Cutting Diopters?

[Tito Ferradans]

I've been trying to get split field diopters for a while, but reasonable sized ones never pop up on ebay. So I thought "why not cutting them myself?".

No I got a kit of cheap Vivitar diopters and NO IDEA of a decent method of cutting them. I watched a bunch of youtube videos on how to cut a bottle but let's agree those cuts are not as accurate as the kind I'm trying. I also got a glass cutter, but I'm not sure I'm doing it right. 

Anyone ever tried this before? I'm open to suggestions.

[richg101]

remove from the metal housing and wrap the element in masking tape

draw a line down the middle

drill lots of holes along the line using a glass/ceramic drill bit - like an arrow head shaped drill bit - make sure the elements are in a shallow pool of water to aid cooling/lubrication during drilling.  don;t apply pressure - let the drill do the work.  high speed, use a battery powered drill for safety - 230volts and water don't go!

using a tile cutting fret saw slowly cut along the line - the drilled holes will mean you have less material to physically cut through

using very high quality 'wet and dry' glass paper from 240 grit down to around 1000grit to grind the edge flat.  the courser the paper, the more likely you are of chipping the edge so go steady when using he course grades.  grind 'edge ways' not 'across' to avoid chipping

once flat, apply a very fine chamfer to the cut edge using 1000 grit wet so remove any tiny chips.

thin down some enamel matte black paint and apply to the ground edge - thinning will mean the paint natirally absorbs into the frosted ground edge

dry in oven for an hour at 90degrees

 

since the cheaper single element diopters from vivitar are crown glass they are less prone to chipping  start on the diopter you;re less likely to actually use so you can practice.

 

DO NOT attempt this with cemented doublets!  you'll think you;re doing really well, then when that drill bit gets through the first layer and hits the second it'll shatter.

[Xavier Plagaro Mussard]

Rich you are an optic information infinite resource!

[Tito Ferradans]

So, I tried several methods at once (the burning line then cold water), glass cutter, exacto knife and ended up hammering a ruler to the crack. It turned out half ok, but I had to sand something like 1/8th of an inch. IT TOOK THREE HOURS. In the end, I used a black sharpie to darken the edge, but it can still benefit a little from more sanding....

For the next ones, I will avoid sanding glass and rough cuts. Later today I'll try the hot wire method. Got myself a transformer and some nichrome. Still two diopters to go, and a ton of bottles to practice.

[Hans Punk]

Would a 4x4 Tiffen close-up filter not work as a split diopter if positioned over half the lens? 

Maybe not strong enough? (can only find cheap +.8 online) http://www.ebay.com/itm/TIFFEN-4x4-FILTER-SQUARE-CLOSE-UP-DIOPTER-8-/381385016945

[Tito Ferradans]

8 hours ago, Hans Punk said:

Would a 4x4 Tiffen close-up filter not work as a split diopter if positioned over half the lens? 

Maybe not strong enough? (can only find cheap +.8 online) http://www.ebay.com/itm/TIFFEN-4x4-FILTER-SQUARE-CLOSE-UP-DIOPTER-8-/381385016945

I don't have (and don't use) matteboxes, but this filter, at this price, kind of solves another problem that I had, which was getting close focus for the Foton-A. The original diopters are almost impossible to find lately and their prices are a joke. This one is enough to cover 95% of the glass and at this price, it's good enough to give it a go! Thanks James!

[Hans Punk]

Cool!

Let me know what that Tiffen is like if you are grabbing one

If you don't have a mattebox you could always use a cheap 4x4 holder to 82mm ring (or similar) like this: http://www.ebay.com/itm/100mm-Square-Filter-Holder-82-82mm-Ring-Adapter-for-Lee-Hitech-Cokin-Z-PRO-Haida-/301914772006?hash=item464b85d226:g:DcUAAOSwFqJWrBiS

If you wanted to use that setup as a split diopter, you may be able to set the Tiffen halfway out of the frame and rotate that filter holder by adding an empty circular polarizer filter (remove glass) - as I don't think those cheap 4x4 - ring adapters rotate. This way you should be able to set different angles to your diopter split effect.

I was going to try one of those Tiffen +.8 closeups at some point (but with my Chrosziel mattebox) as I can rotate one tray and lock it half way out to see if it will give a workable split field effect.

 

[Bioskop.Inc]

5 hours ago, Tito Ferradans said:

I don't have (and don't use) matteboxes, but this filter, at this price, kind of solves another problem that I had, which was getting close focus for the Foton-A. The original diopters are almost impossible to find lately and their prices are a joke. This one is enough to cover 95% of the glass and at this price, it's good enough to give it a go! Thanks James!

Didn't you get the Foton-B with the A? They normally come as a pair & the B is a +2. And if you're still having problems, you stack the 2 together - but they aren't the best.

But if you're having problems getting close focus with the A, you could just use a longer taking lens - I had this problem with my pair of Fotons & this got me a lovely close-up shot of an eyeball (almost macro).

Or have I got your problem wrong? You want deep depth of field & close up at the same time - hence the split diopter?

The Schneider Series 9 split diopters aren't too expensive.

 

[Tito Ferradans]

5 hours ago, Bioskop.Inc said:

Didn't you get the Foton-B with the A? They normally come as a pair & the B is a +2. And if you're still having problems, you stack the 2 together - but they aren't the best.

But if you're having problems getting close focus with the A, you could just use a longer taking lens - I had this problem with my pair of Fotons & this got me a lovely close-up shot of an eyeball (almost macro).

Or have I got your problem wrong? You want deep depth of field & close up at the same time - hence the split diopter?

The Schneider Series 9 split diopters aren't too expensive.

 

Any chance you're confusing the Focar A and B diopters with the Foton-A (LOMO lens)? I've looked for the Focars for a while and missed a bunch by just a few hours, but now they're not in my priorities anymore.

The LOMO Foton-A (minimum focus at 1.6m) uses this diopter, which is ridiculously hard to find.

 

What I'm trying to get is both close up and deep focus at the same time, hence the split. I already added the 82-4x4 holder to my watchlist and I have a bunch of rotating Polas on the way, exactly for this job (since my Vivitars also don't rotate). I didn't get to continue cutting yesterday, but I'll keep the thread updated as I progress.

I remember seeing a bunch of cheap split series 9 a while ago, but I wasn't in the mood for them at the time so I didn't get them. Also, if I'm able to cut my own, I won't spend even $100 on a full set, and will be able to create as many as I want. MUAHAHAHAHA (evil genius laugh).

[Bioskop.Inc]

13 minutes ago, Tito Ferradans said:

Any chance you're confusing the Focar A and B diopters with the Foton-A (LOMO lens)? I've looked for the Focars for a while and missed a bunch by just a few hours, but now they're not in my priorities anymore.

The LOMO Foton-A (minimum focus at 1.6m) uses this diopter, which is ridiculously hard to find.

What I'm trying to get is both close up and deep focus at the same time, hence the split. I already added the 82-4x4 holder to my watchlist and I have a bunch of rotating Polas on the way, exactly for this job (since my Vivitars also don't rotate). I didn't get to continue cutting yesterday, but I'll keep the thread updated as I progress.

I remember seeing a bunch of cheap split series 9 a while ago, but I wasn't in the mood for them at the time so I didn't get them. Also, if I'm able to cut my own, I won't spend even $100 on a full set, and will be able to create as many as I want. MUAHAHAHAHA (evil genius laugh).

Fuzzy head this morning - absolutely confusing Focar for Foton. Now I see what you're doing!

Yep, you're best off getting cutting!!!

I remember a while ago, I was having a conversation (via e-mail) with QuickHitRecord about diopters & found a website that might do this sort of thing - can't find it in the ton of bookmarks I have at the moment, but do remember that it was in the US (I'll keep searching).

[Timotheus]

Cool Tito, I'm curious to see how this works out. Are you gonna show it off on your YouTube channel?

On a side note: would the square Tiffen filter that Hans mentioned be a good option for the 95mm thread of the Isco Video Attachment? Thanks guys!

[Tito Ferradans]

49 minutes ago, Timotheus said:

Cool Tito, I'm curious to see how this works out. Are you gonna show it off on your YouTube channel?

On a side note: would the square Tiffen filter that Hans mentioned be a good option for the 95mm thread of the Isco Video Attachment? Thanks guys!

Yep! I'm documenting the process for a video tutorial, IF IT WORKS. hahahahah

I think it would be enough to cover it, since 4 inches = 100mm. You'd have to be creative mounting it, but aren't we all?

[Bold]

On 4/13/2016 at 1:23 AM, richg101 said:

thin down some enamel matte black paint and apply to the ground edge - thinning will mean the paint naturally absorbs into the frosted ground edge.

Thank you Rich!  Just did this for the front element on a B&H and it made things way easier!

Cheers,

|. . | .|

[Brian Caldwell]

The Buhler Isomet is a nice low-speed saw that takes ultra-thin kerf diamond blades, but its very expensive.  I used one of these a lot when I was working on gradient index glass.  You might have some luck with a lapidary saw or a tile saw, and you might find a used one cheap.  The trick will be holding the lens properly, and make sure you put plenty of paint on it for protection during cutting.

[Tito Ferradans]

An image is worth more than 1000 tutorials. I'm still in progress. Last night we spent about 4 hours playing with wires and stuff, and then. Today I kept going for more two hours and voilá! I still need to polish the edges, but it's MUCH better than my first attempt through brute force.

Every step has been properly documented and I'll still repeat the process for the last diopter, hoping to get better shots still.

16 hours ago, Brian Caldwell said:

The Buhler Isomet is a nice low-speed saw that takes ultra-thin kerf diamond blades, but its very expensive.  I used one of these a lot when I was working on gradient index glass.  You might have some luck with a lapidary saw or a tile saw, and you might find a used one cheap.  The trick will be holding the lens properly, and make sure you put plenty of paint on it for protection during cutting.

Thanks Brian! I was trying to avoid resorting to expensive tools or specific services since they might not be available to everyone (if I were back in Brazil, I wouldn't be able to find a place that understood my goals, for example). Doing it with stuff that you can buy off any hardware store is more appealing to my current goals of making the knowledge and tools accessible to everyone.

That being said, I believe I would've gotten a perfect result with a saw and saved myself some jump scares, burnt wire, plastic, transformers, watching stuff glow red hot and a TON of time polishing edges. HAHAHAHA!

[Tito Ferradans]

 

2 hours ago, Zach Goodwin said:

Also I am not so sure about using that method, it is not perfectly spliced. Don't mind this question, if you could send that to some glass cutter to get that half of the circular diopter cut.

There is no perfect cut using the methods I'm trying. AND this was my first attempt with hot wires. This one is incredibly better than the first (I can actually use both sides, the first method completely ruined half of the circle), plus I'm didn't polish it at all yet. My goal is to spend $60 tops and end up with a full set (+1, +2, +4) and spares (the unused sides) plus the capability of making how many more I want at the only cost of the diopters themselves.

[Tito Ferradans]

Phew, this one is wrapped. Using different methods, I managed to get a decent cut, and here's a detailed tutorial on how to do it yourself!

http://www.tferradans.com/blog/?p=8922