tip on 40D

Yes i just bought a 40D and with all this focusing promblem going around its getting me kinda worried with my new camera im just starting this field with SLR cameras my first was a Xti.But what i was wondering how do i find out if my camera doesnt focus correctly im going on a shoot with my camera this weekend to see if its working properly what can i take pictures of to find out if my camera has great AF im a scenery nut so i want my pictures to be sharp sharp and not out of focus p.s i have a 18-55 3.5 kit lens and a 28-135 IS 3.5 kit lens Thanks so much for your help

Did you have any problems focusing with your XTi?

Well the thing is i havent had time to take test pictures with my 40D yet

silverwolf wrote in post #4280650
Yes i just bought a 40D and with all this focusing promblem going around its getting me kinda worried with my new camera im just starting this field with SLR cameras my first was a Xti.But what i was wondering how do i find out if my camera doesnt focus correctly im going on a shoot with my camera this weekend to see if its working properly what can i take pictures of to find out if my camera has great AF im a scenery nut so i want my pictures to be sharp sharp and not out of focus p.s i have a 18-55 3.5 kit lens and a 28-135 IS 3.5 kit lens Thanks so much for your help

I was asking about your previous camera, the XTi.
Not 40D.
Did you have problems in the past, focusing with your old camera, with XTi?

silverwolf wrote in post #4280650
Yes i just bought a 40D and with all this focusing promblem going around its getting me kinda worried with my new camera im just starting this field with SLR cameras my first was a Xti.But what i was wondering how do i find out if my camera doesnt focus correctly im going on a shoot with my camera this weekend to see if its working properly what can i take pictures of to find out if my camera has great AF im a scenery nut so i want my pictures to be sharp sharp and not out of focus p.s i have a 18-55 3.5 kit lens and a 28-135 IS 3.5 kit lens Thanks so much for your help

Your sharpness will result from a combination of lens sharpness and focus accuracy. It's not easy to test focus sharpness unless you have a reliably sharp lens, such as a fixed 50mm-series lens. A 50mm f/1.8 is quite inexpensive, and if your really want to check sharpness out might be good for that as well as a very worthwhile fast lens for your kit.

If you want to check overall sharpness with your two lenses, you will need a tripod and things to take pictures of with good detail and enought contrast to trigger the camera's autofocus. I myself would set the camera to use mirror lockup to prevent vibrations from messing things up. Set your subject/s up to be reasonably well-framed and then take a series of pics with each lens at several aperture settings, from wide open to the smallest, and compare in your software at 100%. Most of them should have a "look of sharpness" although at 100% digital RAW images can use a touch of sharpening to bring out the edges. If you're shooting jpeg, the camera applies some sharpening.

Where you will notice a difference most likely is at the two extremes of aperture opening. Many if not most lenses are softer at the wide open and smallest apertures.

If all the images seem "bad", it may be a camera problem or it may be your perception of what sharpness should be. With your two lenses being zoom non-L lenses, they will not be as sharp as a good fixed lens like the 50mm, so you may want to pick one of those up. Try doing some sharpening on the images and see if your perception of the sharpness improves.

That should be enough to get you started, but in the meantime, get out and take some pictures! If you're happy with your pics, then no problemo!

Sorry my Xti focuses very well i dont know about to 40D yet i had one bad shoot with that but i think it was user error i hope

I can't believe you posted this. Why not try taking a picture before you complain. Don't let a few people who have problems cloud your new camera experience. There are many many more happy users.

silverwolf wrote in post #4280910
Sorry my Xti focuses very well i dont know about to 40D yet i had one bad shoot with that but i think it was user error i hope

So, shoot just the same way as you used to shoot with your XTi, with same lenses..
Compare pictures.
Only if you find any problems, think about solutions..
If everything is OK, no need for testing..

Go try it out, the only way you'll know if there is a problem is if you use it.

This may be on of the few times when it's appropriate to "shoot first and ask questions later."

Mark

elader wrote in post #4280936
I can't believe you posted this. Why not try taking a picture before you complain.

Geez.

Silverwolf, most of us aren't as snappish as that.


There isn't a "focusing problem" with the 40D, actually - the 1D mark III has a genuine focusing problem, as you'll see if you read the 253,942 MK3 posts on POTN.

Some 40Ds have front- or back-focus, but it appears to be ordinary production tolerance variations. We see these because Canon doesn't actually test the cameras for focus before shipping them - that's our job.

From several polls and lots of messages on POTN, it looks to me that about 5% of the 40Ds have focusing problems. AFAIK all of these can be cured by simply testing and adjusting the bodies.

Too bad we have to do this, but that's the way consumer electronics are manufactured and marketed. And it's why we get such great toys at such low prices.

-js

I don't have a 40D, but would be willing to bet that 9 out of 10 who experience focusing problems are actually user error, and not anything wrong with the camera. Even so, there simply haven't been a large number of problems reported.

First of all, after all the hullabaloo about the 1D Mark III focusing issues. Maybe we're just a little predisposed to look for similar issues in the 40D. But, it uses an entirely different AF system.

Another key factor, it's difficult with any of the crop sensor D-SLR to judge depth of field or precise point of focus in the viewfinder. For one, there is much more apparent DOF looking through the viewfinder, than there is in reality. This is actually true to a lesser degree with all full frame DSLRs, and has been true with all 35mm film SLRs since the beginning.

Now, your lenses aren't particularly fast and don't render super shallow depth of field in most circumstances (they will give fairly shallow DOF at their closest focus). So, just use the camera and learn its controls, stop worrying about it.

If you want to really nail focus, set up with One Shot to use a single AF point, usually the one in the center, then use the AF On button to achieve focus, reframe as needed and take the shot.

I've heard and read far more reports that the 40D has faster and more accurate AF than it's predecessor, the 30D (and both of mine are pretty good), than reports of problems.

Sure, there are bound to be some small number of units that get out without proper calibration or maybe get bumped out of adjustment in shipping. That's to be expected in a precision, mass production item like a camera.

But, really, which is more likely... The 40D has focusing issues in a lot of copies? Or new owners just aren't very good using them at first?

Go shoot pictures and learn how to use your new camera!

Thanks for all your help and your right i do worry too much.

number six wrote in post #4281249
Geez.

Silverwolf, most of us aren't as snappish as that.


There isn't a "focusing problem" with the 40D, actually - the 1D mark III has a genuine focusing problem, as you'll see if you read the 253,942 MK3 posts on POTN.

Some 40Ds have front- or back-focus, but it appears to be ordinary production tolerance variations. We see these because Canon doesn't actually test the cameras for focus before shipping them - that's our job.

From several polls and lots of messages on POTN, it looks to me that about 5% of the 40Ds have focusing problems. AFAIK all of these can be cured by simply testing and adjusting the bodies.

Too bad we have to do this, but that's the way consumer electronics are manufactured and marketed. And it's why we get such great toys at such low prices.

-js

I took a LOT of pictures testing mine after the first day when I wasn't totally happy. I had to prove to myself that it wasn't user error.

Canon have repaired it and it is now excellent.

amfoto1 wrote in post #4281479
I don't have a 40D,

That was probably all you needed to say.