Disassembly – TTArtisan 50mm F1.2 lens in Fuji X mount

Today I finally found way to safely disassemble new interesting lens – TTArtisan 50mm F1.2 in Fuji X mount. As you know all my lens disassembly articles are self-exploratory process described after numerous investigation steps.

As usual I’m first disassembling, taking pictures, then assembling lens back, testing that everything is fine and there are no quality degradation. Then I’m writing article for you : )

Just to remind that I received this lens sample for review purpose from one of TTArtisan dealers – bestar.foto on Amazon , and including non-affiliated links to their currently listed TTArtisan products . It’s great to have opportunity sometimes receive new lens, and explore its optical and also mechanical potential. I’m highly interested in exploring how to repair lens and also get idea about its durability, engineering level and assembly quality.

TTArtisan 50mm F1.2 – rear area disassembly

Process of rear disassembly is quite trivial, however take into account that it includes opening focusing helicoid, which sometimes hard to put back together and required hand precision skills.

First step is to unscrew three rear mount bolts.

Surprisingly the mount ring is quite light, looks like it’s made of aluminum of some other light metal alloy, probably to keep the lens total weight lower and I like it. However to keep the mount ring connection strong TTArtisan lens engineers are using long and durable bolts, and also applying securing glue.

Of course all inner frame is made of aluminum and all surfaces are machined with high precision and quality, edges are smooth and surfaces are anodized. I’m glad to see helicoid guiders made of brass and secured with two bolts each. At this step first focus lens to infinity and then accurately unscrew all four bolts. Then by slightly moving focus ring forward-backward to avout 1 degree help to loose brass guiders and accurately extract them. I’d highly recommend to memorize each guider exact position and put it back there during assembly, do not mix them.

Helicoid guiders are thick and durable, they should last for long.

Double check that focus ring infinity point remains near vertical central line. Keep the focus ring non rotating during this step, you may also want to add a piece of adhesive tape to secure its position. Then very slowly rotate whole rear frame together with focus ring CW until it disconnects from the lens helicoid core thread.

Mark the position of the brass bolt near the aperture ring edge (make sure aperture value is set to F1.2). You’ll need to catch the helicoid thread at this exact position when assembling lens back.

Outer helicoid ring is made of aluminum, and lens core helicoid thread is anodized, which prolongs the life of focusing mechanics. Level of thread precision is noticeably higher comparing to Mitakon 35mm F0.95 mark II helicoid I used to disassemble many times. Focusing mechanics precision is very well made in this TTArtisan 50mm F1.2 lens sample.

Looks like the rear optics is secured by a single ring inside whole lens core frame and can be only extracted one by one element, which I don’t do today because everything inside is perfectly clean and clear. At htis point I’m assembling everything back in a reverse order to keep using lens during the weekend.

(Update) I was unable to open the front area so took a few days break and tried again with success : )

TTArtisan 50mm F1.2 lens – front area disassembly

Prior to this step I’ve added few drops of acetone at the perimeter of the front naming plate ring, because it sits very tight and there could be extra glue to secure it. Then I’m using very strong 3M adhesive foam, cutting strips and adding them to the edge of M42 extension tube. Finally I’m attaching that with slight pressure to the TTArtisan 50mm F1.2 lens nameplate ring and applying strong initial torque CCW to release it. Then I’m accurately unscrewing the nameplate.

There is nothing holding the front lens module except the nameplate ring I just removed, however it stays in place even if I flip the front down and shake the lens (do not do it!). Use marker to mark radial position of the front lens module – you’ll want to put it exactly same when assembling for proper optical alignment.

At this step screw in the front nameplate to 1 full turn first, then flip the lens front down and shake it until front lens module slowly moves out and drops to the nameplate ring. Then flip lens to the side, unscrew the nameplate ring and extract the front optical module.

It provides you full access to the lens heart – the aperture chamber. Surfaces inside are very accurately machined and blackened as well with high precision.

You can clean both inner optical surfaces if needed in future, or extract the aperture blades for maintenance.

Next step is to unscrew three small bolts holding the front barrel ring.

Be careful when removing the front barrel ring with filter thread – there is spring loaded bolt right under the aperture indicator red dot. Just look how accurately all aperture click-stop sockets are machined and then also anodized for higher durability!

Then you can remove the aperture ring. Note the socket position to fit the brass aperture transmission bolt when assembling it back.

Front barrel ring also has stopping bolt to limit the aperture ring rotation at end points, that is nice safety engineering decision to protect aperture transmission from breaking if applying too much force rotating aperture ring.

At this point I’m assembling everything back. Note that after inserting front module and screwing in the front nameplate – take some time to test assembled lens for optical alignment. If results are same as before disassembly – tighten the front nameplate and disconnect the adhesive tape from it.

Disassembly conclusion

It’s very impressive how much quality and accuracy is packed into developing of this ultra-fast lens taking into account its resulting affordable price. TTArtisan 50mm F1.2 in my opinion has a great maintainability level and relatively easy process of disassembly, especially when you know all steps and have proper skills. It was enjoyable to discover engineering solutions for aperture mechanics and also great to to see precisely machined and durable parts. One thing to remind is that focus distance precision can be easily calibrated without disassembly, thankfully to classic helicoid design with externally connected focusing ring.

The only negative mechanical impression from this overall great TTArtisan 50mm F1.2 lens is – the DOF scale is not reflecting real DOF size but showing much wider zone. I didn’t notice that initially because not using that feature often, but one of DPReview members pointed about that in comments, so it worth mentioning here. To solve that you can use black vinyl film to cover the DOF scale lines and use white/silver paint to mark more precise lines instead. Personally I don’t need that with shooting with Fuji X, in fact I don’t look at lens at all, but into the camera EVF, and even changing lens aperture by counting its nice audible aperture click-stops.

From the positive side – TTArtisan 50mm F1.2 is very inexpensive, greatly crafted, easy to maintain and enjoyable to use. Focusing is silky smooth and very accurate. It’s going to be my primary lens on Fuji cameras for a few next weeks to learn better how to use its strong sides.

Feel free to let me know in article comments if you have questions on TTArtisan 50mm F1.2 lens, I’ll be glad to explore more details.