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Garry Torrance

Canon EF lenses on Panasonic AF101?

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I'm considering buying an AF101 but my lenses are all Canon EF-mount (I have a 7D at the moment). I've heard that there is (or will be) an adapter that will allow the aperture of an EF-mount lens to be controlled via the iris wheel of the AF101, but I can't find an example of this adapter for sale anywhere. Does anyone own one of these or know where I can buy one? And for what kind of price?

 

Thanks in advance,

Garry

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Some info for those who are not already in the know:

 

There is a considerably cheaper (£90/$135) Canon EF to Micro 4/3 adapter available from China:

 

http://cgi.ebay.co.uk/Canon-EOS-EF-Micro-4-3-Adapter-w-Build-Aperture-/350425329571?pt=UK_Photography_DigitalCamBatt_RL&hash=item5196fa2fa3#ht_3213wt_1058

 

It doesn't support electronic control from the AF100/101 but it does have a manual aperture ring on the adapter. However, it does not take EF-S lenses: this is a pain since EF-S lenses are optimised for APS-C (which is much closer to the size of the AF100/101 sensor).

 

I've emailed Birger Engineering to ask if their adapter will support EF-S lenses (unlikely I guess) and also if it will support full electronic control of Zeiss ZE lenses. I'll post their reply.

______________________________________________________________________

Garry Torrance

DP • Lighting Cameraman

+44 (0) 7900953590

www.garrytorrance.co.uk

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Interesting approach on the Chinese adaptor.

 

I'm not an optical engineer - can you... just do that? Throw another variable aperture into the optical path? Aren't there downsides to that? It looks to have a multi-bladed iris, so the artifacts should be round at least, but it makes me wonder what the bokeh will be like.

 

P

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I'm not an optical engineer - can you... just do that? Throw another variable aperture into the optical path?

 

 

I would have thought that placing another iris after the rear element of the lens would lead to vignetting at small apertures, but I'm not an engineer either.

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The manufacturer does state (in poor english) that vignetting will occur if the aperture is brought down past a certain size.

 

Another big concern that's sprung to mind: if the 'front' aperture defaults to and stays wide-open, does that mean the depth-of-field will always be at the shallowest, regardless of the size of the adapter's aperture?

 

I've emailed a lens-repair guy I know (he used to be a lens engineer for Canon), I'll post any answers he may be able to provide.

_________________________________________________________________________________________________

Garry Torrance

DP • Lighting Cameraman

+44 (0) 7900953590

www.garrytorrance.co.uk

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And another one: the aperture ring goes from 1 to 6, so in order to know what exactly you're working with you'd have to measure the size of the aperture at each setting then calculate focal length/aperture diameter for each lens at each setting to work out the actual f-stop..

 

I guess this adapter is most likely a piece of poop.. but interesting nonetheless..

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For all of the reasons mentioned above as well as others, this is definitely not the way to do this. I would not want to use this Chinese device.

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Probably no-one in their right mind is considering buying this particular adapter, especially after the above comments (I'm certainly not), but out of interest here is the response from that email anyway:

 

"There would be many problems with the aperture behind the front lens, one in particular is the focal plane: by shifting the access area, you will move the f stop because you are moving the amount of light coming into the lens , if your not worried about F stop as the aperture seems manual, how is the aperture controlled in the EF lens? .. remember its the camera that selects your aperture in an EOS camera, not the lens.

I can also suspect lots of ghosting, and reflection bounce: these apertures in EF cameras are all at different measurements within the lens. Not every aperture is in the same place, its not just some guy throwing in an aperture and saying 'right that's it', there is a whole length of mathematical calculations to measure where these apertures are placed in a lens: a 24mm will be at an entirely different focal plane aperture fixing than say a 100mm, and that's just the focal fixing if you look at a zoom lens say 18-55mm F/2.8 the aperture at 18mm when you zoom out to 55mm will close slightly because f2.8 at 18mm is not the same pitch at 55mm this is all mathematical calculations [...] I would also advise to look at the English in this products description, if it were a fully justifiable product they would have spent a few quid on Technical Authorship"

 

Those comments were from Eddie Houston (aka The Lens Doctor), here is a write-up about him and his services, also quite interesting (not least his rock'n'roll background):

 

http://www.dslrnewsshooter.com/2010/12/27/the-lens-doctor-de-clicking-in-the-uk/

 

Lastly, I wrote a four-letter word beginning with 's' in my previous post and it somehow magically changed to 'poop' when it appeared in the thread: what's that all about? Does this forum have language clean-up software? I don't use words like 'poop', in Scotland we (notoriously) prefer real profanity :lol:

 

_________________________________________________________________________________________________

Garry Torrance

DP • Lighting Cameraman

+44 (0) 7900953590

www.garrytorrance.co.uk

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I'm not actually that worried about knowing what the F number is. I usually find myself watching a waveform monitor and closing down until it stops clobbering the end stops, at which point it is right, whatever the number is.

 

But otherwise yes. Perhaps not the way to go.

 

 

in Scotland we (notoriously) prefer real profanity

Oh, I think that's something we could do with a lot more of down south as well. Perhaps some sort of cultural exchange is in order.

However there are Americans here and while they have no problem with violence in movies or the NRA's Arm A Toddler campaign, they do have this strangely puritanical attitude to strong language.

It is very strange.

P

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I see your point about the f-stop, personally (and when time allows) I like to decide what f-stop I want for the d.o.f. I want, then set the ISO/lights/ND as required to get the right exposure.

 

I was tempted to type in all the swearwords I know into this post just to see how they will be 'edited', but I guess I'd better keep it professional :D

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I said I would update this thread with any further info I got from Birger Engineering reagrding their adapter: I've been assured that it will work with both EF-mount and EF-S mount lenses made by Canon, Zeiss, Sigma and Tokina (I didn't ask about any others). They couldn't say for certain that AF functions will work 100% efficiently with motors in lenses made by Sigma or other manufacturers other than Canon (not that many of us will want auto-focus anyway: surely iris control is the main thing), but they will fit on the mount and allow iris-control from the camera.

______________________________________________________________________

Garry Torrance

DP • Lighting Cameraman

+44 (0) 7900953590

www.garrytorrance.co.uk

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Hi,

 

I'm looking into lenses for the Panasonic AF. While the canon EF lenses and their various adaptors have been discussed in this thread, I would be interested to know if there are any other experiences with other lens systems, preferably lenses with manually adjustable iris. Nikon also have electronic iris. Olympus, Voigtlander (not heard of them), Panasonic and Leica are possibilities. Anyone got any experience with these and particularly do these lenses have manually adjustable iris?

 

Thanks and Regards,

 

Matt Skinner,

Dop,Ireland.

http://www.iol.ie/~mattskinner

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You could go older. I wouldn't ever trade my old Nikon stills lenses for, well anything... Also substantially cheaper to buy and will save you the diffusion filter to take the HD edge off.

When i got my Letus (yes that letus) long ago, I went with Nikons, and even now when working with cameras which record video like the GH1/2 for fun when they came out, the Nikons really held their own.

I have a 50mm F1.4, 75 mm F2.8 135 mm F2.8 35mm F2 and 15mm F2.8 (i think, been awhile since I pulled that one out). Food for thought, and saves a few hundred (which is a few nikon used lenses) on the adapter price. Depends what you want, though. It will be a bit "softer," then a DSLR optimized lens, but not out of focus in that sense.

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