I found a seller on ebay who sells reversing rings that will work. I've ordered one and it's supposed to have shipped from China last week. I'll post my experience here once I get it.
This is what I ordered: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7519529506
I have ordered and received both the 52mm and 58mm Canon EOS reverse lens adapters from "jinfinance" on ebay. Seller ships with a signature required for delivery. They work great. I have been having fun using them. I would post a picture here that I have taken with them but don't know how. Just started learning about "macro" and photography in general.
Try this link MacroPic
Rob:
Thanks for the positive feedback for the ebay seller. I was a little apprehensive about ordering from him.
As for posting pictures, you can upload them to a free image host and link them here. I usually use www.photobucket.com or www.photodump.com for hosting. Or, if you want, email them to me and I'll post them.
Thanks to Tom for initiating this thread and for the nice photos.
I will share my experience for your feedback, and possible improvements.
I have not tried the solo - reversed prime for macro yet, but did some reversed lens on lens earlier. (I used the EF 50/1.4 reversed on EF 100/2.8 - using a 58mm to 58mm adapter).
Since focussing gets much difficult at that magnification, I chose these two - as there might be minimal loss of light due to mismatch of size of front element of each, and I could utilize the high aperture of the 50/1.4. ...I also hoped that the distortion would be minimum since both these lenses are pretty well corrected optically.
This was a very handy set up - for which I didn't need to carry any extra lens modified only for macro - while doing my field trips, with the 100 macro most times on my camera, and whenever I would get a chance - I would put the 50 reversed with the help of the adapter.
One prime concern was damaging the rear element of the 50/1.4 by exposing or accidentally touching the plant structures. .... So I cut a hole on the rear cap of the lens - and put a good quality filter glass (49mm or 52mm - I forgot) inside the rearcap - which came in pretty handy. Specially for situations where I had to quickly shoot a higher magnification near ground shot - or where some prickly things were dangerously placed near the exposed front end.
tintinb wrote:
Thanks to Tom for initiating this thread and for the nice photos.
I will share my experience for your feedback, and possible improvements.
I have not tried the solo - reversed prime for macro yet, but did some reversed lens on lens earlier. (I used the EF 50/1.4 reversed on EF 100/2.8 - using a 58mm to 58mm adapter).
Since focussing gets much difficult at that magnification, I chose these two - as there might be minimal loss of light due to mismatch of size of front element of each, and I could utilize the high aperture of the 50/1.4. ...I also hoped that the distortion would be minimum since both these lenses are pretty well corrected optically.
This was a very handy set up - for which I didn't need to carry any extra lens modified only for macro - while doing my field trips, with the 100 macro most times on my camera, and whenever I would get a chance - I would put the 50 reversed with the help of the adapter.
One prime concern was damaging the rear element of the 50/1.4 by exposing or accidentally touching the plant structures. .... So I cut a hole on the rear cap of the lens - and put a good quality filter glass (49mm or 52mm - I forgot) inside the rearcap - which came in pretty handy. Specially for situations where I had to quickly shoot a higher magnification near ground shot - or where some prickly things were dangerously placed near the exposed front end.
Sure, probably it will be easier to take some shots again now than trying to fish out the ones taken about 2 years back when I was experimenting with new ideas.
One shot I distinctly remember (you can try yourself) -
the red tips at the end of usual comb (with some unintended micro dirt, yickes!!) with only a bunch focussed and most out of focus (in front of or behind the "plane of focus" ... err, forgot the scientific term). I might try it again if somebody does not come up with the same.
I was curios how the images looked, but now that you mention it, a shot of the set-up would be nice to see as well. I have both of these lenses and I am thinking of buying a 58mm to 58mm adapter.
Shahn
I just received my reverse lens adapter. I tried to take a few pictures with the reversed 50mm and it'snot as easyas it seems. But, it is a lot of fun ! Now to find me some insects
I have an FD 50mm f/1.8 in front of me and I am trying to lock the lever so that I can control the f stops. However, it wont go all the way and if I move it as far as I can, when I turn the aperture ring the opening on the lens stays the same.
What could the problem be? Do I need to press something else to make the lever go the whole way?
Alex:
I have the same lens. In order to get the manual aperture to work, I cut a hole in the rear lens cap and with the lens cap ON, it's now possible to change the aperture manually. This way the lens thinks it's on the camera.
Only I dont have the rear lens cap. I picked up this lens from my local photography club, it was on an old canon body (T90?) and no lens caps, just a dirty skylight filter, and among a lot of other old lenses and cameras that members have left there over the years, scrapyard style.
What does the rear lens cap move on the lens? I need to simulate this...
It moves a tiny metal lever (?) along the circumference of the lens. Someone had posted a picture of this on this forum, but that thread has been archived and all the pictures are gone.
EDIT: Forgot to mention, you buy a rear lens cap pretty cheap on ebay. I got one for $3.00 inlcluding shipping... (doesnt fit exactly as it should, but you might be able to get a good one)
Hmm I can see 2 very small metal bits along the circumference. If you hold the red spot at 12 o'clock, one if just to the right and the other one is at 4 o'clock. Is that them? Maybe pressing them down and holding them with something else would work? Do they make the bigger lever go all the way once they are pressed down or is the bigger lever ok just to the point it goes now?
EDIT: Anyway, I went off and shot wide open. Depth of field is tiny but useable for something flat like the coin I tested with. I got about the same magnification I get with the canon 100mm 2.8 macro usm. Not very impressed in that sense, I thought I'd get more.
Since I had the 'adapter' I tried with the 50mm f/1.8mkII. I understand being a newer lens that sets its aperture electronically from the body, it had to stay wide open too. I got similar results, but slightly more working distance. Although maybe it was less magnification due to that extra distance, I didnt compare exactly.
Then I stuck the 3 kenko extension tubes. I understand that extension tubes give you more magnification on a wider lens(?), ie more on the 50mm than on my 100mm macro. I did get a lot of magnification, but by that time the built-in flash was not going over the whole setup and I didnt get any decent shots.
siddharth wrote:
It moves a tiny metal lever (?) along the circumference of the lens. Someone had posted a picture of this on this forum, but that thread has been archived and all the pictures are gone.
EDIT: Forgot to mention, you buy a rear lens cap pretty cheap on ebay. I got one for $3.00 inlcluding shipping... (doesnt fit exactly as it should, but you might be able to get a good one)
I'm assuming these are FD lenses you're using. I just started playing with a few of my old ones and you have to do two things:
1) Lock the lever in the up position like a few people have already mentioned. On my 55mm and 28mm, basically I just move this lever all the way up and it will automatically lock in place (it will give some resistance at some point, so push gently past it and the lever will just lock in place). On my 50mm 1.8, there's actually a small switch, so I just toggle it to "L" with the lever all the way and it locks up fine.
2) My FD lenses have a silver metal lens mount that you would twist to lock the lens in place on the camera body (you manually stop down the lens when the mount is locked in place). So there are a couple ways of doing this...either get a spare lens cap, drill a hole through the face, and just put that thing on the lens like normal. OR, if you look closely just underneath the red dot, there should be some kind of latch, so just press down on that to unlock the lens mount. Either method will work fine (not sure how well the spare lens cap acts as a hood against flaring, but it's probably better than nothing).
Hopefully this isn't too cryptic...I can take a few shots to clear things up, but it's 2am right now.
Tom: thanks for all of the info. I've built the reverse camera attachment, and for all of you who are wary: it's easy. Shooting with it, however, is not easy. It's going to take some practice. I've never been so frustrated with a small gust of wind before
I just made my reverse lens mount with a 58mm uv filter. I attached my EF-S 18-55mm to take a few test shots. The DOF is so tiny with the EF-S. I'm bidding on a FD 50mm right now. will I need a 58mm F - 52mm M step-down ring for the FD lens?
Tom,
Need some help, I finally received my Canon FD 28mm f2.8 for the reverse lens setup, but I can't get that aperture lever to lock, it only goes halfway and I don't want to push it too hard (trust me I am pushing it real hard already) don't want to break it, but is there another button that I must push somewhere that will unlock it and allow me to do so??
Also, please excuse me for sounding a little ignorant, but I never used the old MF lenses, so will I be able to change the aperture when I want with the aperture ring, or do I have to lock it in before hand??
when I was experimenting with new ideas. 
I picked up this lens from my local photography club, it was on an old canon body (T90?) and no lens caps, just a dirty skylight filter, and among a lot of other old lenses and cameras that members have left there over the years, scrapyard style.