10D and Focus. Some things I've learned.

[CyberDyneSystems]

To date I have shot 13,708 images with my 10D. It wasn't untill after the first 10,000 that I really began to worry about the times that images are out of focus.

Here a few things that I have noticed with my aprticular 10D nad my lenses.

1. Even high quality filters can cause problemsRecently I was concerned abpout the focus on my Sigma 70-200mm. I knew that it HAD been spot on in the beginning. I used it for a fashion show right out of the box and was really pleased. But a few months later I kept having back focus trouble.

It turns out that it was caused bu the UV Filter!!!! If I take off the Hoya UV filter the lens and camera focus fine. This in keeping with my fashion show experience as I did not have a filter yet when I shot that show. Understand that the filter doesn't throw off the focus 100% of the time. But it does do it under certain conditions.

I wonder how many 10D owners can fix there focus problems by removing the UV or skylight filter?

2. This one really bothers me... The 10D absolutely BLOWS if you are shooting with a long telephoto and the sun is at your back!!!!!!!!

With my 50-500mm or 70-200mm if i am shooting on a sunny afternoon,. (this is a tough time anyways) about 85% of the pictures I take with the sun at my back will be poop!

Two things happen under these circumstances.
First the focus is pants.

Second,. the metering allways wants to blow out the subject (even with "partial" metering selected)

Truly I mean this,. 85% of the time this happens.

Mind you,. we are talikng about long telephoto shots. If the subject closer,. these symptoms tend to be less troublesome. Oh the focus will still be off some of the time but as you get closer the percentage of toss out shots goes down.

I wonder if this is true of all Cameras and I am just trying to take shots I shouldn't?

Any way,. I know if I can avoid these two situations I can get much better photos.

[lightandlife]

If UV filter is culpable, did you or anybody else have a similar focusing problem when using D30 or D60 with a UV filter?

[CyberDyneSystems]

I haven't done any testimg beyond using the lens yesterday,. noticing it was doing the "out of focus thing" again,. and taking off the filter right then and there and suddenly everythinmg was fine again...

[Belmondo]

CDS:
That's really interesting. Have you noticed any problems with polarizers?

Tom

[Vegas Poboy]

I would like to know what model of Hoya UV filter you are using? Right know all of my lense are using the HMC version of hoya.

[D60DIETER]

Thanks CDS,

I will go today and take pictures without and with filters. I often use polarizers and greyscale filters and sometimes I had a thought comming over me that somethings happpening with the focus of my pictures that I could not discribe.

I try to figure out more bout that issue.

Dieter

[Mark Kemp]

I have noticed a similar effect with some lenses. Especially my older Canon 35-105 and 75-300.

The focussing performance is generally poorer with these lenses on my D30 or film slrs. Sometimes they hunt or just go to one end of the focus travel and stay there.

I removed all the UV filters and the focussing got better sometimes.

I cleaned the lenses thoroughly and this helped as well, but it still happens.

I wonder if the USM motors are getting a bit old and worn as they seem louder and rougher or perhaps I am just expecting too much as I now normally use more expensive lenses and am used to them.

I also wonder if the combination of smaller lenses, a UV filter and some dirt is reducimg the light reaching the focus sensor.

I spoke to a friend about this and he said he never uses UV filters. he doesnt want any glass (however good) in front of a lens that he has paid a lot of money for. He would rather just be careful not to damage the lens.

I have been following his advice, but only for a few weeks. I don't keep a filter on my lenses all the time any more and I clean them more often and take care not to scratch them. So far so good, no damage and no majoe focus problems, but I don't use the older lenses much anyway so its a bit early to tell.

[CyberDyneSystems]

Vegas Poboy wrote:
I would like to know what model of Hoya UV filter you are using? Right know all of my lense are using the HMC version of hoya.

Vegas,
The Filter simply says "HOYA 77mm UV Philippines "

I do not think it was one of there super muticoated ones. It was bout $70.00 if I remember...

BUT I don't think the specifics mean anything.

I guess the point is that what I KNOW is that this filter on this lens on My camera can cause problems with focus. I would not expect that this means that UV filters will allways cause focus problems,. but I DO think that it may be of help,. in that it gives anyone reading this something to test for themselves.

For my part,. I take my lenses into harsh environments regularly,. so I have hoods and filters for protection. But if I become aware of a foucs issue,. I will remove the filter and see if that fixes things.

[Webster]

I had a Sunpak circular polarizer for my 75-300 IS lens. It worked fine with my Elan 7e but when I switched to the D60 it became impossible to focus. There was no suble back or front focus here. It was clear from the first glance through the viewfinder that nothing was in focus. I switched to a Tiffen polarizer and it has worked fine ever since. Now it may be that the Sunpak wasn't even a circular polarizer (but then it shouldn't have worked on the Elan) but it may also be that whether a particular filter will work on a particular camera depends on the astrological birth sign of camera and filter.

The manual for Canon's 17-40mm lens states that "Although the lens is dust- and water-resistant, a filter must also be attached to the front of the lens for complete protection". It also says "If you need a polarizing filter, use Canon's 77mm PL-CII polarizing filter". I normally dismiss vendors' insistence that you use their products as marketing hype, but in this case I'll probably do what they suggest.

I'm starting to really wish filters came with a quick-release mount.

[Vegas Poboy]

Thanks for the Info CyberDyne,
I was just curious to know what brand of filter. I have UV filters fo all of my lense and usually its Hoys midgrade. I'm still waiting for the arrival of my 70-200 f/4 but as of now I have not seen a problem with my 17-40. Most likely once the other lens arrive I'll go out and do a full test shoot and if I see a major difference I'll post the info.
Again thanks for the info its better to remove a filter or purchase a better one instead of shipping the camera to Canon.

[xxlt]

CyberDyneSystems~~Hello :)
I've been following this thread with much interest.
Here's a link on another forum about the same topic:
http://forums.dpreview.com/forums/read.asp?forum=1029&message=6215451

Thanking GregL281 for taking the time to put this together.

bill from Ohio w/D300

[lightandlife]

OK, I am going to remove all the UV filters from my lenses.

I never broke or scratched any lenses so far. But the UV filters are ruining the pictures or at best obscures with no recognizable benefits. Should any lens break, just buy another. It rarely happens. But all the pics with the filters are compromised. Let us throw away UV filters!

[slejhamer]

CyberDyneSystems wrote:

The Filter simply says "HOYA 77mm UV Philippines "



CDS: Interesting observations. The folks at the Filter Connection ( www.2filter.com) told me that the Philippines-made Hoya glass is poorly made, so this might certainly be the cause of your problem. I use a Hoya S-HMC UV(0) on my 50mm Canon lens and I will swear that it focuses better with the filter than without (though I haven't tested. ;) ) I used that filter plus a cheapo Sunpak polarizer in the gull shots that you commented on in Share Photos. No focus problem that I can detect, and no chromatic abnormalities either.

Given the results in the dpreview thread that xxlt posted, it's clear (pun intended) that some filters can cause a real problem, but I'm quite pleased with my particular Hoya filter.

[lightandlife]

Slejhamer, here is an interesting test of whether any fiter adds something to the image or creates a focusing problem.

Of course, we don't want to add any stuff on the images the lens brings to the camera, right?

Pile up, in front of an L lens, say 5 Hoya or any other filters that you swear will not add anything, and see if the filters degrade any images. If you do not see any difference, then the filter adds nothing for practical purposes. If they add something, maybe one filter will also add something. If 5 filters create an autofocusing problem, then one is also likely to do that, except that the problem may be less noticeable.