lot of these shots are 3/4 or full length, sometimes headshots (or beauty shots.)</p>

<p>Should I have the autofocus checked on this camera? Is it a lens-to-camera alignment issue? A low-light or low-contrast issue?</p>

<p>Some images are tack sharp, some are not. So a confirmation beep does NOT mean the image is tack sharp in focus?</p>

<p>Any comments? Suggestions? I can't imagine going back to manually focusing the lens for every shot. Or should I?</p>

<p>Thanks!</p>

<p>I used a 5D with an Nikon f/1.2 lens, and the depth of field is really very shallow, especially close-in. Perhaps your own body "sway", even at f/5.6, is causing slight movements out of focus. I presume the AF is working at f/1.4 in this case....<br>

Another possibility is that at 1/125 you might be getting the flash <em>and</em> some additional exposure (movement blur) from the overhead lights?</p>

<p>Or perhaps you've eliminated these?</p>

<p> </p>

<p>Thanks - I have considered a slight "shutter shake" since the overheads are ON and my shutter speed is only 1/125th, hand-held. (The sync speed for this camera with studio strobe packs is ONLY 1/125th, not 1/160th like advertised. 1/160th is for speedlights, not strobes.)</p>

<p>I could try going back to my tripod, but it tends to constrain me and becomes a pain. </p>

<p>As for DOF, I considered that, too. I know if I shoot at f8 I start to see more detail in the seamless, which by the way is in perfect condition. A soft, smooth background is just part of my style, I suppose. One light on white is a common look for fashion and beauty, and the background renders a light gray.</p>

<p>The subject is about 8-10 feet away from my camera, so at f5.6 I should have enough DOF. (Beauty shots are another thing, of course. At f5.6 your DOF is paper thin.)</p>

<p>>Perhaps your own body "sway", even at f/5.6, is causing slight movements out of focus.</p>

<p>Possibly, but I'm really aware of this sharpness problem these days and I try to hold it steady! Maybe a tripod would eliminate this variable.</p>

<p>Stop down to f8 and shoot some more? I know I'll start to seem more "character" in the seamless background, but it could be a way to eliminate a variable.</p>

<p>What else are we overlooking?</p>

<p>I mean, a 100mm lens at f5.6, focused 8-10' away isn't producing consistently sharp images, even with a focus confirmation beep. Shutter shake or DOF?</p>

<p>Thanks again.</p>

 

<p>When I shot a 5D the center point was extremely accurate and rarely missed. However, the outer points were a couple notches down in reliability, and only really dependable in bright light. I used to refresh AF between macro shoots with the EF 50 2.5CM and a single outer point covers such a large area (double the size of the VF point) it would often lock on different points of contrast, throwing my subject out. Spot AF (reduced point size) isn't available on the 5D so I found it best to lock AF, check on the LCD and leave it there until I moved the tripod. Using Speedlite AF assist in low light helped the reliability of the outer points greatly (disable flash/enable AF assist on the Speedlite CF menu).</p>

<p>1. What are the ambient conditions like and what ISO? The non-center focus points are just not as accurate for one thing. In dimmer light, they will not perform as well as the center point and none of the points will perform well in really dim light. If you own a 580EX or some other EX flash, you can set it to give you focus assist without the flash going off. Focus assist is surer.</p>

<p>Or, your ambient may be bright enough (that's why the ISO question) that the flash isn't freezing motion--yours or the model's.</p>

<p>2. I have found Canon focusing to be somewhat erratic--too soon to decide that something is in focus, so if you are working fast, you can end up with more than a small percentage of OOF shots. I find focusing twice (hit the * button twice) helps, but probably not for your type of shooting.</p>

<p>Re-do your basic focusing--make sure your focus point is on a contrasty target and don't focus on edges (to avoid backfocusing). Also, Canons tend to jump to the closest contrasty thing when you are in a hurry and don't confirm focus. For instance, you focus on something slightly in front of a model's face (in a close up), but then the focus jumps to the model's eyelashes because they are contrasty.</p>

<p>3. It is possible your lenses or body are out of alignment, but many people think the same, when in fact, they are fine. Do the ruler test yourself before sending everything in, and rule out the above.</p>

<p><em>>When I shot a 5D the center point was extremely accurate and rarely missed.</em></p>

<p>Well! Good to know! I guess I'll switch it to the center point, and see what if that improves things. At that focus distance, I would have to assume the subject's waste is basically in the same plane as the face (or eyes.) There HAS to be enough DOF for the waste and face to be in focus.</p>

<p>You have to realize, I'm shooting a moving model, hand-held at f5.6, and I have to be quick and precise. Macro shots are another thing, and I'd undoubtedly shoot on a tripod, manual focus.</p>

<p><em>>Using Speedlite AF assist in low light helped...</em></p>

<p>No speedlights, I'm afraid. Just studio strobes with a Canon 5D. </p>

<p>Let's see what else we can come up with.</p>

<p>Anyone?</p>

<p> </p>

<p>Nadine:</p>

<p>I'm shooting at ISO 100, with the studio overheads ON. Not especially bright, but although a lot of people shoot with the lights off (relying on just the modeling lights) I really need that light to focus. </p>

<p>I should, just for kicks, take an ambient light meter reading to see if shutter shake is really a possibility. The shutter speed and strobes are NOT fast enough to stop a model jumping, I've found. </p>

<p>>make sure your focus point is on a contrasty target</p>

<p>Yes, I agree with that. That's why I tend to focus on the face, where there's something obvious for the camera to focus on. But I have to get away from the outside focus points, as two of you have indicated. Hopefully there's enough contrast around the subjects middle or waste to focus on. </p>

<p>>I find focusing twice (hit the * button twice) helps, but probably not for your type of shooting.</p>

<p>But...maybe a necessity. I have to wait for he strobes to recycle anyway, so I might as well hit the focus button twice to fix this problem.</p>

<p>>and don't focus on edges</p>

<p>You know, I actually LOOK for edges to focus on, like red lips on pale skin, or pupils. That's where I assume the contrast is, making it easier for the camera to focus.</p>

<p>Maybe THAT'S the problem? </p>

<p>Let's keep the conversation going, and thanks, everyone.</p>

 

<p>Shooting w/ center point and focus/recompose worked well for me w/ the 5D. I found the outer points were simply unreliable, and varied widely w/ the lens. The basic mechanics easily explain your problem.</p>

<p>For example, w/ the 50/1.4 (which is particularly bad WO), the camera obtains 'optimal' focus at a side point <em>while the lens is WO </em>- with a very narrow DOF (and off to the blurry side). It then stops down the lens and opens the shutter. Since you are shooting @ f5.6, even though the DOF is ~ a couple of feet, you are (obviously) falling out of the DOF - when the lens is stopped down. While focus shift may account for this, I expect the source of the problem is the camera's AF trying to get 'decent' focus out a lens whose WO sharpness can be best described as 'lumpy', and having found it at that point, proceeds. <br>

And while focus shift <em>does</em> occur w/ this lens, it's actually not bad, and doesn't occur to the extent necessary to throw your stuff that far off.</p>

<p>W/ the 5D and a 50/1.4 I had no problem (using focus recompose technique) getting and keeping focus using the center point. The geometry does affect the shooting circumstances enough to make a problem, but not @ f4-5.6, I used to shoot w/ the pair @ f2 all the time, and it required the careful positioning.</p>

<p> </p>

<p>Thank you, Marcus.</p>

<p>Looks like I better switch my focus point to the CENTER, and check my autofocus more carefully.</p>

<p>Thanks, everyone.</p>

<p> </p>

<p>By edges, I mean an edge where what's behind the edge is far away or way closer, not within the DOF anyway. For instance, if you put the focus point on the edge of a person's sleeve, with what's behind the sleeve being some contrasty shrubbery 10 feet away, the chances are greater the camera is going to go for the shrubbery.</p>

<p>With close ups, red lips on pale skin or pupils are great to focus on, since the target is large enough and there isn't anything far away behind the edge.</p>

<p>Focusing on a person's waist in, say, a 1/2 or 3/4 length shot isn't good if you have narrow DOF. I've done this and the face falls out of the DOF while you get a real good focused tie, for instance.</p>

<p>At ISO 100, I doubt the problem is not enough margin on shutter drag. However, it could be the outer focus points flaking out on you in dimmer light.</p>

<p>I have a 5D and do a fair amount of portrait work. I agree with what everyone else is saying, especially using the center focus point. I always focus with it, and then reframe, and the number of keepers I get from a session is fairly high. Even when I am shooting between f1.8 and f 2.8 with my 50 (1.8) MK I, I get accurate focus. I always shoot for the eyes, and if the model's head is turned I shoot for the closest eye because the depth of field can be shallow enough that ZI want the closest eye in focus for sure. Good luck.</p>

<p>Thanks, everyone. </p>

<p>Center focus point, it is. Hit the back-focus button TWICE, and confirm a correct focus. </p>

<p>Tom Hanser</p>

<blockquote>

<p>I'm also fond of the <strong><em>back-focus button setting, which I hit between every exposure.</em></strong> Yes<strong><em>, I fire a lot of frames, as quickly as the power pack can recycle and beep</em></strong>. This ain't film, obviously. But as I review my many images, I'm find a lot of them are soft. I can finesse them into a web image, but this is unacceptable. <strong><em>Some are tack sharp, many are just off enough to be...unacceptable. </em></strong></p>

</blockquote>

<p>One variable which I didn’t notice was covered was the AF MODE.</p>

<p>Are you using “ONE SHOT”?</p>

<p>WW</p>

<p>IF the subject is not moving you might try manually focusing once and see if the rest of the images remain in focus. </p>

<p>My camera is set to ONE SHOT, but that's a good point to bring up.</p>

<p>Thanks, everyone.</p>

<p> </p>

<p>Glenn:</p>

<p>I've tried that, but since the model/talent changes position so often and I'm shooting mostly at f5.6, I REALLY have to focus every time. I've been getting killed by soft images.</p>

<p>Thanks!</p>

<p>Hello, Everyone:<br>

<br />Although the time with my Canon 5D is limited due to pending upgrade, I'm still having problems with autofocus.</p>

<p>I was shooting laptops in my studio for a client of mine last week, and although I had a confirmation beep and the red rectangle icon the image was NOT sharp. I can clearly see that it's not sharp, and I was shooting slowly on a tripod, f32 at 1/125th second. </p>

<p>What's up with this camera? <br>

<br />I was focused on the edge of the laptop, closed, where there is enough contrast to focus on. Well, in my opinion there was enough contrast!</p>

<p>Simply put, if I get a confirmation beep and the scene is out of focus, it must be the autofocus mechanism in the camera?<br>

<br />How can this be? </p>

<p>It seems to focus OK most of the time, but I many times they are clearly out of focus.</p>

<p>Comments?</p>

 

<p>Sample image with EXIF would assist.<br /> F/32 is small - what lens? What lighting?</p>

<p>WW</p>

<p>Lens is a Canon 100 Macro F2.8. <br>

<br />It doesn't seem to matter what aperture, really. Most of my people photography in the studio is shot at f5.6 and I have the same problem.</p>

<p>Is it the camera, the lens, or my technique? How on earth can I get a confirmation beep and the image be way out of focus?</p>

<p>thanks for the reply . . . sample of the OoF image, please?<br>

WW</p>

<p>William:</p>

<p>I'm afraid I don't keep the OOF images, or I'd gladly post one. I hit delete immediately and it improves my editing process.<br>

<br />It's soft, period. <br>

<br />Thanks!</p>

<blockquote>

<p>“It's soft, period. <br /> Thanks!”</p>

</blockquote>

<p>Tom:<br>

For calrity and exact meaning - I was asking for the sample for my (and other's) analysis and clues to what might be causing this ongoing problem: not to question whether it was soft or not.<br>

You initiated the request for assistance - maybe consider keeping a few soft samples if you wish to take the conversation further.</p>

<p>Period.</p>

<p>Thanks!</p>

<p>William</p>