Two pictures both alike in dignity...

[matthijs]

<p>Both look sharp until you zoom in at 100%.</p>

<p>I recently bought a 50D. The following pictures are both shot with my 70-200/F4L IS.</p>

<p>My issue is this; about 90% of my shots close to the minimal focus distance are not really sharp but 10% are.</p>

<p>My uninformed guess is motion blur but I'm not sure.</p>

<p>Here I post 2 shots both at ISO 100, F5, 1/400 aproximately 1,5 meter distance (5 foot). One of them is at 183mm the other (the sharp one) at 200mm. I'm guessing that the difference in zoom is irrelevant.</p>

<p>Why do you think most of my shots are unsharp at 100% and some of them are?</p><div></div>

[matthijs]

<p>The sharp one (total)</p><div></div>

[matthijs]

<p>Unsharp one at 100% (top left flower, that looks sharp but isn't)</p><div></div>

[matthijs]

<p>Sharp one at 100% (The flower in the middle)</p><div></div>

[zml]

<p>The top-right flower appears to be sharp in the "unsharp" image so this is a focusing eerror most likely but it loooks like you are at (or close to) the minimum focusing distance and any combination of the following could have occured:<br />The camera (or you with the camera) moved aft/fore (and the flower was no longer within DOF)<br />The camera shake/movement<br />The flower moved aft/fore (and it was no longer within DOF) or some other flower movement has occured (wind, earthquake, stomping rhinos, etc.)</p>

[images_in_light_north_west]

<p>Actually it doesn't matter what they look like at 100 or 200%, it only matters at actual viewing size, but like Mike said, probably movement</p>

[matthijs]

<p>In reaction to Michaels post.</p>

<p>I used center point AF and panned. Maybe that accounts for the difference in this picture. But I'm not too sure about that. There's no real sharp spot in the unsharp one and with just a shift in focal plane there should be.</p>

<p>Plus my large percentage of unsharp shots also happen when I do not pan after focussing. Most of my recent testshots are of flowers in my garden and most of the time I just put the centerpoint on a piece of the flower that has plenty of detail and fire after focussing.</p>

<p>So I'd say that leaves camera shake or flower movement as possible causes in your post. (I may be disregarding camera movement too easily but I don't think so.)</p>

<p>At what point may I disregards camera shake? Is using an IS lens at 1/400 shutter enough when at 200mm on a crop camera while sitting unmoving?</p>

<p>It was a tad windy today but I seem to have the same successrate with truly static targets.</p>

<p>Note that the amount of earthquakes (caused by stomping rhino's?) are pretty rare in the muddy Netherlands...</p>

[matthijs]

<p>@Ross: well, one does want to know why one's new toy doesn't work as expected.</p>

<p>Plus, and more significantly, some of my pictures are cropped pretty rigorously and for that I need a sharp original. On my 400D this seems less of a problem than on my 50D. It's pretty important to me to know whether I should polish my technique or whether it's the camera that is in error.</p>

<p>(Whether that is a miss focus or a sensor problem or something else entirely, I'd have to find out in the latter case.)</p>

<p>Still, I do understand that 90% or more of the so called camera failures are user error. I'm just surprised that I seem to make a significant amount of errors more with my new 50D than with my old 400D.</p>

[arie_vandervelden1]

<p><em>It was a tad windy today</em></p>

<p>There's your answer. Your lens has IS but the flower does not. Solution: shoot a few frames, pick the sharpest one, then toss the rest.<em><br /> </em></p>

[nathan_meador]

<p>The DOF at F5 would be pretty shallow, so I would think any wind movement would cause a problem. You might have been leaning towards/away while shooting which IS would not help...just up/down/side to side motion. You could raise Iso to 400 and allow for a faster shutter to increase your chance for a sharper image.</p>

[bob_osullivan]

<p>It's probably due to the razor thin DOF. 1/400th should be enought to freeze a litte flower movement from breeze.</p>

<p>Try either manual focus, or select a smaller aperture for deeper DOF.</p>

[stp]

<p>I've been testing the focus of my lenses (including the 70-200 f/4) on a tripod and using a focusing chart, and I've been struck by the shallow DOF when shooting wide open, particularly (of course) with a telephoto lens. Even under very controlled conditions, some shots are right on and others are off (which is why I shoot test shots in batches). Movement and slightly misplaced focus are two likely causes for your unsharp photos. [bTW, I found two lenses, including the brand new 70-200 f/4 IS, that were so far out of focus that it was beyond my in-camera capabilities to correct; they were sent to the Canon Service Center.]</p>

[paddler4]

<p>Mathjis,</p>

<p>I think Bob nailed it: depth of field. I do a lot of close-ups of flowers, and the problem with focus is the extremely small DOF. In fact, I threw out a bunch of shots of echinops like yours last year for precisely that reason. If one part is sharp, the rest is not. And even if you find one part that you want in focus, the slightest movement throws it out of focus again. That's why Scott Kelby wrote that pleasant breezes are bad news for macro photographers. Tonight I took a bunch of macro shots of ants on peonies and threw many of them out for the same reason.</p>

<p>If you don't have enough light to close down the lens for more DOF, you can increase the ISO and accept a little more noise in return for greater DOF. You can remove some of the noise later. </p>

<p>Since you have a 50D (so do I), here is a technique that might help. Go to custom function IV, number 1 (shutter button /AF). Choose option 3. That disconnects the AF from the shutter button but leaves it on the AF-On button by your right thumb. Select only the center AF point. Focus with your thumb (it's surprisingly easy), then recompose quickly and take the shot. the shutter then will not change the autofocus. Keep your hand ready to adjust with manual focus. Of course, if you move, or if the flower does, you lose it.</p>

<p>Dan</p>

[jim_z]

<p>I also think depth of field. According to an online DOF calculator, a 180mm lens at f5 focused to 1.5 meters has a depth of field of only 6mm. At 200mm it would be even less. Hand-holding a longish lens, it is very difficult (impossible?) to restrict your body movement to less than 6mm. </p>

<p>One word - tripod.</p>

<p> </p>

[bryantan]

<p>"I used center point AF and panned."<br /><br />With a conservative DOF estimate of 6mm, I'd say you have your answer.</p>

[joel_tomaneng2]

<p>Without scrolling down, the first thought in my head was "depth of field." I think there may be a sharp yellow leaf or two on the lower right corner of the picture. I dont a tripod is going to work here, especially with an object suseptible to the wind, plus the fact that this was shot at 1/400 sec. Narrow the aperture and increase the DOF. Bracket if you're experimenting. That should do the trick.</p>

[matthijs]

<p>O.K. 6mm is less than I thought. (That said, the flower in the sharp picture seems deeper than 6mm but is pretty sharp petal to petal.)</p>

<p>When shooting objects/people a little further off there doesn't seem to be a problem but the DoF would be bigger at longer distances.</p>

<p>It nags me to think that it's totally user error but I'll try to keep that half centimeter DoF in mind when shooting pseudo macro.</p>

<p>Thanks for the advice concerning AF-on button and bracketing. That should keep me busy the coming weeks...</p>

[paddler4]

<p>One other thing might be helpful. In general, close-ups of flowers (or anything macro or close to macro) will suffer from narrow DOF unless you have a LOT of light. This is the reason for the common advice to try to compose the picture so that things of interest are close to lying on a single plane, and then position your lens perpendicular to that plane. (Also why people use flash for a lot of macro work.) For that reason, flowers like echinops, which are spherical and have no particular plane of interst, are really hard to photograph in a way that is interesting. I kept exactly zero of my attempts to photograph them last year.</p>

[robin_sibson1]

<p>"I used center point AF and panned." There's your explanation, taken togther with the point made by other posters about limited DoF in close-ups. The relatively unsharp flower is well away from the centre of the frame, the relatively sharp flower quite close to it. If you are going to examine images from a high-resolution body at 100% you cannot afford to make such approximations as those arising with focus-recompose.</p>

[andreasb]

<p>Matthijs, <br /><br />I use the 70-200mm f/2.8 IS and see this frequently. I completely agree with everyone regarding the very shallow depth of field. The closer one gets to the minimum focus distance, the shallower the depth of field is. Even at small apertures. I setup a tripod in my apartment and experimented with it using a motionless subject. The slightest change in distance (.25-.5 cm) between the camera and the subject makes a big difference in the outcome of the photo. Any very, very slight motion of the flowers in your garden will produce exactly the effect you have seen. As an experiment, you can simulate this inside your home with your camera on a tripod and a candle. Set the candle near the lens' minimum focus distance, focus on the flame and shoot away. The small air currents on the room will move the flame around enough that it will come in and out of focus. Vary the aperture and see how little difference it makes in the depth of field in the outcome so near the minimum focus distance. It is an interesting experiment. This problem gets worse with even longer lenses.<br /><br />Good luck and have fun!</p>

[joel_tomaneng2]

<p>Andreas,<br>

Interesting observation regarding the apertures minimal effect on DOF at minimum focus distance. I'll have to test this out for myself.</p>

 

[mattb1]

<p>Technique. The 50D has the tightest packaging of pixels in a Canon DSLR to date. As such, it will show up flaws that were previously covered up. The biggest being technique, then once you get that down then you will see the flaws of the lens. </p>

<p>Don't mean to bash you, I'm going through the same thing just a little different camera. Having to relearn some things. DOF is big for me because I went to FF. You may find that you can no longer hand hold and expect to get really sharp photos, same with subjects they will need to be a lot more stationary. You may find need for mirror lockup and/or a cable release. All fun stuff, but takes some getting use to if you have been spoiled with hand holding. I know I have been spoiled.</p>

<p>You may need to upgrade the lens as well. The 2.8 version of that zoom really shines and you may be able to see the difference when looking at 100%. At f8 the F4 lens is suppose to be good, but I bet you could see some difference even there. I don't know though, I have not used the F4.</p>

[desmond_kidman]

<p>You have received most of the answers.</p>

<p>For such close distance focus and recompose is not the best technique, the thin DOF can result in error when you move to recompose.</p>

<p>With such thin DOF you are prone to error anyway, even before trying to recompose.</p>

<p>Don't try to use auto focus. Focus manually on what you want.</p>

<p>Wind foils you from 2 perspectives, DOF as well as motion blur.</p>

<p>Camera shake is another issue.</p>

<p>Take lots of images and hope one will suit.</p>

<p>Use a tripod.</p>

<p>Use a wind-block behind you and on the sides.</p>

<p>Wait until a calm day. </p>

<p>Freeze with flash.</p>

<p>Try some or all of the above. Stack the odds toward your favor.</p>

 

[matthijs]

<p>I like that, stacking the odds.</p>

<p>(-:</p>

<p>Thanks again, I'm relearning as we speak!</p>

[mattb1]

<p>Technique. The 50D has the tightest packaging of pixels in a Canon DSLR to date. As such, it will show up flaws that were previously covered up. The biggest being technique, then once you get that down then you will see the flaws of the lens. </p>

<p>Don't mean to bash you, I'm going through the same thing just a little different camera. Having to relearn some things. DOF is big for me because I went to FF. You may find that you can no longer hand hold and expect to get really sharp photos, same with subjects they will need to be a lot more stationary. You may find need for mirror lockup and/or a cable release. All fun stuff, but takes some getting use to if you have been spoiled with hand holding. I know I have been spoiled.</p>

<p>You may need to upgrade the lens as well. The 2.8 version of that zoom really shines and you may be able to see the difference when looking at 100%. At f8 the F4 lens is suppose to be good, but I bet you could see some difference even there. I don't know though, I have not used the F4.</p>