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Old Sep 2, 2007, 4:34 PM   #1
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Need adivice:

I bought my first KM D5D around November last year, I am happy with the results from it since then. I have put my 50mm F1.7 on it and pictures are sharp from F2.8, but a little loose at F1.7 to F2. I think it is normal at max aperture on all lenses. I also tried the Tamron 20-40mm F2.7-3.5, the pictures are sharp from 24mm and up but loose below 24mm, even with smaller apertures not help. I also think this is normal, I can not ask to have the same perfect results of the G lens. Then I bought my second D5D from Ritz three months ago as demo unit with low low price $375, I did not use it for three months until this labor day holiday, but it makes me shock. I use it with the same 50mm F1.7 and the Tamron 20-40mm above, these two lenses do not have any unsharp pictures as I mentioned above at all. Both D5D have the same firmware version 1.00 u. I also discoved that when I set to continue shooting mode (the finest JPEG), the first D5D start to slow down after 7 pictures, but the second D5D can continue shoot to 20 pichtures than start to slow down. Both use the same Lexar 8GB 133x CF card, both set the anti-shake on. Questions are: Is my first D5D defected? Will SONY repair it or exchange for the A100 (I wish)?
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Old Sep 2, 2007, 9:29 PM   #2
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Are you sure the settings are the same for everything? I could perhaps see the Autofocus alignment being off causing some issues (although that doesn't happen too often with the 5D versus the 7D).

But, for one camera to take far more photos before slowing down seems pretty odd unless a setting is very different somewhere. For example, one set to jpeg fine and the other set to jpeg extra fine, or one set to a lower resolution compared to the other (3MP versus 6MP)

I'd try them both in exactly the same conditions with the same subjects, making sure all settings are the same (including drive mode, metering mode, focus mode, focus point, etc.) and make sure they really are different before jumping to any conclusions. You may want to swap the battery between them, too (in case you have a battery voltage issue that may be impacting camera operation).



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Old Sep 3, 2007, 1:40 AM   #3
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Thanks JimC, both camera do have the exact same settings, battery is fully charged, focus and metering settings are the same. I actually do not care much on how many pictures that the continue shooting mode can shoot, but I really care of the focus problems on those two lenses. Do you have any ideas what causes that? Will SONY repairthe first camera?
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Old Sep 3, 2007, 3:59 AM   #4
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My KM5D was not correctly focusing so I had this sorted out for me under the warranty, however now yours is out of this you will probably have to pay for it to be done.

As for the continuous shooting that is a really strange one and not something I've heard about before.
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Old Sep 3, 2007, 7:11 AM   #5
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Have you tried a focus test chart to confirm that the camera is not focusing correctly? You can find one here:

http://focustestchart.com/

Have yo tried swapping CF cards between the two cameras? There are reports around of fake/clone cards. Hopefully you didn't have the misfortune to get one of those cards.
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Old Sep 3, 2007, 9:15 AM   #6
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Quote:
I have put my 50mm F1.7 on it and pictures are sharp from F2.8, but a little loose at F1.7 to F2. I think it is normal at max aperture on all lenses.
Yes, most lenses are a bit sharper stopped down a bit, especially lenses with wider available apertures.

Quote:
I also tried the Tamron 20-40mm F2.7-3.5, the pictures are sharp from 24mm and up but loose below 24mm, even with smaller apertures not help. I also think this is normal
That doesn't sound right, unless you're just seeing a curvature of field problem (which is my guess). Most wider lenses do not have a flat focus plane. It's in a curve. BTW, that Tamron just happens to be one of the sharpest wide zooms ever made. It even tests sharper than the Minolta 20mm and 24mm f/2.8 primes, at f/2.8, and it's sharper than many wide zooms costing much more from other manufacturers, even at wider apertures. It is better stopped down though (as most lenses are)

http://old.photodo.com/prod/lens/tamron.shtml

More MTF charts here:

http://old.photodo.com/nav/prodindex.html

But, you do see some variation between lenses, and how a camera's Autofocus behaves with a given model also comes into the equation, since it's got to look at things like focal length and more to determine how much tolerance it has for the AF settings for a given aperture, and how much rotation of the focus ring is needed to achieve a sharp photo (since cameras may not verify the final adjustment to increase focus speed).

So, third party lenses sometimes have problems with accurate AF due to the way they're chipped internally (the firmware in the lens itself and how it reports back to the camera), and manufacturers often change the lens firmware during a production run.

Even lighting temperature can impact Autofocus, as the sensors can react differently in different lighting depending on the lens characteristics. Make sure you remove any filters that could be causing an issue, too. BTW, I've got a Gold Ring version of the Tamron SP 20-40mm f/2.7-3.5 AF lens, and mine works fine, even wide open. Interestingly, the older versions of this lens (without the Gold ring) tend to have the best reputation with KM DSLR owners.

Make sure it's really focus error and not user error (i.e., focusing in front of or behind your subject because of the focus point being selected, reframing too much after focus lock, leaning after focus lock, etc.). If you are not testing both cameras in controlled conditions, then you may be wrong that one has problems that the other doesn't. There are too many variables involved.

Make sure it's not something *real* simple, too (i.e., you left the AF/MF switch in the MF position). I've done that before. It happens. :-)

Also, make sure it's not something simple like a shutter speed issue causing blur. *Most* of the posts I see from members that think they have a focus problem is because of blur from shutter speeds being too slow. You may have something like ISO Speed set differently between cameras impacting it.

Are you selecting your focus point or letting the camera do it?

Your description sounds a bit like you're trying to use an outside focus point at the wider end of that Tamron at close subject distances and still expecting the center to be sharp (or vice-versa). Wider lens have a lot more curvature of field compared to most standard or longer focal length primes. Reframing after focus lock can exaggerate that problem, too.

http://www.mhohner.de/recompose.php?lang=e

http://www.outbackphoto.com/workshop...y06/essay.html

One way to check it is a focus chart (as FrankD mentioned). It's best to use a 50mm f/1.7 to check it. Use a tripod as any movement can throw it off.

Another way to test it is by setting up some books, CD Cases or similar subject on a table, spaced closely together. Then, focus on the one in the center. If the book in front of the one you're focusing on is sharper, you've got front focus (the camera is focusing in front of your target). If the book behind the one you're focusing on is sharper, you've got backfocus (the camera is focusing behind your target).

Here's an example of what I'm talking about, where I'm focusing on a book in the center (the one that mentions how to "lose a dress size in a 4 weeks". :-)

I just grabbed some of my wife's books to check it real quick, not long after I got my 5D. Note how the book just in front of it and just behind it have blurrier text? IOW, mine is fine (my focus point is the sharpest).

http://www.pbase.com/image/51015183/original.jpg

The last I heard, Precision was charging a flat rate of $281 to fix these cameras. They use an AF adjustment program and test targets to recalibrate the Autofocus if needed.

But, I've seen posts from multiple 7D and 5D users that got their camera working simply by adjusting the AF sensor alignment screws. This is a controversial procedure, since it only adjusts the AF sensor alignment, without regard to the AF tables internally used for different lenses, mirror alignment or other adjustment points. Their primary function is to correct pitch and yaw versus backfocus or front focus. I can only say that I've seen multiple people claimed it fixed their issues with about 15 minutes work adjusting them. See the last 3 posts in this thread for 5D owners that claim it fixed their backfocus issues, and I've seen a number of posts on various forums from 7D posters claiming the same thing (they fixed their backfocus issues by adjusting all 3 screws equally clockwise by a small amount).

http://www.dyxum.com/dforum/forum_po...=5628&PN=2

If it were my camera, I'd do that versus sending to Precision and spending $281to let them do it using more sophisticated methods. But, try it at your own risk.

Here's how if you want to give it a shot (of course, make sure you really do have an issue first by testing with the 50mm f/1.7 in controlled conditions):

Remove the plate that's around the tripod mount (it will pry off), and by all accounts I've seen, the adhesive is good enough to allow it to "restick" later.

You'll find 3 hex screws under this plate that you can adjust using a 1.5mm hex driver. These are for the AF sensor alignment. The adjustment is *very* sensitive. Usually only about 1/4 to 1/3 turn is needed to correct even serious backfocus issues. Do not attempt to turn just one screw. You'll want to turn them all equally. Othewise, you'll end up with a tilted AF sensor assembly (for example, one focus point backfocusing, another front focusing)

If it's backfocusing (which is the most common problem), I'd set the camera up on a tripod (this is important, as any movement can throw it off at wider apertures) using the 50mm f/1.7 at a wider aperture setting, using staggered books or similar items as in the image I posted a link to, making sure to focus on the center book (select the center focus point to do it).

Take some test photos and see if it's back focusing or front focusing. If it's back focusing, turn all 3 screws approximately 1/4 turn clockwise and take more test shots and see if you've got it nailed or not, adjusting more or less until it's perfect. If it's front focusing, turn all screws counter clockwise by the same amount.

As for the performance issue, that doesn't sound right either. If you're shooting JPEG Extra Fine with the drive mode set to continuous (there is a button on the top of the camera controls drive mode), the buffer is only designed to hold about 6 or 7 shots before it slows down to around 2 frames per second with a fast card. So, if you're getting 20 frames before the camera slows down, my guess is that you have the image quality (or resolution) set differently on one camera (perhaps using 3MP verus 6MP, or fine versus extra fine).

I haven't tested mine with a newer Lexar like your 8GB 133x cards though. My fastest Lexars are older 40x Lexar Platinum models, and my fastest cards are Sandisk Ultra IIs. As a general rule of thumb, 4GB and larger cards do tend to be a bit slower though, compared to a 2GB or smaller card using the same component types (because 4GB or larger cards use a FAT32 versus FAT16 file system).

Also make sure you're shutter speed isn't impacting it (if your shutter is open longer, your frame rate will slow down). So, use either manual exposure with a fast enough shutter speed, or test it in good light versus indoors.

Is the same card you're using in both cameras, or just the same brand/model? Check it with the same card, as one could be slower than another. Card manufacturers sometimes change components in a card model during a production run, and that can impact how well one works with a given camera. How a card is formatted will also impact it. It's best to format one in the camera you plan on using it in. I do this *every* single time I reuse a card (format it with the camera's menus for format, not a PC), No exceptions.


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Old Sep 3, 2007, 10:27 AM   #7
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P.S.

You may also want to reset your cameras back to factory defaults. You'll find two separate menu choices for that purpose. One is under the Custom Settings menu and controls custom settings. The other is under a Setup menu and should work for everything. I'd use both reset choices. That way, you'll know the cameras are more likely to be set the same way (and my guess is that they're not).

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Old Sep 3, 2007, 7:36 PM   #8
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Thanks all of you for the instructions, I have reset both cameras and use the same battery, same CF card, same settings, but the results are still not the samefrom the Minolta 50mm and Tamron 20-40mm. The first D5D is still having blurry picture at F1.7-F2.2 on the 50mm lens and 20-22mm on the Tamron 20-40mm lens. The pictures from the second D5D are all sharp..sharp..sharp... Please advice.
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Old Sep 3, 2007, 7:45 PM   #9
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Same advise.

Check the Autofocus to see if it's backfocusing (focusing behind your intended subject) or front focusing (focusing in front of your intended subject) using either a test chart like FrankD posted a link to, or a something like books staggered at different distances to the camera as shown in the link to an image where I checked my 5D that way.

If it's bad (front focusing or backfocusing), then decide if you want to spend about 15 minutes to try and fix it yourself (see my instructions above, which is what I'd do if it were my camera), or let http://www.precisioncamera.com/ adjust it using more sophisticated techniques. That would cost you $281 ($269 + $12 shipping and handling) for an out of warranty camera.

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Old Sep 4, 2007, 3:05 AM   #10
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Thanks for JimC's advice, I spend the whole evening to follow your instructions step by step, I have the following results:

1. I really set the resolutions of the second D5D to fine instead of extra fine, no wonder it has so great performance, sorry for the confusion.

2. The auto focus system of the first D5D really has problem. The focus was about 5mm far away from the focus point on the 50mm lens and the Sigma 30mm F1.4 at 1.4, but it was unstable when I test the Tamron 20-40mm at 20mm, the focus was off from 5mm to 50mm, sometime FF sometime BF.

I set the cameras to spot area AF and spot metering. The lenses are set to maximum aperture.

Since the focus was off unstable, I don't know that I can make the adjustment or not, would you please give me some advices? Thanks again.
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