John Lindroth

Hi Alex - most definitely! I really enjoy the lens. Not sure it's worth the prices asked on fleabay, but at $23 it's an amazing addition to my toolset. Here are some test shots, most at f2.3, but it's difficult to tell if it's stopped down because the aperture is always a circle! I've also used it for some headshots, and I really like the results (but don't want to add those photos here). I haven't used the lens yet on a full frame camera. All these photos, except the butterfly, were taken on a Fujifilm X-E1. Butterfly was with a Sigma SD9.

I never measured to see if the lens is perfectly aligned, but the washers I used were all perfectly flat, so for a first attempt, I'm satisfied. I'll try to shoot some test images to see if the edges are unevenly out of focus, but my thoughts were to use this for portraits, so there won't be any issues with edges, as I would want them out of focus. From my first test shots (taken before I had this new setup), I was impressed by how sharp the images were. And the iris has 16 blades, and they appear circular, I can't see any pattern to the background all the way down to f16: DSCF3943.JPG f2.3 DSCF3944.JPG f2.8 DSCF3945.JPG f4 DSCF3946.JPG f 5.6 DSCF3947.JPG f 8 DSCF3948.JPG f11 DSCF3949.JPG f16 Now to find some models...

I wanted to add an update, with many thanks to the folks who have replied to my initial post/question. I've got the lens mounted in an M42 mountable, focusable piece. I purchased an M52 to M42 Helicoid Focus Macro converter with 17-31mm range. Adding that onto the 45.46mm flange distance for the M42 put the lens right in range for the 60.3mm for the Baltar (thanks Alex!). My first thought was to find a machinist who could create an adapter between the two. This still might happen, but cost for a prototype was about $125. Very well within range for the actual value of the lens, but I wasn't sure if I wanted to spend that much starting off. So I searched and found an interesting compound called Apoxie Sculpt - an epoxy resin that stays in a sculptable dough for about 3 hours. Through some testing, I made sure that a good machine oil on a screw would not adhere to the resin once it hardened. With lots of measurement and testing, I created a piece to hold the lens at a distance that would put the lens a little past infinity (so I knew I could get to infinity on the camera) and molded the resin into place. It focuses to about 24" close focus. As of this morning, I have a perfectly usable Baltar 75mm lens, and I can mount it on all three of my interchangeable lens cameras (Fujifilm X-E1, Canon 5DMkII, Sigma SD9). Thanks to everyone for your help. Now comes the fun part of testing... -John

I'm still waiting for the helicoid macro adapter to arrive, but I've contacted a couple local machine shops to see what kind of quotes I can get. Sadly I have no experience with CAD. I've considered 3D printing as an option, but no idea how to make that happen. I'll check around with some stuff out there as well.

Thanks Alex. I'm doing some testing now, to see if I can make something unusual work. I've purchased some ApoxySculpt clay, and an M52-M42 17mm-31mm Helicoid Macro adapter. I'm planning to use the clay to create a lip inside the M52 that will hold the lens in place (coating it with machine oil, so it doesn't stick). I've done some testing, and the material is super strong once it's hardened, and I've used it in some test cases where I think it will work here too. I really don't want to ruin the lens, and stick it forever in the adapter, so I'm moving forward very carefully...

Thanks Alex. I've been away on vacation, and I just saw your reply. I'll do a little testing myself, but this should make it simple to determine the right adapter. Does anybody know about the screw mount on the back of the lens? M42 is too large, M39 seems too small. Perhaps an "M40"??? I really want to keep the lens as intact as possible.

Thanks Mark. I think the second link might have the key to making this work. They have mounted the lens in an adjustable macro adjustment ring, basically adding both the mount adapter and focusing in one piece. Looks a lot like this one: http://www.aliexpress.com/store/product/Adjustable-Focusing-Helicoid-Macro-Tube-Adapter-17mm-to-31mm-Suit-For-M42-to-M42-Lens/701997_1552455732.html I won't have actual possession of the lens until FedEx delivers it this week, and I'll do a little testing for focus distances, but I think you've turned me on to something perfect. They certainly do list for high prices. I'm hoping the glass is fairly clean in this one. -John

Hi all. This is my first post as a member. I'm thinking that this is the place to get some answers to a new project. I recently purchased a Baltar 75mm f2.3 lens. I'm attaching a photo, that will show you the mount. I got it at a deeply discounted price, so I thought that there are two possible options for it: 1. re-sell 2. find a way to convert/adapt the lens to be used on my Canon 5DMkII *** this is preferred, I'm a still photographer, but love old lenses I have been searching online for companies that work with old lenses, and most will clean lenses, but do not offer conversion service. But I'm assuming that I'm looking in the wrong places. So here are my questions so far, for which I have no answers: 1. what lens mount does this lens have? 2.Is there an adapter to EOS, or to another mount (M42?) that could be adapted to fit? 3. Doe this lens have the ability to focus, or is it in the camera mount? 4. I have seen this lens mounted into what looks like a Nikon 50mm f1.8 deconstructed lens. This might be interesting, but I can't find the person who is doing it, or any technical info on how to do the conversion. Any other information about would also be greatly appreciated. Thanks, -John