320 by 240 is a no go.
 

Yes, a spinner version *would* count!
But that video quality was, frankly, krap. ( the 9.5 meg MOV )
Common guys, we can't see anything at 320 by 240 pixel size!
This is what I'm talking about. Somebody must have posted something at quality size. Did I miss it?

To reiterate: The demo needs to be FULL SIZE.
Bit rate of at least 7 megbit/sec for a modern codec.
It should have some objects out of focus. ( helps see grain)
There should be a slow pan to see if there is fixed pattern grain.
Stills are completely useless to demonstrate a working system that has no grain or pulsing.

-Les

<<<-- Originally posted by Bob Hart :
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. -->>>

Les-
Whats your actual target size on your GG for your adapter?

Brett,
As I mentioned in the post where I had the links, it was about 30mm across. That made my 50mm lens act a bit longer, maybe 65mm.
The whole setup was temporary, the camera wasn't even held down with anything other than gravity! I was positioning it trying to get the biggest target in the viewfinder and still allowing focus to hold on the GG. I used auto focus on the GG but I checked that it could get there by switching to manual and seeing if I had some 'headroom' with the manual focus, then switching it back to auto. Seemed to work.

Did you look at the video? Thoughts?
I got only one comment. I figure people are either depressed looking at the HD like that and just clammed up, or they just don't care about the whole DOF thing that much any more. Or they are busy with milk and balloons and office supplies making one of these !

-Cheers
-Les


<<<-- Originally posted by Brett Erskine : Les-
Whats your actual target size on your GG for your adapter? -->>>

The link I've got posted on the tutorial is for 1000 grit grey aluminum oxide. Sitting it next to the WAO 5, the difference is striking -- the former feels close to table salt, the latter to flour.

It's been my experience that, provided you grind properly with WAO5, it's about ten minutes of grinding to get a uniform, scratch-free surface. The grey 1000 grit leaves uneven scratches behind, nevermind the fact that the coarser grind of it makes to GG more opaque than it should be -- so you loose more light.

The keys to a good grind:

1) Grind on a flat, level surface -- I used a formica tabletop.

2) Grind using a piece of glass placed over the GG, and not the other way around -- this distributes pressure evenly, reducing the likelihood of sratches.

3) Where WAO is concerned, "less is more" -- use just a pinch of it, and about three times its volume in water. When you place the grinding glass over the filter, the water should spread evenly and soak the WAO thoroughly -- dry patches of WAO mean you're likely going to gauge scratches into your GG surface. You can even give the process a head-start by waiting to allow the water to soak into the WAO before applying the grinding glass.

4) Remember this line from 'Ronin' -- if there is any doubt, there is no doubt. Think you might have dry WAO? Don't risk grinding. Wash the surface and re-apply. Think you might scratch the wrong side of your GG? Mark the glass at the edge.

Les,

As for video, I've uploaded full res footage with my 1000 grit GG, and have since pulled it. I'm waiting for the opportune time to finish the latest adapter -- have already finished the WAO5 GG, today picking up more PVC, some plastic dye or primer if I can find it -- and should have new and improved footage in about week.

- jim

Good to see you're still around, Brett. I owe you an email but as you can see I'm busy here, typing away :D

Went out looking for black PVC today and came away with black versions of the female half of the 2" PVC coupling. The guy at the shop says he could order male halves, though I'd have to order them by the box. They're about 75 cents each piece, though I don't plan on needing a whole box of them so for now I'm just going to sand down and color the white male halves I have around. I plan on sanding, priming and painting it, but placing electrical tape on the interior rim of the adapter where it slides over the Century Optics macro -- this way, there's no chance of paint chipping.

To that end, I picked up the plastic paint primer mentioned above -- it's official name is "Bond Aid -- Paint Adhesion Promoter," from a company called Klean-Strip, the "surface prep specialists." I got it at an Auto Zone for about $6 -- the can's 12oz and features a gold, black and white color scheme, with a picture of a car's front-end on one side. Pics of this will be in my new tutorial.

On a related up note, the female halves I purchased have a uniformly smooth outer surface, as do the male halves I picked up, so there's a step of filing eliminated. The rim of the black PVC reads like this:

2867 ABS-1 c 2 NSF-dwv UPC MADE IN USA


- jim

hey jim, if i paypal you some money, can you send some AO to me? let me know my email is vold@adelphia.net

Can't do PayPal at the moment -- I've just moved and can't for the life of me get a bank account.

First, I needed a utility bill but I only had photo ID and SS card. Then I got a util bill, but apparently a cell phone bill doesn't qualify. Then I got a water bill, plus photo ID, but on the one I'm "Jim Lafferty," and the other, "James." They claim the discrepancy makes it impossible to open an account! :(

- jim

then out of the kindness of your heart, you think you can send me enough AO to make ground glass? ill mail you back some cash. lmk if you can and ill give you my address.

Les.

If you send me a postal address on the email via the profile menu on the page here, I can send you a DVD+R disk via the snail with a .avi file on it.

<<<-- Originally posted by Les Dit : 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.
-Les -->>>


Hi Les, I'm planning on building something based on your general idea. I'd really like to see your video. You can email me via my profile here.

I've got a couple questions for you though. Are you inverting/reversing the image or doing that in post? Also, did you use any extra lenses between the lens and your vibrating GG?

Thanks Jim. Something to keep in mind when going for that ultra fine grain texture for your GG. When you grind your gg ultra smooth with AO in order to remove as much grain as possible there is a point where the grain gets so fine that a new set of problems begin to increase.

1)Increase in the diffuse quality of the image

2)Increase in light loss

This is one of the reasons why I decided to make a new adapter that has a moving GG.

In order to get over the two above problems the "ideal" static gg would not be made with AO but be a series of random microscopic pits. Each pit could be a miniture cylinder with refective interior sides and a textured glass bottom. This design would be the ultimate in contrast in grainlessness. Each one of these pits would have to be smaller than the CCD's pixel and randomly layout right next to eachother in order to avoid a morray effect. Millions of these pits would make up a small focusing screen that would measure not much larger than 40mm across. These pits could be cut by a laser enscriber but how your going to get that mirror finish is beyond me. Perhaps you could go without. Remember laser enscribers are able to etch company logos with perfect accuracy on the edge of a diamonds surface so small that a 100X microscope is needed to see it. There is little doubt in my mind that this would be the "ideal" focusing screen but then again what is ideal and what is within our means are often two things. Just though I'd throw it out there for anyone with the resources.

-Brett Erskine

Bob, I mailed you , thanks!

Joel: As soon as I sort out my server, I'll mail a link. A Gaggle of lurkers wiped out my free 5 gig/mo limit on that server!

-Les

How about this for a ground glass and inverting the image

http://porterscamerastore.com/Merchant2/merchant.mv?Screen=PROD&Product_Code=19-0116&Category_Code=V1D

I've always wanted to see how good that screen looked. Just so you know while it will beable to mirror the image left/right back to normal it will not flip the image right side up again. Someone buy one and post a high res video.

I have one and got it to transfer 8mm to DV.
I will not use it again even for 8mm/16mm transfer.
The grain is LARGE, glass type bubbles on the backside and shows up as if it is dirty.

yesterday i dismounted another LCD screen from a laptop and found (no surprises) the usual set of thin sheet of plastic.
two are kind of transparent stuff that are not transparent (weird), like fresnel. no use for us but two others are frosted plastic , one half transparent , the other one totally opaque.
both have a finer grain than the previous sheets i found in other LCDs. I think they would not fit for static gg (grain is close from what you get from an average gg), but would have no match when used for orbital gg. The sheet is very thin and a small part of it will have almost zero weight, so no inertia to compensate.
Additionally you can just cut it at any size or shape with a simple cutter (mounted in a 35mm slide frame ?)
I will make some test and load picture if i got time (playing with HD now ;-) ).

please keep me posted on the tests with the LCD stuff!

If you Google around a bit for technical papers to explaine how these different sheets in a LCD system work). Try 3M, go to sid.org and try the manufacturers links (Sharp, and probably Casio, have papers, but it is notoriously hard to track them down as Sharp is spread accross so many websites, and are hard to search (I find Phillips, worse they should look at getting their UK programmers to do the world headquaters sites)).

Go to google, lookup www.handheld2000.org and use their cache feature and look through for links to LCD and display stuff, and the bookmark file posted their (has some links to LCD papers).

Look through my posts on the two main adaptor threads and three original home cinema camera threads, I might have posted some links to some papers there.

Some of this tech would be helpful, but feature size will depend on resolution, and has to match the format being used (35mm MF), so ordering directly from the factory might be a better move.

Thanks

Wayne.

New page of full res pics and footage from my GL1 adapter here.

This footage is straight from capture with no cleaning, color correction, cropping, etc. All shots were taken more or less at f 2.0, 1/250th shutter, no gain. Time of day was late afternoon, 3-4pm.

As mentioned before, I need to update the tutorial's text to reflect new lessons learned, and will do so soon(ish).

And yes, Les, Brett, et al -- I see the grain and don't care :P :D Looks good enough for me (note: there's no blooming and I'm not using a condensor!)

- jim

- Jim

It looks great. I've reached the point where I no longer care about the grain either. Kinda charmy in a way. And you can do some post production to get rid of it.. a good way is too put a little noise on the footage wich will distract your eyes from seeing the static grain, and I also duplicate the footage and have one layer "gaussian blured to strength around 4-6" and with opacity around 20% that takes away the static grain and even gives the film a more film-looking feel.

great work. i'm downloading the pans and racks raw msdv ntsc files now :)

Jim. A quick question.


Is the GG 3 Micron?

What size image frame were you taking off the GG?

Oh well it was two questions.


As for static grain, I could live with what you have there also. I think that provided there are no larger spot defects on the GG texture to spoil the even-ness, it is an aesthetic not unlike the use of different papers or canvasses in drawn and painted artwork.

As for the larger defects, I seem to recall stains on cinema projection screens from misguided cleaning attempts and the odd spider's web or two.
Can larger video projections systems resolve the grain??

Eric,

Thanks for the post advice. I'll look into your suggestions.

Bob,

It's WAO5 from gotgrit.com. If you know of a reputable 3 micron distributor, I'd like to know of it, too -- while I'm content with the image as is, I wouldn't mind trying an even finer grain. This GG took me about a half hour to produce -- if you do it right the first time, and avoid deep scratches, grinding is pretty much a headache-free affair -- so another half hour wouldn't kill me.

As for the image size, I don't know that answer. All I do is lock my Nikon lens in on an infinite focal length, point the camera at an evenly lit surface with hard edges (black text on a white background is good), and adjust the zoom and focus ring manually on the GL1. I get it just out of focus and then tap the telephoto rocker back until it get's everything sharp again -- then I check the edges for blooming and, once I've got it set right, slide the camera into 'lock' mode. Then I'm ready to shoot.

- jim

Jim.

Thanks for the info.

I'm using 5 micron. Because I was using a machine I was able to work the mix to exhaustion to get a slightly finer finish but found it became too transparent with hot spotting and ghosting (too much aerial image coming through the projected image).

I returned the disk to a new 5 micron mix and stopped it before it began to fine up. I tried a backpolish on wool felt and Cerium Oxide for 10 minutes which seemed to improve light transmissability a little without losing the opacity.

Instead of a glass polishing surface I tried several metals and found a machined face on flowcast bronze worked best and did not dig scratches into the glass.

I was told cast iron is okay but there must be a special grade because there were very many bad scratches from the piece I used.

Aluminium just didn't work well at all, too much metal and sticking.


I am shooting the 18mm x 24mm image frame which makes the grain larger. The relay lens set I use does not permit a larger projected frame.

small bright spots
 

Hey guys!

I've been grinding a GG for a static adapter with 5 micron, and everything has been going great, until yesterday, when I discovered that my camera picked up very small, white spots when I was aiming at something bright ( like a spotlight, or a window in daytime ).

My guess is, that the light makes the grain shine up, in a way .. Am I right?

Is there any cure for this?

Try a ND or polarizer on your 35mm lens?

- jim

after further experimenting, I found that it was the other side of my condenser that was causing it .. any bright light would make the smallest particle visible, or fingerprint

I'm going to try rearrange my two condenser lenses like this
(the second condenser is the one with the GG .. )

SLR Lens - [)(] - Camera

That way, no dirt or fingerprint will shine up like it did in my other arrangement below ..

SLR Lens - (][) - Camera

Am I missing something? When trying that new arrangement, I can't see any optical distortion, so I guess it's working .. ?

tja martin!

just wanted to let you know that i've ordered 2 pcx-lenses, a fresnel lens and a GG in plastic. i will let you know how the fresnel is.. and if the GG is any good. i can't wait til i get these stuff. i hope the fresnel lens is good. that's the lens they use on real GG to get rid of vignetting (you know the guy on voodoofilm who shot through his F4, that viewfinder was a GG with fresnel-lenses on both sides).

i'll let you know later this week.
but hey... hows the GG's coming? you don't feel scanning a GG in high res, like 1000x1000 or something? would be great.

---------
your condenser lens experimentation... why would fingerprints be more visible the way you had it before?

TO EVERYBODY-
is there any software wich will show you how light goes through lenses... that way we could see the difference in (| |) and |) |( must be some software out there... where you're able to see the "light curve"

heey eric!

Sounds great! Keep me posted on your progress with the plastic GG ..

My GG is doing great! .. As I said before, I've been grinding one of my condensers, and now after 4 hours + of grinding, I don't think it'll get any better.

Today I tried my theory .. I flipped the condenser, and yes, those irritating bright dots disappeared, BUT .. instead I got some wonderful vignetting .. ! jippi! .. I should have foreseen this .. : /

So, when undoing everything I just, the backlid of my Canon FD lens poped out along with springs and other delicate stuff .. i must be cursed, or something ..

So, back to the first issue .. I guess I'll need some ND filters, and really watch the lighting when shooting, cause there is no way in *beep* I can keep the back of my condenser that clean .. how are guys dealing with this? ..

Mount your condensers in filter rings, clean them perfectly then sandwich them bewteen two Skylight filters.

Make sure the gap between skylight filters and the GG is far enough to put any dust they get on them way out of focus.

2nd option: Make a vibrating adapter.

- Martin

Did you grind a condenser lens on the flat side!?!

yes, eric, I sure did! :)

anyway, here is a picture of what I am dealing with !

http://www.martin.incmplete.com/mini35/dirt2.bmp

and ..

http://www.martin.incmplete.com/mini35/dirt4.bmp

now, it's really, really hard to see these things in a picture , but look at the bright spotlight to the right .. around it, there are small white particles ..

Actually , Brett .. I am considering building me a oscillating adapter .. I was thinking about making it squareish, with 4 shafts and one motor .. don't know if it'll work, though ..

"Actually , Brett .. I am considering building me a oscillating adapter .. I was thinking about making it squareish, with 4 shafts and one motor .. don't know if it'll work, though .. "

Yeah that will work...at least it worked with mine.

-Brett Erskine

<<<-- Originally posted by Brett Erskine : Yeah that will work...at least it worked with mine.

-Brett Erskine -->>>


Hey Brett... do you have any pictures of the rig and result? I definately want to see it.

And Frank Ladner..where are you?
Hows the microcrystalline wax coming?

Eric: Hey! I still read the forums almost daily, but I haven't had time to work on the adapter at home due to side-jobs. You know how that goes. I haven't given up on the project, though.

Im in the same boat as Frank. I'll post it when its all done and well tested.

LOL, I leave for 6 months from the site and I see you all are having the same issues. Not a whole lot of forward movement in the last 800 posts. Oh well...have fun building!

John, I posted some examples of mine device working at HD resolution. Still not perfect, but there is no grain.
I don't need the artsy-fartsy grain effect.
Email me if you would like a link to the 25 megabyte full res test clip, it's only a few seconds long.
-Les


<<<-- Originally posted by John Gaspain : LOL, I leave for 6 months from the site and I see you all are having the same issues. Not a whole lot of forward movement in the last 800 posts. Oh well...have fun building! -->>>

i want to see it!
mail to: eric-ohmanATtelia.com

i can host it too if you want... i have 300mb.

<<<-- Originally posted by Les Dit : John, I posted some examples of mine device working at HD resolution. Still not perfect, but there is no grain.
I don't need the artsy-fartsy grain effect.
Email me if you would like a link to the 25 megabyte full res test clip, it's only a few seconds long.
-Les


<<<-- Originally posted by John Gaspain : LOL, I leave for 6 months from the site and I see you all are having the same issues. Not a whole lot of forward movement in the last 800 posts. Oh well...have fun building! -->>> -->>>

cool! I'll search your name for posts to see what you did.

thx

Les,

Could you send me a link to your footage? I'm at raeshao@comcast DOT net. Thanks a lot!