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Author Topic: Canon Conversion to Sony a7Rii - Help Please  (Read 6076 times)

tad1973

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Canon Conversion to Sony a7Rii - Help Please
« on: August 14, 2015, 11:44:40 am »

Hello,
I'm am seriously considering the purchase of a Sony a7Rii camera to use with a Metabones IV adapter along with my Canon L series glass. I shoot landscapes exclusively using low ISO 100. I had some questions I was hoping people might be able to assist me with:

1.Can I expect to have image degradation using the adapter? Meaning, would the corners\edges of the image be blurry (due to the adapter) compared to using Canon glass on Canon body?
   
2. Does the adapter change the field of view in any way (I've never shot with adapters before)? If I was using hyperfocal distances would that still be the same for a 35mm full frame sensor(.03) using a Sony camera, Metabones adapter, and Canon glass. Or does that change in any way due to using the adapter?

Thank you!
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Slobodan Blagojevic

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #1 on: August 14, 2015, 11:54:10 am »

Since Sony is mirrorless, adapter simply replaces the space a mirror chamber occupies in Canon. Thus there should be no adverse effect on the image and everything should be the same.

spidermike

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #2 on: August 14, 2015, 12:39:11 pm »

Image quality and FOV are exactly the same as on a native Canon body. As Slobodan says - the adapter is there to mimic the flange-to-sensor distance in the native Canon body and also has the electrical contacts to maintain AF and metering. These particular adapters have no glass in them so there are no additional surfaces to affect light transmission.
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NancyP

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #3 on: August 14, 2015, 03:25:08 pm »

The only issue might be slightly off-axis flanges, as with any adapter. This can make a difference for some types of photography, but most people won't be shooting subjects where small manufacturing problems with adapters make a difference. Mount a 21mm f/2.8 lens on adapter, set to f/8, you will have so much depth of field that off axis effect won't be noticed. I suspect that the #1 issue with specific adapters will be the quality of electronic pass-through. German/Swiss Novoflex air and Chinese air are identical optical elements.
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ErikKaffehr

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #4 on: August 14, 2015, 03:45:40 pm »

Hi,

Mechanical tolerances may be a problem.

I don't agree with Nancy that depth of field with wide angles will cover up skewness in adapters. But really, there should be no skewness in adapters 0.01 mm is not critical and more than that is probably no good workmanship.

Some adapters are to short, so the lens will focus beyond infinity. So infinity stop should not be trusted with adapters. Jim Kasson has found that very few adapters maintained infinity focus correctly and those were coming from Kipon, Novoflex belonged to the worst offenders.

Any play or sagging in the mounts will add up of course.

Best regards
Erik

The only issue might be slightly off-axis flanges, as with any adapter. This can make a difference for some types of photography, but most people won't be shooting subjects where small manufacturing problems with adapters make a difference. Mount a 21mm f/2.8 lens on adapter, set to f/8, you will have so much depth of field that off axis effect won't be noticed. I suspect that the #1 issue with specific adapters will be the quality of electronic pass-through. German/Swiss Novoflex air and Chinese air are identical optical elements.
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Erik Kaffehr
 

tad1973

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #5 on: August 14, 2015, 04:19:31 pm »

Thanks everyone for the feedback. I appreciate it. One thing I neglected to include was that I would shoot with aperture mode using manual focus. Erik, I assume that would negate the impact of infinity focus problems. Is that true? Also, would focus peaking assist in this area - I haven't used that feature, but am aware it exists with the camera.
Thanks again!
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eronald

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #6 on: August 14, 2015, 04:50:17 pm »

I think the only real potential optical issues are the adapter moving during use, axial skew and flare.

symmetric primes eg. Leica need very precise tolerances viz. skew but telecentric lenses eg. Canon probably care less. However, skew is still a very real factor. Of course, I could imagine that if the tolerances of the adapter and lens add up the wrong way you could also have infinity focus issues.

This is getting ridiculous - people who don't do engineering as a job *will* face issues when they start fitting random-sourced elements together - you can do it and try, if it works you're lucky and happy, if it *needs* to work perfectly, then you need to ask a pro dealer who knows what combinations are known to work, or take the baby to a pro repair shop and ask them for advice.

Edmund

« Last Edit: August 14, 2015, 04:53:21 pm by eronald »
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Slobodan Blagojevic

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #7 on: August 14, 2015, 05:00:55 pm »

Hello,
I'm am seriously considering the purchase of a Sony a7Rii camera to use with a Metabones IV adapter along with my Canon L series glass..

Worth noting there is a newer version of the IV adapter:

"Enhancement on new MARK IV (MB_EF-E-BT4) vs. old MARK IV (MB_EF-E-BM4):
The inner hole is painted with flocking material coating. This can further reduce the internal reflection. "

http://www.metabones.com/products/details/MB-EF-E-BT4

telyt

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #8 on: August 14, 2015, 10:12:36 pm »

Thanks everyone for the feedback. I appreciate it. One thing I neglected to include was that I would shoot with aperture mode using manual focus. Erik, I assume that would negate the impact of infinity focus problems. Is that true? Also, would focus peaking assist in this area - I haven't used that feature, but am aware it exists with the camera.
Thanks again!

I use the a7II, not the a7rII, but it has focus peaking which works with adapted lenses.  For most precise focus I find magnified focussing to be more discriminating.
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eronald

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #9 on: August 15, 2015, 12:49:34 am »


In 3 months or so, all the usage patterns will be well known, there will be compatibility lists etc. It doesn't pay to be a first adopter, you just end up being a tester.  If you're technical and enjoy experimentation, that's different.

Edmund
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David Eichler

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #10 on: August 16, 2015, 01:45:52 am »

The only issue might be slightly off-axis flanges, as with any adapter. This can make a difference for some types of photography, but most people won't be shooting subjects where small manufacturing problems with adapters make a difference. Mount a 21mm f/2.8 lens on adapter, set to f/8, you will have so much depth of field that off axis effect won't be noticed. I suspect that the #1 issue with specific adapters will be the quality of electronic pass-through. German/Swiss Novoflex air and Chinese air are identical optical elements.

I disagree with this somewhat. No lens is perfectly aligned and some manufacturers' tolerances can allow for some fairly significant variations, which I have found to be the case with many Canon lenses. Therefore, imperfect alignment of the lens itself, combined with imperfect alignment of the adapter, could, I believe, result in pretty significant overall deviation from ideal alignment. I before selecting an adapter, I think I would suggest finding a Canon lens, or even several, that seems to be well aligned when used on a Canon body, and then use that lens to help select an adapter. You may have to try a number of lenses and adapters to find good ones.

I have never used the Metabones adapters, so I don't have any sense of how tight their tolerances are. Nevertheless, I note that a number of very capable professional photographers are using the Metabones adapters, with Canon lenses among others, very successfully.
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eronald

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Re: Canon Conversion to Sony a7Rii - Help Please
« Reply #11 on: August 16, 2015, 03:10:48 pm »

I disagree with this somewhat. No lens is perfectly aligned and some manufacturers' tolerances can allow for some fairly significant variations, which I have found to be the case with many Canon lenses. Therefore, imperfect alignment of the lens itself, combined with imperfect alignment of the adapter, could, I believe, result in pretty significant overall deviation from ideal alignment. I before selecting an adapter, I think I would suggest finding a Canon lens, or even several, that seems to be well aligned when used on a Canon body, and then use that lens to help select an adapter. You may have to try a number of lenses and adapters to find good ones.

I have never used the Metabones adapters, so I don't have any sense of how tight their tolerances are. Nevertheless, I note that a number of very capable professional photographers are using the Metabones adapters, with Canon lenses among others, very successfully.

I think the rule is going to be "match the adapter to the lens".

Edmund
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