JML 21mm f/3.5 Lens---Mounting Techniques

Craig Gerard · Post by **Craig Gerard** » Thu Jun 03, 2010 7:23 pm

Bob^3,

There are still some JML 21mm/f3.5 listed on the Alltronics website.

http://www.alltronics.com/cgi-bin/categ ... tem=92L031

Craig

Bob^3 · Post by **Bob^3** » Thu Jun 03, 2010 7:42 pm

Ah, so he does have more parts at $10, but shipping went up to $8.50...for some reason he is just no longer selling them on eBay.

Thanks, Craig.

OzRay · Post by **OzRay** » Thu Jun 03, 2010 10:08 pm

You think $8.50 is bad? I just went through the order process and checked out what shipping would cost to Australia - $35.16 USPS, $93.55 UPS!!!!!

Cheers

Ray

bklein · Post by **bklein** » Thu Jun 03, 2010 10:17 pm

Tell them to send Priority Mail International in a flat rate box.
$13.45 up to 4 lbs. The box is only 1 5/8" thick but should be fine.

Barry

Craig Gerard · Post by **Craig Gerard** » Thu Jun 03, 2010 11:34 pm

Ray,

Contact them and ask re- shipping to Australia.

Their website is automated; but human intervention on their part should bring the shipping cost down considerably; but this may initially require an enquiry on your part.

Craig

OzRay · Post by **OzRay** » Thu Jun 03, 2010 11:44 pm

Thanks all. That's worth a try.

Cheers

Ray

OzRay · Post by **OzRay** » Fri Jun 04, 2010 1:49 pm

I asked them and this is their reply:

sorry sold out

Looks like they aren't all that interested.

Cheers

Ray

Craig Gerard · Post by **Craig Gerard** » Sat Jun 05, 2010 12:35 am

Looks like that's the end of the batch.

Alltronics have now removed the JML 21mm/f3.5 from their website.

Craig

kds315* · Post by kds315* » Sat Jun 05, 2010 2:40 am

A few days ago when I ordered mine I was told that they have 30 left. So I wonder where those have gone to...

dmillard · Post by **dmillard** » Thu Jun 10, 2010 7:53 am

I took advantage of the flange by mounting the lens with two nitrile rubber O-rings (ID=15/16", OD=1 1/8", Thickness=3/32") in a 39mm body cap in which I had cut the appropriately sized hole. The body cap fits on my 39mm extension tubes. The O-rings secure the lens firmly, but still allow quick and easy interchangeability if I wish to compare the performance of different copies of this lens.

David

Craig Gerard · Post by **Craig Gerard** » Fri Jun 11, 2010 9:10 pm

David,

That's an interesting method. I measure the flange at 8/32". So, you could do this with any type of close-fitting (JML barrel diameter) step ring or adapter....No wobble?

Craig

dmillard · Post by **dmillard** » Sat Jun 12, 2010 4:21 am

Craig Gerard wrote:David,

That's an interesting method. I measure the flange at 8/32". So, you could do this with any type of close-fitting (JML barrel diameter) step ring or adapter....No wobble?

Craig

Hello Craig,

No wobble at all, due to the compression from the rubber rings. I also tried a larger set of rings (ID=1", OD=1 1/4", Thickness=1/8"). They didn't sit as well in the recessed flange because of the thickness of the 39mm body cap, but would probably work well with a thinner intermediate adapter or step ring.

David

PanoGuy · Post by **PanoGuy** » Tue Jun 15, 2010 6:37 pm

One more successful mounting:

OM mount to 49mm reversal ring
49mm to 46mm step-up ring
30.5mm to 46mm step-up ring
JML lens with 2-3 layers of tape around it

This allows it to be mounted directly to the front of an OM bellows. Press-fitting the lens into place seems to work well (thanks Bob).

The setup can also be mounted directly to the front of my camera (Olympus E-300) with only the addition of a 4/3-OM adapter. This gives a somewhat lower magnification, but leaves only a few mm of clearance for the mirror and I don't have a good method of focusing.

Magnification with this setup was calculated from these mm scale images (uncropped):

Mounted directly to camera: 1.7x
Minimum bellows extension: 3.5x
Maximum bellows extension: 11.5x

kds315* · Post by kds315* » Mon Jun 21, 2010 1:59 pm

As promised, here how I have it mounted it. Design has been done in collaboration with a good friend in Holland who also had that professionally made. It is a holder with three set screws which grip onto that groove on the lens, holding it very tightly. The rear mount is M42x1.0 so fits about anything. The helicoid is a double extra long helicoid I had custom made for some Nikon friends with rear Nikon mount, front M42 mount and that extends to about 90mm. That solution is very sturdy and can also be used in the field, but I guess not many will do stacking outside. [It took a bit longer to get it done this way, that must be the German in me and the engineer

]

Bob^3 · Post by **Bob^3** » Mon Jun 21, 2010 3:37 pm

Klaus, that piece is truly a thing of beauty! And I think by far the most elegant and functional design so far. I’m planning something similar as soon as some thick-walled Al tubing arrives. I have some limited machining capability in my home workshop to open the ID a few tenths of a millimeter. Then I’ll drill and tap the three screw holes. I plan to use small thumb screws to hold the lens in place, to allow faster swap of my JML lenses. But mine won’t be turned out of a single piece and nicely black anodized(?) like yours. And it won’t have the custom-made helicoid focus movement, which is just over the top.

I say, who needs one of those boring Canon MP-E things, anyway!?

Bob