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Home: Video University Forums: Digital Photography for Videographers:
weird focus issue

Shadow
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Mar 7, 2008, 11:22 PM

Post #1 of 9 (648 views)
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weird focus issue	Can't Post

The last wedding I shot using mostly a Canon 20d and the 24-70mm L-series lens. The weird thing I'm noticing is that the shots that I took zoomed in are nice and crisp, but if I took the same shot only zoomed out the photo is softer.

I'm rather particular about focusing so I don't think it is that I misfocused somehow, as it is happening throughout all the day's photos, anything wide is softer than anything zoomed in.

Has anyone seen this before?

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Sparky
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Mar 8, 2008, 12:37 AM

Post #2 of 9 (642 views)
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Re: [Shadow] weird focus issue [In reply to]	Can't Post

As popular as it is ... there are a lot of photographers that have had problems with this lens back-focusing. I don't know if that's the issue or not. You might zoom in on some of your files and see if you can find something in the photo that is in focus.
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Shadow
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Mar 8, 2008, 10:10 AM

Post #3 of 9 (625 views)
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Re: [Sparky] weird focus issue [In reply to]	Can't Post

Thanks Sparky, I'll try that.
Do you know if it is something that can be adjusted if the lens is sent in?

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Jenn M
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Mar 8, 2008, 12:39 PM

Post #4 of 9 (615 views)
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Re: [Shadow] weird focus issue [In reply to]	Can't Post

I had the same issues - sent it to Canon for calibration. Seems to be fine now.
-jenn

Shadow
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Mar 8, 2008, 1:59 PM

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Re: [Jenn M] weird focus issue [In reply to]	Can't Post

Thanks Jenn
I'll send it in, luckily it is before wedding season really hits. :)

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anniec
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Mar 10, 2008, 1:08 AM

Post #6 of 9 (583 views)
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Re: [Shadow] weird focus issue [In reply to]	Can't Post

I have to send my Canon XL video lens in every 2 years to correct this problem as well. Hope it doesn't cost as much with a photo lens!

RustyB
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Mar 10, 2008, 11:25 AM

Post #7 of 9 (559 views)
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Re: [Shadow] weird focus issue [In reply to]	Can't Post

Have you downloaded this focus test chart that someone made? Maybe it would help to see if it's a focus problem or the lens is just soft?

http://www.focustestchart.com/chart.html

Good luck, I hope it doesn't cost much to get repaired!

savvy houston bride
get a video....not an excuse

Shadow
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Mar 10, 2008, 4:28 PM

Post #8 of 9 (541 views)
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Re: [anniec] weird focus issue [In reply to]	Can't Post

Oh blech - don't tell me that!

Frown

Hopefully it is a one time fix.

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Shadow
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Mar 10, 2008, 4:36 PM

Post #9 of 9 (539 views)
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Re: [RustyB] weird focus issue [In reply to]	Can't Post

That's Rusty, I was looking for a page like that. Lots of good info there on how to test.

I noticed that a section of shots were taken at 800iso by mistake, so the grain might also have something to do with it all being slightly soft.
And in addition to that, I had picked up the 10d, which is ony 6.1 mpixels and the ettl popped off the dress making that perfectly exposed but left the rest of the picture slightly darker and needed to be lightened. I shot in RAW but still, at 800iso on a 6.1 megapixel camera.... Good thing it was only a few shots, the lcd preview looked ok on the camera, I guess I should have double checked with the histogram - or better yet, checked my ISO!!

I'm going to test that lens and the 20d again just to make sure, but after reviewing the specs on all the raw shots through digital photo professional I could see what settings I had on each photo which helped me diagnose the problem areas.

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