Nikon HE-5 Lens Hood Extension

My foray back into panoramic photography gave me an excuse to buy a DSLR. Owning a DSLR has given me an excuse to search eBay for deals on interesting camera lenses. In December that led to the purchase of a Nikon 600mm f/4 AiS manual focus super-telephoto lens. My particular copy appears to have been owned by the Dallas Morning News at some point—as that's written on the side of its trunk case. I trust it is a good retirement activity for this lens to look at birds and airplanes; activities which I also enjoy. It's incredibly heavy and impractical to carry around, but along with my modified TC-20E III, it's pretty much like looking through a telescope. I also added a dandelion CPU to the lens to get some of the benefits of more modern kit, like focus priority shutter and EXIF lens info.

That excellent eBay deal unfortunately meant there were a few compromises, like the beat up case. The most significant was that the lens was missing the HE-5 Hood Extension. Having such a large front element meant that it's tricky to shade the front element from incident sun exposure, which can cause washed out images and lens flare. It took about 6 months to find a hood on eBay, so I bought the first one I ran across, even bidding it up while on vacation.

I was elated to finally complete my kit by adding this part—but it turned out upon receipt, the hood extension wouldn't mount to the end of my lens. After a bit more research online, I was able to determine there were 2 plastic mounting tabs missing from the hood. These were subtle and frankly I hadn't noticed them on any pictures of hoods while researching and purchasing the hood online. The seller was happy to help get things straightened out, but had no ability to magically conjure up these parts. I decided that instead this would be an opportunity to restore a rare old piece of equipment and keep it from the scrap heap. The missing knob was easy (albeit expensive) to come by from Nikon, as the part is still used on modern lenses. The screw on the new ones is a bit longer, so I just removed the black aluminum cap and screwed it into place. Next were those pesky tabs. I knew it'd be impossible to find original tabs I needed, so I studied all the photos I could find, approximated what size they'd need to be to mount the lens, and started modeling in Fusion 360. I asked for some help on the DPReview forums, and got some help from the community there. A quick trip to the Shapeways website, and I had my first revision in hand.

Of course the first revision didn't fit, so I sanded them down, made them work, and modeled up the second revision. This time shrinking the tabs and rounding them off for easier mounting. The trimmed down version worked like a charm, and Shapeways was very kind in replacing one of the two that came out a bit deformed from the printer. Their new Professional Plastic (HP PA12 Nylon Plastic) is extremely durable and seems like it'll be perfect for this kind of mechanical part.

The final trick was locating original screws to match the 25-year-old ones in the hood. This one was trickier than expected. While it was soon clear the screw diameter was M2 and length was 5 or 6mm, I couldn't quite make sense of the 0.6mm thread pitch and kept questioning my caliper measurements. I spent about a week searching through different screw standard specifications until I finally encountered the JCIS Type-B Thread Forming screw. It turns out this screw is specially designed to be self tapping, and the body of the screw is in fact more like a rounded-off triangle than a cylinder—a design I eventually learned was called "trilobular." Of course it had a standard JIS cross point (not philips) drive and was black in color. Knowing the screw specs was helpful but not sufficient because however hard I tried, I couldn't find a supplier in the US. Eventually Saima Corporation in Japan responded favorably to an inquiry for a quote, and I soon had 1000 of exactly the screw I needed. (Please let me know if you need any of the 996 remaining screws I now own…) They were an excellent help to completing this project.

I still have a bit of restoration to do on the 600mm f/4 AiS. I need to craft a workable lens cap and the rubber ring on the end of the lens is still missing (anybody know of reputable 3d-gasket printing outfit?), but these all seem doable now that I've got a working hood extension!

I'm looking forward to more birding expeditions this fall, no matter the angle of the sun. :)

HE-5 Tab
3D Model

Kaidan QuickPan IV Detent Discs

Recently I've been getting back into panoramic photography. It's been a lot of fun, after perhaps a decade long hiatus, to capture spherical panoramas again. I picked up a mint condition Kaidan QuickPan IV tripod head with Spherical Bracket to relive my early 00's QTVR days, while securely mounting my new Nikon D810 camera when capturing photos.

In order to capture a panorama I use the tripod head to take evenly spaced photographs in all directions. It uses small plastic disks to click into the right position, so the photos are easily aligned.

It works great, but I found that I needed a different set of detent discs than came with the tripod head. I think there was some standard set—but to achieve 25% overlap with my 17-35mm lens, I calculated 7 photos would be optimal, but that value wasn't included in the kit.

I figured it would be nearly impossible to find additional Kaidan detent discs since the company is now defunct, so I set about making my own through Ponoko. I used my vintage Browne & Sharpe Dial Caliper to measure the original discs, then drew up some new ones using Inkscape. Ponoko gave me a $20 coupon for signing up, so I got my set of 5 laser-cut discs for less than $10 shipping & handling. The quality is excellent, and the 1.5mm Delrin material is perfect for the discs.

Reproduction Detent Discs

The fit is a bit snug, but they work great! I've made the discs available for purchase through Ponoko here, and also am providing the design file for download here. While it's unlikely many folks are looking for detent discs for the long discontinued QuickPan IV tripod head, I figured it'd be nice to have some source to get them in case anybody needs replacements.

I haven't yet captured a panorama with my new discs, but last weekend I went to Treasure Island and recorded the image below. I'm still working on HDR, color, and stitching details, but still happy with the results.

Treasure Island

Place Matrix

Reddit put together what was ostensibly an April Fools' joke that allowed users to "place" one pixel at a time on a large canvas. It turned out to be a really awesome social art project; groups needed to collaborate to get anything done because there was a long delay between opportunities to place pixels.

Update: Incidentally, Reddit published a great article today about how they built r/Place. Highly recommended.

Update 2: I wrote a technical description of how I built Place Matrix.

Because I'm not a big Redditor, my friend Andrew showed this to me, I think after a post on Twitter. We had a great discussion about the emergent behaviors that occurred with such a simple system on Saturday night, and talked about how such constraints can make things a lot of fun. I had just finished building my p11-matrix project from Boldport Club, and had connected it to the web with an API that only allowed toggling a single pixel.

So the next day I woke up and realized I had to port Place over to meatspace and started hacking. Thanks Andrew for helping incubate the idea. I'm not a web programmer, but my Python skills aren't too bad so I found a tutorial on Medium and started setting up AWS Elastic Beanstalk. One full Sunday of programming (followed by 3 back-to-back late night debugging sessions…) and it works. Lots of thanks to my friend Charlie for help and support through these manic last couple of days, and to the Saar for making Boldport Club and inspring projects.

Check it out at Place Matrix.


Weston 1293 Nixie Tube DVM

A couple of years ago I was at an estate sale with my mom and picked up this interesting Weston 1293 Digital Volt Meter. Could not resist nixie tube test equipment for $15.

Weston 1293 DVM

I'd learned a lot about how it worked from a web page describing the Weston 1294, though that web page appears to be completely gone from the internet without a trace—not even a page is cached in the Internet Archive. I hope that site has a shorter hiatus than mine did…

Internals (analog and digital boards)

It had been sitting on my shelf without much use in the interim because it was hard to use with just bare wires soldered on a connector on the back, so finally I've gotten around to building an enclosure for it. I also found an original manual for the Weston 1294 on eBay, which provided more context, though there are numerous differences.

Enclosure Construction

Construction was relatively straightforward, with internal wiring mostly implemented with crimped spade termination and plenty of heatshrink. The most interesting part of the construction was cutting out holes in the aluminum front and rear panels of the enclosure. First I marked the cutouts using blue masking tape. Then I roughed out the holes with a drill and a jigsaw, finally finishing it up using a file. I think this practice of roughing out a hole and filing it to the line must be a standard technique, but I didn't really know how to do this until I saw the amazing craftsmanship on the ClickSpring YouTube channel, where this technique is used a lot.


Omnichrome 643

Recently I purchased a Melles Griot Omnichrome 643 laser on eBay (as noted in my laser inventory). I was happy to find it arrived in great condition after making the long trip from Canada. I had long wanted an Argon-Krypton laser capable of producing a wider slice of the spectrum—"whitelight"—but they seem to be quite a bit more rare than plain old Argon-ion lasers, and usually more expensive. Got lucky with this one.

It came with almost everything including the laser itself, power supply, cooling fan unit, and even a printed manual. It was almost ready to run out of the box, but I needed a cable that connects the laser head to the cooling unit, an air duct, and also a way to plug it in; it draws 20A @ 240V.

First I wired up a 10 gauge extension from my electric clothes dryer outlet with a NEMA 10-30 plug to a NEMA 6-20R receptical. I ordered 25ft of 10/3 SOOW cable and the plug from Amazon and picked up a "handy box" and the receptical at Lowes. Working with these heavy, flexible SOOW cables reminds me of my days in highschool technical theater…

I couldn't find one on eBay, so parts for the other cable required a new crimper (Engineer PAD-01), a Digi-Key order, and tracking down some 18/6 SOOW at a good price. Fortunately it was easy to defeat the fan interlock with a jumper and use another blower I had for my other Argon laser in the mean time.

So after just a bit of wiring and basic external cleaning I was able to get it running in top shape. I made a new jumper remote plug to run it in constant-current mode and walked the mirrors to get the peak output up to about 83mW at max current. I figure the cross-continent shipping probably wasn't great for mirror alignment, but no worries now. The specific model number is 643-OLYM-AO3, which I suspect means it came from an Olympus confocal scanning microscope, but have no explicit specifications for the unit. I received the tube with about 570 hours on the run time meter, so it is far from new but still has great light output. Anyway, on to the pictures!

One day I think I might be interested in getting RGB optics instead of the RYB this unit comes with so that it'd be more appropriate for laser display purposes. Some folks suggest that it is best to appreciate the yellow-green line for what it is and avoid the trouble. Guess we'll see if I come across the right kind of output-coupler optic. Next project is to build a small digitally-controlled remote for the 171-B power supply.

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