If you don't know what is "bubble bokeh", then google for "Meyer Gorlitz trioplan samples". Impressed? now search Ebay for that lens, to see current pricing. Not cheap (>$300), right? but it is possible for you to get almost same results, by simply combining off the shelf items together, which will need less than hour and will cost you less than $60. No specific tools or knowledge is required, you will just need utility knife, hot melt glue gun, optionally - saw of some kind (Dremel, hacksaw, belt saw, etc.) and some simple components which can be bought from ebay.
Please note. This lens is for SLR/DSLR/Interchangeable lens camera, it can't be used on smartphone or fixed lens camera, sorry for that.
Before you continue, below is a little explanation text, why this lens is so different and what is the reason of getting one. Meyerl Gorlitz Trioplan lenses uses one of the earliest camera lens design, so called "Cooke Triplet", which originates in 19th century and was the first one, which had correction for most kinds of image distortion (in simple words, providing adequate quality). In modern days, this design was replaced by more advanced lenses, which provided even better image quality. But this particular type of lens remained quite popular, due to it's low cost and excellent cost/image quality ratio. It was widely used in film projectors and relatively unknown to SLR market, until DSLR revolution happened and curious and open minded people started installing all kinds of lenses into their cameras. They shortly discovered, that Cooke Triplet lenses produced interesting, "soap bubble" like blur in out of focus area, so called "bokeh". This trend become so popular, that Meyer Gorlitz re-launched their line of "Trioplan" lenses, after 50 years of cease of production! I just want to note, that even that this lens has "magic" bokeh, it still needs specific knowledge and practice, it is not kind of "just install and get things done" lens, whenever you use this adapter lens, or original Meyer Gorlitz production.
If you liked the result, but have no time to mess with adaptation, I've listed this lens on ebay, contact me for details.
Step 1: Materials and Tools
Below is the list of materials you will need for this project. I'm providing keywords, you can find them all on Ebay, Amazon, Etsy or at any common internet e-commerce store. These are very common, cheap parts. I'm highlighting keywords with BOLD letters, for each type
1. M42 lens adapter for your camera system - if your camera is Nikon, you will need M42 to Nikon adapter, if your camera is Sony E mount, you will need M42 to NEX adapter and so on. Just type into search "M42 your camera name" and it will bring you needed results. Depending on camera system, these adapters are sold in $1-$6 price range.Keywords: "Sony E mount to M42 adapter", "Nikon to M42 adapter", "Canon to M42 adapter" and so on.
2. M42 macro extension tubes. Sold usually as kit of 3 tubes, average internet price is around $3-4. I suggest you to get 2 kits, if you plan to go into deep macro. Keywords: "M42 Macro extension tubes"
3. M42 Focusing helicoid. There are many types available, but most cheap and common one, like 12-17mm will be just right. Do not buy longer one, because they are expensive and might not be usable for your particular camera system. Prices are in range of $16-20. Keywords: "M42 Focusing helicoid"
4. M42 camera body cap. Buy plastic one, no need for metal. $1-3. Keywords: "M42 camera body cap"
5. Triplet Lens. These are available on ebay for ~30 shipped from former soviet countries and come in different focal lengths and body types. They can be found using "Triplet lens" or "T-3 lens" keywords. The simplest in term of adaptation is "T-3 lens" (use this keyword for search). The best image quality is delivered by "Triplet-5" (Use this keyword for search). For this particular conversion, I will use F2.8/78mm in plastic enclosure (as most common and cheap one). Other types are also usable, but some will require much more adaptation, not given in this instructable. So what you need is a triplet lens in a plastic body. It can be 2.8/80, 2.8/75, 2.8/100, all will work. Please refer to attached image to get the better idea for which one you need. Keywords: "T-3 lens", "Triplet lens"
1. Utility knife. Any good quality knife will do just fine.
2. Hot melt glue gun with some glue. Also, even cheapest one will be fully enough for our task.
While these are not necessary, you might need them to cut lens body apart, or just make hole drilling easier and faster.
1. Saw that can cut thru plastic (dremel, hacksaw, bandsaw)
2. Step drill bit (and drill, of course)
Step 2: Making the Lens.
After you acquired all required parts, there comes assembly time. You should start with your lens, if you was able to get it in required shape (in form of small metal barrel), then you can skip text below, if not, and you got your lens in plastic enclosure, you will need to take that plastic enclosure apart. To do so, you'll need to cut it from both sides and then carefully pry apart with some strong, but blunt and flat metal object, such as screwdriver.
After you got your lens barrel free, you should clean it with knife or any other tool, if there are glue remains on it from outside, so it will fit into cap without any issues.
Next, take M42 cap and mark a dot in the center. Insert utility knife tip into that dot, slightly press down and start rotating the knife. It will start to cut out the hole slowly. Do not apply too much force on it, and watch your fingers. If you have cut resistant gloves, wear them. Check that hole diameter corresponds to lens barrel diameter, do not make it too large, or you will have issues fixing it later. Also, try to make that hole centered as much as possible, because if you cut the hole off-axis, your lens will exibit shift-lens effect, specific kind of distortion, which might good for experiments, but not good for daily use.
Insert lens barrel into that hole till it's beveled edge touches the cap, and using hot melt glue, secure it in the cap from the rear side, as shown on photos. Let it dry for couple of minutes.
After lens assembly is glued, now it is time to assemble whole thing together. Screw the lens assembly into focusing helicoid, and screw the helicoid into one of the extension tubes. Which tube(s) to use, it depends on your camera system. To check which one you need, start with any of them, try to adjust focus by rotating focusing helicoid and check results. If you can focus only on close subjects, but not on distant ones, you need to use shorter extension tube. If you can focus only on distant objects, but can't do close-ups, you need to use longer tube (or even several of them). For example, for Sony A mount cameras, you will need only one, longest extension tube to be used. For the Nikon, you will need to use medium length extension tube, and for Sony E mount, you will have to use all 3 of them together. Just remember, screw lens into helicoid, and add tubes between helicoid and M42 to camera mount adapter. If you mess with the order, you might get vignetting (dark corners) or other issues.
Step 3: Enjoy Your Creation! (and Some Tips Too)
Below are some photos which I've taken with the lens modified in guide as described. All photos were taken using Sony NEX-5N camera. Crystal close-ups were taken using double set of macro extension tubes, so you see now, why I recommended you to get 2 kits of them, if you plan macro shooting. I also should say, that this lens is a great choice as a portrait lens As you can see, I only managed to get the famous kind of bokeh in just couple of shots, but, I'm amateur photographer, so my knowledge and experience is quite limited, I hope, you will get much better results!
Update: After several days of experimenting, I've developed a small guide to such kind of lens, for optimum image result.
To get that famous effect, you need the following arrangement:
1. Background should be well illuminated, and preferably - highly reflective. Black, dull background will not work. Some glittery gift wrap paper will deliver almost perfect results (as I did)
2. Diameter of the bubbles depends on distance from background to subject and number of macro rings installed. In case of macro objects, optimum distance is about 30cm (samples 1,2,4, 14,15). Shorter distance to background will mean small or almost no bubbles (samples 16,17). If distance from subject to background is greater than 1 meter, bubble effect will be almost gone or very subtle (check samples 3,5,6,7,8,9,10). If you use no extra macro rings, bubbles will become flat (samples 11,12,13).
If you don't want to mess up with conversion and just need ready to use lens, please PM me, I'll help.