Author Topic: EOS to m4/3 adapter with Aperture controle (Read 1551 times)

panzerfaustnl · « **on:** December 27, 2011, 04:53:45 PM »

I have seen an adapter for the m4/3, so you can use CANON EOS EF/(S?) lenses on an micro 4/3 camera. You can buy it from Amazon.

http://www.amazon.co.uk/Canon-Ring-adjustable-Aperture-Panasonic/dp/B006F8WGLW/ref=sr_1_5?s=electronics&ie=UTF8&qid=1325033161&sr=1-5

picture:
http://ecx.images-amazon.com/images/I/31g33h%2BnIqL.jpg

as you can see without AF confirmation, but I have not found one adapter who has AF confirmation for the m4/3

voyager · « **Reply #1 on:** December 27, 2011, 07:09:04 PM »

I don't think that's available.

panzerfaustnl · « **Reply #2 on:** December 28, 2011, 01:22:58 AM »

I looked just a few moments ago and it is in stock.

voyager · « **Reply #3 on:** December 28, 2011, 03:26:04 PM »

I meant one with AF confirmation.

Em5 Pete · « **Reply #4 on:** December 28, 2011, 05:51:48 PM »

That's better than a $200.00 one I saw about a year ago....

panzerfaustnl · « **Reply #5 on:** December 28, 2011, 06:33:14 PM »

I am very curious if somebody has some experience with it. because the aperture ring makes it thicker.

Jason C · « **Reply #6 on:** December 28, 2011, 08:56:25 PM »

Now I am no engineer, but a lens diaphragm has been engineered to be were it is located within the glass elements inside of the lens. I do not see how Moving a diaphragm to outside of the rear element of the lens would work well at all.

Jason C

adash · « **Reply #7 on:** January 01, 2012, 01:04:03 AM »

Quote

Now I am no engineer, but a lens diaphragm has been engineered to be were it is located within the glass elements inside of the lens. I do not see how Moving a diaphragm to outside of the rear element of the lens would work well at all.

+1! The diaphragm position is very important for aberration and distortion control.

Em5 Pete · « **Reply #8 on:** January 02, 2012, 03:47:53 PM »

I think hh2r bought the more expensive one...
But, I haven't seen a post lately.....

panzerfaustnl · « **Reply #9 on:** January 02, 2012, 04:00:20 PM »

I don't know, aperture is to controle the amount of light reaching the film/sensor, so why is it so important where it is.

Em5 Pete · « **Reply #10 on:** January 02, 2012, 04:33:03 PM »

I found an interesting Wikipedia article
http://en.wikipedia.org/wiki/Entrance_pupil

a snipped part

well more the CENTER of the Optics... but it mention the IRIS placement Per say.

In an optical system, the entrance pupil is the optical image of the physical aperture stop, as 'seen' through the front of the lens system. The corresponding image of the aperture as seen through the back of the lens system is called the exit pupil. If there is no lens in front of the aperture (as in a pinhole camera), the entrance pupil's location and size are identical to those of the aperture. Optical elements in front of the aperture will produce a magnified or minified image that is displaced from the location of the physical aperture. The entrance pupil is usually a virtual image: it lies behind the first optical surface of the system.

The geometric location of the entrance pupil is the vertex of the camera's angle of view[1] and consequently its center of perspective, perspective point, view point, projection centre[2] or no-parallax point.[3] This point is important in panoramic photography, because the camera must be rotated around it in order to avoid parallax errors in the final, stitched panorama.[4][5] Depending on the lens design, the entrance pupil location on the optical axis may be behind, within or in front of the lens system; and even at infinite distance from the lens in the case of telecentric systems.

Now, it not discuss Element Corrections... But, the edges of these natural glass lens elements have the most errors in transmission of light, and the IRIS, as it is stopped, blocks those errors from reaching the sensor. Better Lenses have artificial lenses -- man made -- (ASPH, ED, etc) to correct these errors, so even wide open, they preform well.

EDIT & 2nd thoughts
I think is not about the IRIS at all...
But about how the image is projected, and centered.... opps

I'll keep in anyway... because the IRIS must be centered along with the optical center of the lens....
as far as where it must go....? It has always gone between the two major blocks of elements... which may be related to the optical center of lens blocks......

Gruu · « **Reply #11 on:** January 05, 2012, 09:46:35 PM »

Some new recent insight into this really cool adapter. I recently picked up a Yashica 135mm f2.8 lens and was researching how best to adapt it to my E-P1. The lens is a Contax/Yashica mount (C/Y). I could have bought an adapter to go straight from this lens to m4/3, but also wanted to take advantage of a bunch of old EOS lenses that my mom has laying around. So, I picked up the Kipon EOS to m4/3 adapter (with aperture control, of course) and then grabbed a thin little C/Y to EOS adapter which pretty much stays on the Yashica at all times. Here is a previous discussion from a while back about different EOS to m4/3 adapters http://e-p1.net/accessories/canon-ef-lens-adapter-to-m-43-with-aperture!!/msg45816/#msg45816 , but I went for the unmentioned Pro-Optic version (Adorama's rebranded Kipon if I'm not mistaken, mine does have "Kipon" on the side) because it was much less expensive($65 then, closer to $89 now) than all the other options. Oh, there is a "EzPhoto" version in the $65 range now, so good news! Okay, so if you're still with me, here's the cool part. Now I can choose to either use the 6-blade aperture of the Yashica lens, or I can use the 14-blade aperture of the adapter. Talk about a shape change! Here are examples of each in action...

Details

Now, certainly this shows a lot and yet not much. First, I need to get my lens cleaned.

Second, I can "adapt" a different aperture to lots of lenses! Well, any lens that can adapt to the EOS system anyway. And most likely little effect on a lens that already has a similar aperture. One part I don't know, and don't understand enough to predict, is whether or not this will alter how a blurred background will appear. My lens is apparently known to make muddy out of focus backgrounds, so I am curious. Perhaps someone can predict this for me, but I'll give it a test shot in the weeks to come and see if I can come up with anything conclusive. Also, certainly the two different apertures are in different locations within the system, so does that simply change the focal range wherein the blade edges become visible? The two photos do have a difference in distortion, but this is way out of my league, so again I'll defer to a pro. Anyway, thanks for reading, I do look forward to any thoughts that may spark from this. Oh, and please share these sorts of discoveries if you ever find them... this sort of thing rarely occurs to me and I'm all for scratching every ounce of effect out of my camera when the shot calls for it. Cheers!

tamoio · « **Reply #12 on:** January 17, 2012, 01:32:42 PM »

If you are seriously married to your EF glass this is the unit:

http://store.redrockmicro.com/livelensmft

Its been in circulation for several months and everyone I've chatted with that used one says it works.

adash · « **Reply #13 on:** January 17, 2012, 01:51:16 PM »

Quote from: tamoio on January 17, 2012, 01:32:42 PM

If you are seriously married to your EF glass this is the unit:

http://store.redrockmicro.com/livelensmft

Its been in circulation for several months and everyone I've chatted with that used one says it works.

That isn't exactly surprising, as EOS protocol was decoded a while ago. I whish to think they could have spared the hump with the controller, but whatdoyawant for $540......

panzerfaustnl · « **Reply #14 on:** January 17, 2012, 02:18:52 PM »

I use analog and digital EOS camera's so yes I am using my EOS lenses and I want to use them with my PL1 to.

overflow · « **Reply #15 on:** January 17, 2012, 03:00:52 PM »

The main thing I would be concerned about with an improperly placed aperture is vignetting. Somewhere around the middle of the second aperture's range its going to be blocking a lot of the light going to the corners of the image while not blocking any of the light that's going to the center.

Similarly the aberrations around the edges are going to be cut off strangely as well, so stopping down the second aperture will still increase the contrast, depth of field and dim the image as expected. But, I would guess that the aberrations would get 'lop-sided' appearing somewhat like coma. You can kind of see this in the above image... In effect the aperture is correcting for the outter-most part of the aberrations, but not the inside.

EOS to m4/3 adapter with Aperture controle