I am really happy whit my GG but still looking for something better and static solution. I can say that I can see grain in some rare situation but it's still pretty hard to see it. It's probably also because I am using a VX2000 that as the best low light performance ,the result are less good whit my VX1000.

Alain

While in the kitchen at our church, I came across a thin cutting board/sheet thing that was white and semi-transparent. (Can't see through it unless the object is right up against it on the opposite side - similar to a ground glass.)

It reminded me of the microcrystalline in that it appeared completely grainless when held up to the light. I didn't have a lens on hand to test it, but it sure looked like it would work. It may have been too thick, however, but I don't think it would be that difficult to find someone that could 'slice' it thinner.

I've been looking around for one of these cutting board things and the closest I've found was a multi-pack (different colors) from Wal-Mart. However, these were grainy on both sides, so they wouldn't work. I've asked around and nobody knows where it came from.

Any ideas?

from heaven? :)

New York has plastics companies on Canal street. I bought two 58mm frosted samples but the grain appears to be too large -- would be perfect for a spinner, especially given that you can custom order any diameter and have them center cut your hole. Will return to see if I can find a superior molded/etched surface, and if so I'll likely pass the info along here.

The pieces I purchased were $5 each, cut to spec while I waited in the shop for about ten minutes :D Sure beats grinding glass where time and money are concerned.

Also, my tutorial will be getting an overhaul shortly. On that note, if you're using white PVC to construct the body of your adapter, Rit brand dye is what you should be using instead of spray paint to color the adapter -- at least the interiors. I've found in practice the paint chips and can fall to rest on the three+ glass surfaces of the adapter.

Rit can be found at Pearl art supply stores or ordered online for about $1.75-2.50 a batch -- double up on the batch and dissolve it in just enough water to submerge your parts (after having scuffed them up thoroughly with sandpaper) -- or about four cups.

Bring the bath to a simmer. Stir in a tablespoon of laundry detergent. Drop your parts in and stir them constantly for about 30 minutes. Turn the heat off and stir a bit more. Let the parts soak over night.

Do not substitute Tintex brand dye, which is mostly comprised of common table salt. Do not have anything you value in its current color state near the stove. And above all, wear gloves.

- jim

Purpose of GG?
 

What exactly is the purpose of the ground glass? I am able to see the image projected from the lens on a clear CD or a clear UV Filter. Am I missing something here?

GG purpose and nomenclature
 

People on these forums (myself included) tend to use the term 'ground glass' when what is really meant is 'imaging plane.' A 'ground glass' is a specific material treated in a certain way - and works as an imaging plane. Of course, so do frosted/scratched cds, strips of satiny magic tape...

In order for the depth-of-field characteristics to be captured, the imaging plane must have enough diffusion to actually become a projection screen for the 35mm lens. If you're actually seeing a flat image which is materially on the clear cd/uv filter, than you may have fingerprints, or some other material on the surface. If not, you may also be looking through the clear disc/filter and seeing the 'aerial' image from the lens. If this is the case, your imaging plane is serving no purpose. Unfortunately, this will not maintain the depth-of-field characteristics of the 35mm lens and will image to your CCD exactly as if you weren't using an adapter (except a little darker and upside down).

Jim - that's exciting. Definitely let us know what you find. My single-ply architectural mylar film secured to my clear cd works pretty well, but I'd love something with an even finer grain. (I'd rate it at about 9 micron gg size... okay for spinner which is what I have, but I still see a fairly noticeable grain-swirl which takes some massaging in post to remove).

Brandon,

A GG must strew (not refeflect, and not only let through) the light.

The only way to do this is a structure of different translucent areas. One more, the other less, but both are translucent.

So the ideal GG is:

The structure, what ever it be, is smaller than the smallest pixel of the camera
The structure must be even
The structure is only on one side (or in the middle) of the glas (or plastic)
The structure is also more thinly than the smallest pixel

The GG lets light through, as much as possible and if you look by the glass, its a little like milk, not like glass, so you can not see any details.

Rai, something that has come up here before is using microlense viewing screens (and also low angle hologrphic diffusers). People have said they cannot be made fine enough, but the sensor chips themselves are covered in smaller microlense arrays to maximise light to each pixel. What do you think of the possiblity of using one of these to straighten the light? I know your company works on cinematic optical stuff, so maybe you can advise us on this?

Thanks

Wayne.

Wayne, you are everywhere, (smile)...

Yes you are right. Self-made-people cannot made it fine enough, but... I only say: nothing is impossible...

I will email you, but today i am very busy

You wouldn't believe it, I think I was here before I was over at the hd threads (and yes, I am registered with every major forum, but only concentrate on this one ; ).

Filip: LOL!

Microcrystalline is the finest thing I've used for an intermediate image surface, but it is so hard to work with that I have thoughts about just shooting w/ open aperture and ND filters at telephoto to achieve the DOF I want. :-) Anyone else been thinking like this?

- Frank

I've heard the there is/was a company who made GG's using paraffin... I don't know what the company is called but they sure know how to get rid of the bubbles and uneven surface..

while writing here I wonder Frank if the wax-solution softens the image, like a soft filter? Looks like that on the test pictures

I'm not sure if anyone other than Bosscreen uses Paraffin wax to make viewing screens, but yeah...I wish I knew how they did it.
Not only are bubbles a problem, but little pieces of lint and dust can easily get into the mix and show up in the footage. My kitchen isn't the best workshop for this. :-)

About the diffusion:
According to the manufacturer, Microwax has a very low refraction index. Couple that with its small grain, and it gives a pretty sharp image. I have some new footage captured and will try to post something tonight or tomorrow. (Some stills and a small pan shot.)

- Frank

Do you think you could post a 10 frames clip with the setup you used on http://www.frankladner.com/testpics2.htm too? I would thank you forever!

You can export it as a jpg-animation if you want to save space.. btw, i have 400mb hosting so just tell me if someone of you guys want me to host something for you ;)

/ Eric

Eric: The images on ttp://www.frankladner.com/testpics2.htm are pretty grainy - especially noticeable in the moving footage. I deleted the original footage those framegrabs came from, and I have likely recorded over the footage on the DV tape. (Using the same tape for all my 35mm adapter tests.) However, if I can find it, I would be glad to put up a sequence of frames.

Also, while I'm here - I spoke with someone about getting some microcrystalline wax with a 170 degree melting point, which is above what I am currently experimenting with. Does anyone happen to know what the melting point is on the wax in a Bosscreen?

Thanks!

Wax Bubbles and Lint
 

If/when I move to experimenting with micro wax, my efforts would likely surround sandwiching the melted wax between glass extracted from two filters, and applying even pressure across their surfaces with a vice. This way, you'd force the bubbles to the edges, and also solve the lint problem by making both surfaces glass (much easier to remove lint from glass than wax.)

Of course the problem would be applying enough pressure and not too much, coupled with keeping the glass from being scratched in the process.

That's the theory anyway. In the meantime I'm waiting for my WAO 5, and if this proves to be a sufficient improvement over my current setup, I'll forgo the wax idea and just start shooting.

- jim

Whoops
 

As it turns out, dyeing PVC complicates things -- in order to get the color to set in the plastic properly, the dye bath must be near boiling and stay there for the duration (about 30 minutes). To my surprise, this actually shrinks the PVC by about 3mm, just enough to make previously tight fittings impossible.

My only recourse at the moment is switching to a 55mm filter for my GG (down from 58), and file down the interior edge of the piping so that it slides over my achromat.

In the future, I'll be dyeing both halves as a solid piece, with metal rings at either end to preserve the proper diameter.

I hate learning these sort of things the hard way :/

- jim

updated with some new movieclips and pics.

i'm still into the cd-adapter (agus). do you think there are any solutions to make a static adapter with no visible grain? i mean, the testpics i've seen from frank, why do you need it better?

- Frank
What's the bad thing with the wax GG you used for testpics3.htm? Cause what I see looks great. Sell me one ;)

www.de-interlaced.net/mini35

sorry, always forget to copy-paste the link

Eric: Thanks for the comment!

I don't think what I have would be suitable to sell, and I have no clue what it would sell for. I have yet to come up with a repeatable way to get a flawless wax layer.

i found some instructions here: http://ideaspora.net/aldu35/index.html

i get most of it but some parts are confusing. i have a Konica Hexanon AR 50mm F1.4 lens. pertaining to the instructions, i will need a F-Mount. the one the author of the instruction uses is this: http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=77558&is=REG

i searched konica mounts at bhphoto and came up with these results: http://www.bhphotovideo.com/bnh/controller/home?ci=1&sb=ps&pn=1&sq=desc&InitialSearch=yes&O=SearchBar&A=search&Q=*&shs=konica+mount

there are a number of mounts available and i don't know which one to get that will fit correctly. can someone let me know which one is the correct mount to get?

also a +7 diopter is needed. well i don't have $210 to get one from century optics. can someone link to me to a search on ebay that has +7 diopters for around $30? thx

Hi Danny,

I'm the author of the page you site:

The F-mount is for Nikon lenses only -- I don't know what kind of mount you'll need for your lens. At worst, you could call B&H and they'll know the answer -- or visit if you're in town.

For diopters/achromats/macros, check around on eBay -- cheaper ones can be found provided you know the threading size on yor cam (58mm if it's a GL1 or GL2). There are step-up rings available if you need them, e.g. from 55 to 58mm, and the like.

Your lens will have a different FFL than mine, incidentally. Check the chart linked on my site.

Also -- get better Aluminum Oxide than what I've rec'd on the site -- WAO 5 from gotgrit.com for $1.75 per 1/4lb (all you'll need and then some), and $6 shipping. WAO5 is GREAT, but takes a long time to grind out scratches (should they arise.)

- jim

hey jim, thx. i have the same camera as you so i shoulld be able to follow the instructions exactly. what should i search in ebay to find the diopters? i tried a few and didnt come up with anything.

and can you give the description/label of the pvc's you bought? im gonna go to home depot tomorrow to get some.

also would it be better to get a +10 diopter or a +7?

Markings along the interior ridge of the female half of the PVC coupling (near the threading) are as follows:

NIBCO NSF dwv D2665 PVC I UPC(R) 4803 2 USA "2"

Where the 2 in quotes is actually a backwards 2, and the (R) is a reserved 'R' in a circle symbol. They come as a pair, so if you find this half, you just need to find the other component.

+10 diopter vs. +7 -- there's no answer I can give, as I've just the +7 and can't speak directly on the +10. Just note that power of diopters guage how close an object can sit relative to the lens. Also, there my be some adverse consequences to going too high with your diopter's power -- chromatic abberations at the image's edge, e.g.

As another aside: grind your glass as it's shown on my page and disregard the text that says "I've just discovered that it's possible to grind with the filter ontop of the glass..." This has proven erroneous.

Also, do not paint your adapter's interior black -- some other method of coloring would be best if possible, though plastic dyes or bonding paints are very expensive. You can Rit dye the coupling, though to get the dye to truly set, the dye bath must be simmering and things need to sit in the bath for 30+ minutes -- this has the adverse effect of shrinking the PVC, and the GG then needs to shrink (to 55mm) and the part of the coupling that slides over the diopter is no longer large enough to do so. You either then have to scoop out the rim's interior with a dremel or the like (a file works but is very tedious), or devise an altogether new way of attaching the setup to the cam.

Painting the setup, however, is a bad solution as the paint chips and falls onto the glass elements when you attach or detach the setup.

Good luck!

That's all for now,

- jim

cant i just spray paint the outside?

No. If the interior is left white, you run the risk of incidental light polluting your image. The interior must be a flat black.

You can paint the exterior in addition, if you'd like, to whatever you're successful with doing to the interior, but painting the interior is a bad call.

- jim

powder coat

That's a bit pricey, but potentially the "right" way to do it, Brett.

Rit dye, on the cheap, is a good solution provided you've got a smaller GG and a dremel.

There are plastic paints, as well, but they run in the neighborhood of a powder coating setup where price is concerned -- $135 for a bucket.

- jim

Powder coating needs a conductive object to allow the electrostatic powder application to work. There *may* be a pre spray to give it some.
Also, Powder coating involves baking the part in an oven to melt the powder onto the object.
Things tend to melt!
Are these parts plastic ?
-Les

If you are not too fussy about the surface finish and are careful not to paint on mounting or contact areas, it may be feasable to mix some black pigment into blue glue (PVC pipe cement) and paint the interior with that.

I haven't tried it and the substances may be chemically antagonistic. Another way might be to prime the interior with blue glue and paint over that. Blue glue is a BAD chemical in terms of health and longevity so use only in a well ventilated space and don't breath the fumes.

I went with a solvent based blackboard paint and it hasn't come off yet, but it may well do so in the future. I have used blackboard paint on glass and to stabilise it, I added some cooking oil which almost stops the setting process. Eventually it does set and come off but that takes three years worth of 43 degree C summers.

holy macaroney!
 

www.de-interlaced.net/mini35

Check the bottom of the page.. just updated (2004-08-06)
Guys, you've got to help me know ;)

- Cheers
Eric

Just sand the inside of the pvc, It will eliminate the reflections. It works best with black pvc, but it should take care of white too.

1. Krylon makes spraypaint for plastics. So far I couldn't find a flat black (just gloss), but I suppose you could have a go with fine sandpaper after painting, to dull the finish.
2. I've used a cheapo flat black paint with no peeling. The trick was to use plastic primer first. That stuff is sold in automotive stores, it's used to prime bumpers and other plastic parts before painting. I think it is called 'adhesion promoter' or something like that. I'll give the exact name if I find the damn can...

I can't find black PVC to save my life -- any suggestions? I've called the largest plumbing supply shops in both Brooklyn and Manhattan and only one of the ten or so shops had a piece (female) of 2" PVC coupling, and a few lengths of the pipe. Everyone else suggested I look for "poly pipe," meant for sprinkler systems, though it is somewhat flexible and the coupling is pressure-fitted, not screw-on.

The Krylon paint seems available only in a glossy finish, at least wherever I've called or seen it.

- jim

anyone know where to get 5micron grit? jim, the gotgrit site has not processed my order since august 4th. so i need to find somewhere else that sells cheap AO

If it's only been since Aug 4th, I'd chill out and write them an email. It took about a week for my order to be processed, then a few additional days to arrive. They seem like good people -- just drop them a note and see what's what before cancelling.

- jim

well i already cancelled the order. what about the site you listed in your instructions? whats so bad about them? or where else can i get the 5micron AO?

I had to pull my sample videos of my GG orbiter working at HD 720P resolution, because I only get 5 gig a month transfer. About 150 people saw the demo. I can email a link if someone needs to see it for more than curiosity reasons, the video was 24 megabytes.

Am I the only one that actually posted some demo video to show the DOF working? I'm not talking about web quality video, I'm talking 8 megabit/sec full resolution, with a slow pan to show the grain not showing up as a fixed pattern.

Any other demo stuff, or was I the only one to post video?

Maybe I missed a post, there has to be over 1000 posts on various attempts! "where's the beef?"

Thanks!
-Les

Worldwide there are probably a whole slew of suppliers scratching their heads and asking themselves, what's going on with this sudden rush of small orders for 5 micron AO grit. Maybe Gotgrit is having to buy some more in. Lets hope they don't get stuck with a whole lot of it once the stampede dies down.

Regarding demo vision. Does vision of a spinner count. If so there's one on www.dvinfo.net/media/hart. (It's got sound too.) It doesn't stream and has to be downloaded.