I'm sure you have all seen the photoshopped picture of the Zoom Lens Coffee Mug. I thought it was a ridiculous idea but deep inside I wanted one. How hard could it be to take the optical glass out of an old lens and put in a drinking glass. As it turned out, not that hard at all!
Now you can make your own. But don't stop at something that looks like a zoom lens, make one out of a real zoom lens that still zooms, focuses, and changes aperture. In fact, with the lens cap on, no one would ever know!
Seriously, please let me know what you think, ask questions, post pics of your own conversions, and if you like it, rate it!
Step 1: Find a Lens
Bigger is definitely better in lens cups, so a big long zoom or telephoto, especially one with a large front lens will make a generous coffee cup or cocktail glass, but you could make shot glasses out of 50mm lenses (if you can find a shot glass that will fit).
The one I found was around NZ$5 and was a Star-D brand 80-205mm f 3.8 lens. I wanted a bigger one but I didn't want to spend too much before I knew whether it was going to work or not.
I also like the old 1-touch zooms (same grip zooms and focuses) so it seemed like a perfect "doner" lens.
Step 2: Disassembly - Part 1 - Outer Optics
The front lens can be the most difficult but it is much easier if you aren't worried about scratching anything. Usually, the front lens is held by a ring that has all the words and numbers on it. If you look closely where the lens cap hooks on, you'll see it is a very fine thread. This is the thread that filters screw onto and it is what the ring is screwed onto as well.
Camera techs have different sized rubber rings called lens wrenches that they push onto the ring and twist to "unscrew" them. I used a small screwdriver and pushed it counter clockwise. It didn't take too much force to loosen it, then it's just a matter of unscrewing it with your fingers.
Under that lens was another, also held in by a ring with a notch on it so same technique.
Under that was one held in by 4 screws, then another with a threaded ring.
Keep going until you can't remove any more lenses from the front.
Step 3: Disassembly - Part 2 - Inner Optics
Just keep taking pieces off like you did in the last step until you get the outer cylinder separated from the inner zoom mechanism.
Take off the rubber grip to access screws that could help separate the zoom mechanism.
Step 4: Disassembly - Part 3 - Zoom Mechanism
I found that there was a front section, a back section, and central tube that connected the front to the back. Then there was the zoom grip that slid over the three parts and that was basically all that was needed to get the lens back together.
So the last two photos are these skeleton pieces in their most collapsed then their most expanded configuration.
Now its time to go drinking glass shopping!
Step 5: Shopping for a Drinking Glass
I took my skeleton lens to the Christchurch Supershed (our city recycling centre) where I found a few likely contenders. Two glasses seemed to fit ("rounded base" and "tall shot glass" in the pic) so I payed 25 cents each for them.
I liked "rounded base" glass because it was bigger but the only way to make it work was to not use the original center tube of the lens and somehow attach (glue or screw) the inner section to the sliding zoom section, then attach it to the outer section (glue or screw).
Because the "tall shot" glass was wide at the mouth then tapered, it was smaller in diameter than center section. This was great because I could attach it to the re-assembled.
Step 6: Lens Cup Assembly
Because the lip of my glass was just smaller than the opening, it sat a bit too low to be secure so I added a spacer that came from another part of the lens to raise it a fraction (pic 3).
With the glass in place (pic 4) I then screwed down the original outer ring and tightened it using a small screwdriver (like I loosened it in the first place).
You can see in pic 6 that the outer ring just holds it by the lip of the glass but it is very secure and doesn't move at all.
That's all there is to it!
Step 7: Finished Product!
As you can see, you can drink wide open (f3.8 in pic 2) or with increased depth of field (f22 in pic 3).
You can also zoom and focus while drinking, and if you are away from your drink, you could put the lens cap on it to keep dust and your mates out of it.
You might also be able to take photos with it.... I didn't have a camera with a Pentax K bayonet mount, but I don't think the shot glass offers much in the way of optic.
Please let me know what you think, ask questions, and if you like it, rate it!