Making the Mark III Film Digitizer

The Mark III enlarger digitizer is made with the head of a B&W condenser enlarger (Opemus II) and the column and head support of an LPL C7700 Color Pro. The digital camera is a Nikon D3200 (24 megapixel) with a Nikkor 55 f2.8 micro and PK13 extension tube to get 1:1 reproduction of 35mm negatives or slides. The negative carrier can be switched to a 120 type and the extension tube removed to reproduce 6x6 or 645 negatives or slides.

Version history made short: after initially experimenting with a colour enlarger head sitting upside-down on my desk with the camera balanced on the enlarger lens mount in the Mark I version, I chose the B&W condenser as it had more contrast and seemed sharper. This necessitated the Mark II, which had the vertical column from the LPL 7700 supporting the camera facing down, and the inclined column from the Opemus with its head facing up. Finally I got tired of working standing up looking down on the camera, and resetting a lot to go to 120 from 35mm, and the horizontally-oriented Mark III was created.

This is the setup for 120 negatives. The lens hood plus bellows extension makes sure only image-forming light is hitting the camera lens. The new 40 micro Nikkor can reliably auto-focus on the negatives, speeding the process up further. The PK13 extension is not needed for 120 or 35mm negs with this lens as it does 1:1 to infinity.

The first step in making the Mark III is to remove the C7700 head from its stand using the large black knob to the right of the head, and unscrew the large chrome steel plug that holds the LPL head. Then remove the column from its baseboard (similar large black knob at the front of the lower part of the column shown above). Dismantle the roller spring assembly carefully when the head support is at the top of the column. Remove the screws holding the column to its inner reinforcement casting at the bottom. Some screws are hidden behind the distance figures on the front of the column which can be slid up. The spring steel part of the roller tensioner needs to be removed from its nylon wheel. You may want to use needle-nose pliers as it has a sharp edge. Remove the four allen screws holding the rectangular part of the column base to the baseboard, and the the steel plate underneath the baseboard. You could build the Mark III onto the LPL baseboard, but I chose a more compact one that was recycled from a Meopta enlarging easel. I cut the LPL column down to 50cm length while it was dismantled, again to make the end result more compact and portable. I found that I was using the 20cm mark for 35mm digitizing, and the 30cm mark for 120, so there was no need for the 50% of the column.

The Opemus enlarger head is removed next, and the stud that secured it must be extracted (with vice-grip pliers) to replace with the large chrome steel fixing from the LPL head support.

The LPL stand mount can now be fitted to the Opemus enlarger head.

Placing the LPL head stand on the baseboard requires careful checking with a bubble level (or iPhone level app) and two sets of right-angle brackets and appropriate wood screws for the baseboard and metal screws and nuts for the head stand. I scribed a centre-line on the stand face to ease alignment of the Opemus head.

Once the holes are drilled and screws are fitted tightly, you should have a well-levelled head stand to mount the Opemus enlarger head into.

Remove the lens board from the Opemus by twisting it out of its bayonet mount. This allows greater clearance around the macro lens to avoid vignetting. I also cut down the bellows focussing shaft to allow the camera stand to approach closer. You may not need to do this, as it varies with the working distance of the lens you use.

Fit and align the Opemus head head into the LPL stand.

The camera stand is assembled from the column support bits and the nylon wheel from the spring tensioner, plus two more right-angle brackets of thicker metal. I cut the thick steel column baseboard support plate down with an angle-grinder, and needed to buy four 6mm diameter metric allen screws of 90mm length to attach to the column directly. I also cut the right-angle brackets where they over-hung the steel plate. The wheel assembly (which spins on left-over counter-sunk screws) is held in place by screw holes I drilled in the right-angle brackets to match where the 90mm allen bolts projected, and secured with some self-locking nuts. The sawn-off column can be slid into the head stand once the camera stand is assembled.

The wheel rim makes the column sit  ~ 2mm too high, so I made some tram tracks for the wheel to run in with an angle-grinder after scribing some alignment marks with a steel ruler and centre-punch.

The column can now sit level, and the tram tracks provide more lateral stability for its movement. There's no doubt a neater way to make the tram tracks, but they work.

If it is all bolted together correctly, the camera stand (former column support) should be level too.

I used a tripod camera plate with yet another right-angle bracket to fit the camera onto where the column slid over. Two more of the counter-sunk screws are re-cycled, as well as using two new allen screws into holes drilled and tapped in the tripod plate.

The former column rotate knob now becomes a camera height and swivel adjust knob. And that's it! You've assembled a Mark III digitizer.