Where to place Extension Tubes?

I'm thinking about getting a set of extension tubes and wonder where to place them when using Canon mount lenses via a converter on a Sony E-mount camera. Will they go between the converter and the camera or between the converter and the lens, or is it ok either way? It matters because depending on where they go I will have order either EF-mount tubes or E-mount tubes.

Maybe this will help clarify:

http://faculty.ucr.edu/~chappell/INW/le ... cros.shtml

I know there are other write-ups out there I have seen, but I haven't located them yet. On some Nikon lenses, it is not possible to attach the TC to the lens because the lens' rear element will it the front element of theTC.

Joe

SantaFeJoe wrote:Maybe this will help clarify:

http://faculty.ucr.edu/~chappell/INW/le ... cros.shtml

I know there are other write-ups out there I have seen, but I haven't located them yet. On some Nikon lenses, it is not possible to attach the TC to the lens because the lens' rear element will it the front element of theTC.

Joe

Thanks Joe. I made a mistake, though. I meant to write "adapter" but my fingers created "converter". So, the question is, tubes between adapter and lens or between adapter and camera?

Sorry for the mess.

The only way the extension tubes (assuming they are Canon extension tubes) will work is between the lens and the adapter. The adapter is making the Sony E mount into a Canon EF mount so that Canon lenses can be mounted onto a Sony camera body. This is the way I'm using my Canon extension tubes and it works great. If you haven't bought your adapter yet I'd recommend that you get the Metabones Mark IV adapter. It provides almost the same AF capabilities and speed as Sony lenses have on the Sony a7R2. I have a Sigma 150 mm f/2.8 macro lens with Canon mount that was a first generation lens. The 150 wouldn't work on the Sony a7R that I had with the Metabones Mark III adapter (all my Canon lenses worked). I could not take an image consistently with this combo, as at times the camera would not recognize the lens even if I used the lens in manual focus. Now using the Mark IV adapter with the latest firmware update and the a7R2 the 150 works just as it does on my Canon bodies. The 150 will AF even with 2 extension tubes a 25 mm and 12 mm (no I don't usually use AF with extension tubes - just was testing to see it would work and it did).

Sorry, Jens! It was me who misunderstood the question. You were clear.

Joe

I use Canon tubes and they try to work either side of a 1.4x, but only AF well if placed closest to the camera, if you look at the Exif it seems they pass the data straight through like an extension cord, Seems like they work electrically either way but optically there is an issue, so provided your adapter has no optics you should have no issues.

I have never found any reference to an extension tube being in place in the EXIF. Assuming no optics in your adapter, it is also just extension. I think you could go either way but you know that the Canon tube will just report the lens info straight through so your Sony/adapter combo so it just thinks that just the bare lens is there. Seems to me there's no way this could not work. But I don't know if an E-mount tube will behave the same way. So would suggest a Canon tube. Of course assuming it is a smart adapter that conveys Exif data and if it AF's all the better, lenses like the Canon 300mm f4 AF really well with a Canon tube.

BTW the Canon tube seems quite reliable with it's connections in my experience, but have not always heard that about third party tubes.

ChrisRoss wrote:I use Canon tubes and they try to work either side of a 1.4x, but only AF well if placed closest to the camera, if you look at the Exif it seems they pass the data straight through like an extension cord,  Seems like they work electrically either way but optically there is an issue, so provided your adapter has no optics you should have no issues.

I have never found any reference to an extension tube being in place in the EXIF.  Assuming no optics in your adapter, it is also just extension.  I think you could go either way but you know that the Canon tube will just report the lens info straight through so your Sony/adapter combo so it just thinks that just the bare lens is there.  Seems to me there's no way this could not work.    But I don't know if an E-mount tube will behave the same way.  So would suggest a Canon tube.  Of course assuming it is a smart adapter that conveys Exif data and if it AF's all the better, lenses like the Canon 300mm f4 AF really well with a Canon tube.

BTW the Canon tube seems quite reliable with it's connections in my experience, but have not always heard that about third party tubes.

Thanks Chris.

My question is strictly regarding the optical aspects of such an assembly. AF is not a subject - I am a compulsive MFer - and EXIF is just a convenience, it's absence wouldn't kill the project.

Like you, I think they can go either way. It would be nice to have some confirmation on that, though.I will check the local camera store for a cheap used tube to run some trials and, depending on the results, may order a set of new tubes.

Jens, Gordon's has a third party varairable extension tube, can't speak of the quality but thought of it as a interesting idea that may be the future acessory.

If it's just optics, place it anywhere, if there's no glass in your adapter then it's all extension and wouldn't matter. But I'd still do the Canon tube to get Exif and more reliable connections, you still need them to stop down the diaphragm in the Canon lens unless you also like to shoot wide open.