My T1i isn't in perfect focus, probably never was :(

Started Jan 12, 2013 | Discussions thread
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SystemAgnostic Contributing Member • Posts: 530
My T1i isn't in perfect focus, probably never was :(

So, I've been ignorant of photography for years, happily snapping away.  In late 2009 I got a T1i, and was using old film SLR lenses - a Tamron superzoom and a Canon 28-90.  I was happy with the way photos were coming out.

Now, in the past month or two months, I've gotten the photography bug, and have been reading and learning more.  I've been looking at photos as 100% zoom, and realizing that a lot of them are a little out of focus.  Most of them.  This was frustrating.  Spurred to action, assuming it was the cheap & old lenses, I bought a 50mm 1.8 lens for the T1i.  Pictures are sharper, and it can shoot pictures indoors I never dreamed of before.  BUT, focus issues seem to remain.

So this morning I took some test shots of a focus template.  I followed instructions of single focus setting and focusing on the center spot.  My findings:

The Tamron lens, which I used almost exclusively, is front focusing at about the 50mm point.  Tested at the highest aperture of 4.5.  Ack!

The old Canon lens is front focusing at about the 10mm point.  Tested at the highest aperture of 4.5.

I took a lot of test shots with the Canon 50mm prime.  It appears to always front focus some, but the point changes based on aperture.  At a aperture of 1.8, the front focus point is about 25mm.  Perhaps a little closer to 20mm when tested at aperture of 2.5.  And gradually closer to perfect as I approach aperture 4.  Meaning - at aperture 1.8 - the 40mm marker and 10mm marker are equally blurry, and just around 25mm seems perfect.  At aperture 2.5, the 10mm marker and 30mm marker are equally blurry.  At aperture 4, a lot more is in focus of course, and about the -30mm and the positive 40mm markers are equally blurry- a front focus of a little.  I didn't believe it so I retook test shots with the same result.  Not only is more in focus at aperture 4, but the center area of focus seems to be more in the ideal location.

First, since all lenses appear to front focus, the camera adjustment seems to be off.  I'm pretty upset this has been the case for three years, and all my photos are sub-optimally focused.  This stinks!

Second, I get the feeling this is pretty common place.  I'm amazed that not all DSLRs have micro focus adjustment ability.  $600 for a dslr and they can't include the code which allows you to take good pictures with any lens.  Hogwash!

Third - does it make sense that the aperture impacts the focus point?  At lower apertures the focus point appears more perfect to center?

Fourth - what can I do?  Sending the camera for repair to Canon might cost quite a bit - I don't know if it would be worth it.

 SystemAgnostic's gear list:SystemAgnostic's gear list
Canon PowerShot S100 Panasonic LX100 Canon EOS 70D Panasonic Lumix DMC-GX85 Sigma 50-150mm F2.8 EX DC APO OS HSM +5 more
Canon EOS 500D (EOS Rebel T1i / EOS Kiss X3)
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