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Old Oct 2, 2009, 2:13 AM   #1
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Default M42 to EOS Adapter

I've found a great deal on ebay and local store - M42 Lenses.

From what i understand there are some M42 to EOS Adapters - with and without focus confirmation.

My questions:
1. will this adapter influence the picture taking process ? For instance, let's say i have this 100 mm focal lenght lenses. If i add a 3 mm adapter ring will the image still be in focus ? the image will be sharply focused like 3 mm in front of the sensor, right ? what's the catch then with these adapters ?

2. Is there a huge difference between 'with' and 'without' focus confirmation ?
coz there's a 40 dollar difference in price!

hope you help me!

radu
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Old Oct 2, 2009, 9:26 AM   #2
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You control how sharp the image is via manual focus (turning the focus ring on the lens). With some adapter types, you may lose the ability to focus to infinity unless optical elements adding magnification are used (because of the registration distance required). But, that doesn't appear to be the case with M42 lenses on an EOS body. See the table in this article about it:

http://www.bobatkins.com/photography...focus_EOS.html

You can also run into clearance issues (where some lenses may hit the camera's mirror causing damage). From what I can determine, this is a more common issue with full frame bodies like the 5D when using screw mount lenses, and less common on Canon models using APS-C Size sensors.

Here's someone that maintains a compatibility list with a column on whether you're going to hit the mirror or not with a 5D (and it's probably a very incomplete list, so be careful):

http://www.panoramaplanet.de/comp/

But, with a Canon model using an APS-C size sensor, this is not likely to be an issue from what I've found on various sites.

As for focus confirmation, an adapter of this type "fools" the camera into thinking it's got an EF type lens attached using manual focus, and allows the camera to use it's AF Sensors to determine if your manual focus is accurate or not (since it can be hard to judge manual focus accuracy in the viewfinders found on most dSLR models).

But, you can find third party split prism type focus screens that make it easier to judge focus accuracy. On the downside, some of those will throw off your camera's metering accuracy. Here are a couple of vendors that offer them:

http://www.katzeyeoptics.com/page--C...ns--store.html

http://haodascreen.com/CanonDSLR.aspx

As for other issues impacting the "picture taking" process as you put it, in addition to needing to use manual focus, you'll have to use stop down metering (where you set the aperture ring on the lens as desired before taking the photo), using either manual exposure or aperture priority modes. That will make your viewfinder image dimmer as you use smaller apertures (higher f/stop numbers).

In addition, the camera won't be aware of your aperture setting, so the EXIF won't reflect the actual aperture being used. You may also find that many older lenses don't have great coatings on their optics. That can make them more flare prone shooting in harsher lighting with digital (especially veiling flare where you can easily get a "washed out" look to images with brighter light sources).
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Old Oct 2, 2009, 9:50 AM   #3
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BTW, you may want to compare the prices you're seeing with Gadget Infinity (a reputable Hong Kong based vendor that usually has competitive prices on lens adapters, hot shoe adapters, etc.). It looks like they have two different M42 to EOS body adapters available (including one with focus confirmation). They also sell them on Ebay:

http://www.gadgetinfinity.com/produc...5&cat=0&page=1

http://www.gadgetinfinity.com/produc...0&cat=0&page=1

You may also want to visit the Pentax dSLR Lenses forum here, as some of our Pentax users have M42 screw mount manual focus lenses and can give you opinions on the optical quality of some of the lenses you may want to try if you decide to go with an adapter for your Canon body.
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Old Oct 5, 2009, 3:03 AM   #4
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thank you! thank you!
found 5 adapter for 27 euros (ship' included) that's like 30 bucks! cool deal, huh ?
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