Homemade 35mm -- Edited Copy for Reading

[Filip Kovcin]

hello there,

as far as i can see - there is no info about manufacturer of frosted fake cds.
i have suggestion that anyone who knows the manufacturer who is definitelly NOT producing frosted/sanded CDs - to put it on the list, so we will be closer to that real one.

second thougt - does anyone knows how to make CD frosted with some chemicals? maybe this is much simpler than making it "mechanically"

filip

[Jim Lafferty]

Just picked up a cheap fresnel and it doesn't help me -- at least, not yet.

I'm convinced my focusing problems are a flange focal length issue, but I've yet to find the proper distance between my lens and the focal plane (the GG). It's better, but still not acceptable.

When/if all else fails -- is a longer distance between the lens and the focal plane the best solution?

Incidently, I've got a Nikon Nikkor 50mm f/1.4 lens, part # 3958069. If anyone has the info that Google doesn't seem to turn up for me, I'd love to know...


edit: Helen -- the link you posted was down when I first clicked on it -- the link now works and I see that the distance for a Nikon SLR lens is 1.83 inches. Thank you for the info!!

- jim

[Louis Feng]

The focal plane for the 50mm lens are 50mm away from the lens. That's the distance from the middle of the mirror to the focal point. On the lens it usually says something like f=50mm. If it doesn't say that, I would assume that because it's very common. If you measure the thickness of the camera, it gives a good approximation of where your GG should be.

[J. Clayton Stansberry]

Anyone find out where the pre-frosted CD's come from? So far from the thread this is what I have:

CD Packs that do not offer Frosted CD's:
Imitation
Fugifilm
Philips
100 pack $20 at Best Buy

Possibly have it:
Khypermedia
Memorex

Please let us know and add to the list so we can find out which pack it is...and then run out and buy their stock because you know they will be selling a hell of a lot of them!

Agus,
That beta footage is awesome! Do you have any recent pics of your new design so we can start drooling for the commercial version? Thanks.

[Bob Hart]

Chemical means of achieving frosted surface on disk!!

Those chemicals might be a little dangerous.
There may be some solutions but it would be irresponsible to post them here.

It could render me and the host of this service possibly liable for suit should tiny vexations like chronic dermatitis, blindness, chronic obstructive airway disorder and death emerge as collatoral consequences.

This is one area I would commend anyone not qualified to avoid like the plague. If you don't know it or can't do it, don't try. Chemicals are very socially enlightened. They don't discriminate. They just drop everybody. Seek help from somebody who has accreditation in this very specialised industry.

So you are going to go for it anyway. Whatever chemical you choose to experiment with, be extremely careful, avoid the vapors and don't leave the stuff lying around for little bro or sis to encounter. And for heaven's sake read the Hazmat notes, know what to do beforehand if it all goes wrong. Devise your personal or household counter-disaster plan if you have not already.

I don't think you will achieve by chemical means, anything you can't do with a lot less risk or hassle with graded silicon carbide grit or wet and dry silicon carbide grit papers or jobbing the task out to somebody who can gritblast with graded grits. That final 5% to perfection everybody looks for might only be achieved by experienced practitioners of specialised crafts.

The frosted CD disks people have been mentioning here?? Are they "frosted" right through the thickness of the disk or only on one surface??

If the "frosted" feature goes right through the full thickness of the disk, you will likely get inferior resolution, a halation effect into neighbouring image from pinpoint highlights and lower light transmission.

If the disk is only lightly translucent, your camcorder is going to also see through it into the front lens and you will get a hotspot in the centre of your recovered image.

There were two versions of the small "Pringles Chips" container press-on caps. One cap which originated from Belgium was a clear plastic with a frosted finish applied to one surface. These containers made excellent pinhole cameras for kids. The US cap was made of a translucent plastic which did not work as an image plane.

[J. Clayton Stansberry]

Another solution might be to do what they do to make ground glass. It may also work on the clear CD's...just another thought...

Check out this website:
http://www.phototechmag.com/previous...kas/dokas.html

I am sure there are others, but may be another option.

Bob,

Agus has stated, after using the frosted CDs, that his resolution increased and there weren't any problems. In fact, by his latest footage, I would say he pretty much got it right! Don't know about where it is frosted as I can't seem to find one of these bloody things:( Will let you know if I can ever find one.

[Paul Doss]

Agus Casse <btw Paul, your designs wont work, i tried them and they are no good.>

You are absolutely right! The one or two mirror versions do flip the image vertically but not horizontally. Back to the drawing board. Looks like the only way is to copy the SLR in as far as the light path through the viewfinder.

Paul

[Don Berube]

For what it is worth - In the past, I have had clear pieces of glass turned into frosted pieces very nicely via sandblasting. I didn't do the sandblasting though, it was done by an ordinary local glass & window service company. The pieces were very consistent with each other and it only took the shop an hour to perform the job.

- don

[Randy Reyes]

I have one frosted CD that came in a spindle but I forgot which brand it came i in. It could be Maxell or Primaris. They are definitely not from Fujifilm... :]

http://www.imagestation.com/picture/...e/fa3e9a51.jpg

http://www.imagestation.com/picture/...b/fa3e9a4e.jpg

http://www.imagestation.com/picture/...0/fa3e9a54.jpg

[Jim Lafferty]

Well, I got 'er functional today -- she's not pretty yet, and without a rail system in place the image shakes a bit much (going in and out of focus with it.) But, what can I say, I'm proud:

http://ideaspora.net/agus35/agustest.mov

(12.8mb Quicktime 6)

- jim

[Don Berube]

I am sure that someone has already pointed this out earlier, but here goes. The frosted plastic that you are using in place of real optical ground glass is deteriorating the image too much. It is also causing you to lose too much light. Earlier, someone had posted something to the effect that "if you use ground glass, the image will be too bright". Well, if that is the case with this design, then the design is flawed and should be reworked so that you can use real optical ground glass. So far, none of the sample clips I have seen show an image that does not look degraded by the plastic. No offense, just an observation.

- don

[Jim Lafferty]

Yeah, but expense and weight have to be factored into the design, as well.

I've got about five "ground glass" CD's here -- they cost me nothing more than I'd long ago spent on CDR's. If I drop them, or decide I want to mess with them to get different optical effects, I don't have to sweat their replacement and the costs incurred.

The question isn't (for me at least) 'How can I get the best image possible, at the expense of other considerations?', it's more 'How can I create an image that's acceptably interesting with the things I have at hand?'

- jim

[Don Berube]

I would still say that as long as you limit yourself to using plastic in the image chain, you will be self-defeating yourself. Why waste all that energy trying to produce an "acceptable" image with plastic when you have the potential for an excellent quality image with glass? It's a simple thing that we have known for years - plastic does not produce good results in photography.

You mention "expense" - what is your budget cap? C'mon save yourself a lot of frustration and wasted effort, spend a little more and put some real glass in there. I dare say that it is not impossible to find an affordable glass solution by modifying the design a bit. Regarding finding an affordable piece of glass - has anyone thought of using a 2mm thick 4x4 or 3x3 mist or fog filter from LEE Filters or Cokin? Or perhaps an even-more-affordable resin filter from LEE or Cokin? Even a resin filter would be much better than plastic - but you really should use glass.

Again, no offense implied here, I'm somewhat impressed with what you are doing, really. It's just that the image is too deteriorated.

- don

[Agus Casse]

New version with higher res...

http://altoque.tv/35mmAdapter/35mmtestBETA.wmv

Don Berube is right we are loosing a lot of light and considering that still havent installed a dove prism to correct the image. Still, cost vs performace is amazing... DOF is great, my TRV18 is kicking ass with no modifications or aditional investment.

hey Jim, thanks for that credit dude !!

i see that you are having some vibration problems, are you using a cd motor ? did you sanded the cd or was a already frosted one ?

[Agus Casse]

i think they can cut the glass center just like the cd, i saw some stores that have some glass windows with little holes. i will try up with glass next week if i am lucky, i really need to improve this for the comercial version, also i am still working in flipping the image.