Out of focus - New lens or new body?

<p>Hi Guys,</p>

<p>I've just bought a 50D and 17-55 2.8 IS - my first SLR<br>

Once I have taken a picture, I zoom in on the LCD and have found that every picture has been a bit blury. This happens irrespective of aperture, ISO or shutter speed setting. It also occurs when the camera is stable, (on a table - no tripod yet), so I assume it is a focus issue. (I have tried using just the central spot sensor when taking photos, too)<br>

I've played with the lens-specific micro focus, which seems to have sharpened things up a little - I need to do some finer adjustments and further testing.</p>

<p>My questions are:<br>

1) Is this most likely to be the camera body, or the lens? Is it common?<br>

2) Do I now have to compromise image quality at one end of my zoom spectrum, or can this be fixed? (as I understand that micro focus is focal length specific).<br>

3) What would have happened if it was the lens and I didn't have a micro-focus feature, (40D, for example)? Would I be stuck with blurry pictures!<br>

Having just shelled out over £1500, I want to be certain that my gear is performing as it should. I've owned the camera and lens for 2 days, so I can still return them for a replacement, if need be.</p>

<p>Any advice is appreciated.</p>

<p>Richie</p>

 

<p>The AF system is in the body. It should be possible to have it adjusted.</p>

<p>Hello Richard,</p>

<p>Please post a sample picture.</p>

<p>Be sure to check your images on the computer to see if you have the problem and it isn't just on the camera's lcd.</p>

<p>Another suggestion would be to test the lens with only "one" focus point selected. Although we hope there isn't an issue with the auto selector being used, I have seen problems in that mode where turning it to one point has worked better overall.</p>

<p>Richard....<br /> Set autofocus to center focus in P mode. Now try manual focusing using the live view with 10X magnification in P program mode on a tripod at say the 35mm setting. To do this you need to consult the instructions, enable live view and manual focusing in live view. After you focus in live view, switch to prism view and watch the lens as you autofocus. If there is no movement, microfocus is set. Then take a series of three pictures at say -5 0 and +5 the preferred microfocus. Take three shots at each focus setting. Pixel peep at the three sets of three shots. Print out the best shot at 8X10. How does it look?<br /> I have heard that the 50D is very demanding on lenses. I am mostly shooting with a fixed focus L lens. When shooting portraits, the AF tends to focus on the nose, thus the use of center focus on say the eye, focus lock, reframe and shoot.<br /> Hope that helps,<br /> Jeff</p>

<p>Don't judge focus by looking at the image on the camera's LCD. Change type of pictures to "RAW" (big ones) and view them on your computer. If you still think they're not sharp make back/front focus test to check what's really going on (before doing so reset camera's microadjustment settings).</p>

<p>Focus test chart: <a href="http://focustestchart.com/focus20.pdf">http://focustestchart.com/focus20.pdf</a></p>

<p>Every image must be sharpened. There is a anti alias filter in front of the sensor that prevents moire patterns but also softens the photo. The sharpness is there, it just has to be brought out with sharpening or unsharp mask tools. If shooting only jpg images, there are adjustments to be made for sharpening images as they are shot. Raw images are not sharpened in camera at all, they must be adjusted on your computer. If still not satisfied, check sharpness of lens with Micro Adjustment feature.</p>

<p>f/3.5 1/100 sec<br /> ISO 100<br /> @ 55mm, with IS. - All images were shot in RAW format.<br /> Only centre focus point used and this was aimed at the zoomed area. The bottom right fern already seems to be loosing definition</p>

<p>Normal: http://i119.photobucket.com/albums/o142/20VK/normal.jpg</p>

<p>Zoomed: http://i119.photobucket.com/albums/o142/20VK/zoom.jpg</p>

<p>Both photos are after initial micro-focus compensation of +10 (out of a possible 20). Before the microfocus adjustment, the zoomed images were poor, with consistant loss of detail.</p>

<p>Jeff - I'll try that tomorrow, when I have some decent light<br /> Michael & Brian - I'll try the test chart and image sharpening software</p>

<p>Thanks so far - keep the advice coming!</p>

<p>Richie</p>

<p>The image when you zoom in on the LCD is never all that sharp - this is not a valid test of the camera/lens ability to produce a good final photograph. At a minimum, offload the photographs to your computer and inspect them there, perhaps at 25% or 50% magnification before you make any judgments.</p>

<p>Basically, the short story is that the "test" you are doing tells you next to nothing about "sharpness" of lens/body, and you are jumping to unwarranted conclusions.</p>

<p>First step: Make some photographs with the camera/lens and view then in whatever way you will normally view them, whether as prints or online jpgs or whatever. While it is <em>possible</em> that you a defective camera/lens, it is not likely.</p>

<p>If you think you still have a sharpness problem, you have several options.</p>

<p>1. Take the camera/lens back to the shop and have them check it for you.</p>

<p>2. Do your own check. Here is one approach that could work:</p>

 

<ul>

<li>Put the camera on a solid surface - a tripod would be best, but you could use a solid table I suppose.</li>

<li>Point the camera at a subject that is flat - e.g. a wall - and has good contrast (combination of light and dark) with sharp lines. Turn IS (image stabilization) OFF on your lens. Turn AF (Autofocus) ON. </li>

<li>(Ideally you would enable mirror lockup (MLU) or shoot in live view mode, put the camera on a tripod, and use a remote release to release the shutter.)</li>

<li>If you can't do the ideal, at least use the self timer to let the camera make the exposure while you are not touching it.</li>

<li>Transfer the file(s) to your computer and take a look at various magnifications. Your photo should look pretty good at 25% or 50% - though there are some variables that could affect this that I won't go into right now.</li>

</ul>

<p>Dan</p>

 

<p>As other people have pointed out - the image in the LCD display on a Canon camera will tell you s**t about whether the real image is in focus or not - you're looking at a very low resolution jpg, not the actual picture data.</p>

<p> </p>

<p>As other people have pointed out - the image in the LCD display on a Canon camera will tell you s**t about whether the real image is in focus or not - you're looking at a very low resolution jpg, not the actual picture data.</p>

<p> </p>

<p>Richard... When adjusting the camera for micro-focusing I would shoot at a large aperture as you did in your posted pictures at f3.5. I would use a tripod. I would only evaluate the point of focus for sharpness ignoring the rest of the image.<br>

To test the lens, camera for sharpness, as opposed to focusing, I would shoot at say 2 to 3 stops down from wide open, again using a tripod.<br>

Regards,<br>

Jeff</p>

<p>Jeff,</p>

<p>DSLRs AF <em>wide open</em> in all circumstances - it doesn't matter how much you might stop the lens down (or not).</p>

<p>Also, testing sharpness by stopping down is arguably misleading, because most lenses will be sharper stopped down.</p>

<p>Richard,</p>

<p>I know you've said that you were on centre point AF, but it seems to me that detail on the left hand side of the wide image is clearly sharper than <em>what appears to be </em> the focus point.</p>

<p>Keith... I am aware that AF is wide open. Let me try to explain further. IMHO, the live view method that I outlined is used to determine the initial microfocus adjustment. The final adjustment is made using a series of three images taken at wide open aperture at say -5 0 and +5 about the intial live view microfocus point for a total of nine images. One then can pixel peek at the series of images and decide the best final microfocus adjustment. I am also aware that stopping down the lens 2 to 3 stops is more likely to produce a sharper image. The camera should be capable of producing a sharp image when the microfocus is properly set and the lens is stopped down 2 to 3 stops from max aperture on a tripod. If not, then there is probably something wrong with the lens or camera.<br>

Jeff</p>