I'll team up with any XL1 / XL1S owners on this as well.

I'm still not 100% sure on the whole process and procedure so I'm holding off ordering the alum. oxide.

Can you post your sample video again?
 

Sorry, I didn't have the chance to view your sample video.
Would appreciate it if you can post it again.

Frank, where did you order the aluminum oxide

Hi all (first post :))

I've been watching the developments with excitement!

As an XL1 user myself I've begun work on a static groundglass mini35 homebrew system. As demonstrated by so many with successful agus35 and similar implementations (and now Alain's static GG success) the most difficult part of a system for the XL1/XL1s is the relay lens and hopefully it's smooth sailing from that point onward (essentially an SLR body arrangement with finer groundglass).

I have designed a relay lens that should get our 36x24 35mm filmback size down onto a 4.8x3.6 CCD with suitable backfocus distance and object distance from the front element. I've ordered the lenses and should be getting them soon, if it's successful I'll share my design and findings with everyone.

(Check out LINOS Lens design software (free!!) at http://www.winlens.de)

I don't expect stunning quality, but hopefully my lens should work (anything else is a bonus! :)) and made with cheap surplus singlets and achromats from surplusshed it's a cheap and easy start. (If it works maybe I can get a thread of my own! :D)

Happy development!

Adam

Woah!
 

Phew! It's taken me half a day to read through all posts on the Agus, the other static adaptor and now this one. I'm not keen on messing around with motors, so Alain your adaptor seems to be the one I am going to try!

I was thinking I may try inverting the image with another lens. I know there will be reduced light, but it will be interesting to see how much can be gained back with post production levels tweaking. Will that much light really be lost? Many times when I shoot in daylight I have to use an ND, or even two ND filters anyway to avoid whites being blown out. If I was shooting inside a house etc I would normally use extra lights anyway. So using an extra lens to invert the image before it hits the ground glass might be useful in this type of situation to avoid having to flip in post. I was also thinking of mounting my Optex 16:9 adaptor on the front of the SLR lens via a step down ring as I will only want to shoot anamorphic with such a system.

Am I mad? Or is there a better way to do anamorphic with these systems?

Simon
 

The problem is you canot only use a lens ,you need a pentaprism.

http://www.zygo.com/appnotes/zms0017/zms0017.pdf

ALDU 35 Video and Pictures
 

Posted Here:

http://www.moorefilms.com/aldu35.htm

Taylor Moore
 

Thank you Taylor
Now Image are available here
for Aldu35

http://www.moorefilms.com/aldu35.htm



Alain
http://www.kheops-tech.com/~ad3d/

Noah: I ordered my aluminum oxide from Scientific Instrument Services, Inc
(http://www.sisweb.com/ms/sis/alumoxid.htm)


There's also another place called Ted Pella, Inc
(http://www.tedpella.com/material_html/grind.htm)


I went with SIS because they had the option to order a small (4oz) bottle. ($10.50 each)

Thanks, but the problem is that Scientific Intrument Services, Inc only sells 600 grit and the other place, Ted Pella, Inc only sells in larger, unnecesarry quantities and they don't sell in the larger 120 or so grit

Noah: That's true. I asked the representative at SIS over the phone, and they only have 600 grit. I'm hoping to just use 600 grit, instead of using bigger sizes and moving down. I know this will be a lot of extra grinding, but I'm willing to give it a try.

If I need to, I'll get a 1lb container of 400 or 320 from Ted Pella.

Alluminium oxid
 

Try here this is where I buy it.

http://www.microid.com/maison.htm

I can't imagine you canot find this in New-York.

Alain: It appears that your device is fixed to work with that specific 35mm lens. Have you thought about building one that is adjustable, to accomodate lenses with different flange focal lengths?

Alain--

Couple of things:

Could you post a close-up detail pic of the finished GG or is it "stuck?"

Do you think a electric grinder would work?:

http://www.amazon.com/exec/obidos/tg...&s=hi&n=228013

If so, they have grinding wheel attachments for this tool that comes in the lower grit aluminum oxide the project calls for. Perhaps this would cut down on some of the labor??

Here's another place I found 120 and 240 grit Aluminum Oxide:

http://www.caswellplating.com/buffs/aws750.htm

It's brown though. Is there a difference between brown and white?

1 pound is $3.50. Cheapest I've seen by far.

Todd
 

I really don't know.
I haven't try this . The guy's at the telescope store tell me that the glass for microscope that need really precise grinding or for there photographique need are Hand made. Maybe you can start whit this for the first step but the first step is the shortest one,
forget about that for the rest, (I think) So your not gone a save time but I tell you again it's not that hard.

When I was at the store ,and the guy's explaine me how to do it ,I was a bit sceptic but when I start doing it I can't stop until it's done.

Alain

Todd
 

----Could you post a close-up detail pic of the finished GG----

http://www.kheops-tech.com/~ad3d/Aldu35.jpg

Heres a test chart for the optical quality of all of our mini35 designs. Any promising designs should be put to this test to know for sure that its working as well as it can.

It tests for:
1)chroma aberration
2)barrel distortion
3)how much grain is apparent from the ground glass

How does it work?

Step 1: Print out the picture of the test chart on high quality glossy photo paper at 300dpi. You'll find a link at:
http://www.cinematographerreels.com/mini35info.htm

Step 2: Measure the image after it prints out. It should measure 24mm x 18mm.

Step 3: Videotape the image with only the diopter lens your using in front of your camera (diopters are also known as macros, closeup filters, achromats and apochromats) and make sure its in focus and that you are filling the viewfinder edge to edge with the image.

Step 4: Post a frame grab from your video here at full resolution (720x480). If you have straight lines in your frame grab and no color blurring then your mini35 system has pasted the test.

Now if you want to check for how much grain can be seen in your ground glass repeat the first 4 steps with your mini35 system put all together including your 35mm lens.

These tests will check, with precision, everything but resolution. You'll need to shoot a professional resolution chart for that. Post that too if you have frame grabs.

Link to mini35 test chart:
http://www.cinematographerreels.com/mini35info.htm

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801
www.CinematographerReels.com
BErskine@CinematographerReels.com

Any reason why the diffusers previously linked to won't work for this project? Aren't they just pre-ground glass?

Here's what I'm talking about...

Is it true that the grind, or frost, needs to measure in at 3 microns?

- jim

flipping the image aldu35
 

http://www.partsexpress.com/pe/showd...ID=16106&DID=7

hi everyone wonder If this might be of help .
alain ...that is the most beautiful ground glass I have seen.
my test with the glass etching paste seems to cause what
look like pit,s and alain do you have a method for protecting the other side of the glass when you are grinding it. thanks for all the great photos

http://www.bealecorner.com/trv900/re...x.html#EIA1956

This chart which has been recommended before in these forums can help you gauge the lines of resolution that your system can resolve.

I've got another ground glass solution
 

I think I've stumbled upon another way to get high quality extremely fine ground glass. Use the stuff out of a hand held photographic slide viewer! I took a photo of mine at the link below.

http://uk.geocities.com/brian.wyndham@btinternet.com/index.htm

I've got a spare piece somewhere so I'm going to try basing my Aldu35 around this. Sorry if the photo is a bit poor as I'm still at the 'mess around with things roughly placed on a table' stage! But I tried the camera behind it and it seems to be a pretty sharp image. Now I just have to work out what kind of macro attachment I'm going to use (it's for an XM1). The Hoya combinations seem to be the best bet judging from what you guys have said yeah?

I'm really hyped for this!

simon, is the slide viewer GG glass or plastic?

http://www.knightoptical.co.uk/acata...ticscreens.htm

Just looking at that it states.

"These Plastic Screens have still greater diffusion than ground glass types, allowing an image to be back-projected on a large screen without `hot spot’, and have a grey tint to minimise reflection of ambient and scattered light"

Would that be ideal for GG?

Richard Mellor
 

Put some scocth-tape on it to protect the other side.

for the monitor is the resolution good enought?

Alain

John, yes, I the screen is plastic.

I am also trying an inversion technique using mirrors (I tried a mock up with some mirrors that were lying around and it works fine as far as getting the image the right way up is concerned. Because it's done with mirrors the left to right thing isn't an issue by the time the image arrives at the camera. The image comes out left to right correct). The setup would be more bulky than Alains original design, but I seriously want to look at a correct image in the camera viewfinder rather than invert in post.

The pentaprism idea will get you an image that is the right way up but not correct left to right if I worked it out correctly.

Stewart--

Sounds like the plastic diffusers from Knight optical fit the project needs to a tee. Any idea the prices of these? Maybe one of us should buy one to test and report the results.

It says that they can custom make them too, which is nice.

The price is on this page (from 9 pounds for 3mm thickness):
http://www.knightoptical.co.uk/acatalog/DiffusersPlasticscreensSquares.htm

I wonder why they're talking about gain, do they have a Fresnel on the incident surface?

Also, has anyone considered if diffusion screens from rear projection TVs could be used? They get scratched so often, I imagine I could beg at a local TV repair shop for a couple of throw-aways, find one where the center part isn't scratched, and just cut to size.

Test Chart
 

Here is the test that I did , sugested by Brett Erskine.

I have change the lens from the optex magnifier for a lens that I took from a old super8 camera that is mutch better and the size is the same .Whit the test chart I notice immediatly how much distortion I get from this magnifier,So I chane it

There is a bit of lost of sharpnes and in light .this is shot whit a normal 60W light.



http://www.kheops-tech.com/~ad3d/test-chart.gif

Not too bad. You'll need to fill the whole frame next time you shoot the grid chart. If you can't you wont beable to use 35mm cine lenses correctly. But it looks like your already just close enough for regular 35mm still lenses so no huge loss.

I noticed it was alittle soft and had some chroma distortion starting to happen as you go out towards the outside of the frame. Sounds like your using a single element magnifier. Swap it out for a two element lens like a achromat (diopter) or for the best possible results a three element lens called a apochromat (triplet). Make sure it has enough magnification power and retest with the chart. Should make your setup work perfectly.

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801
www.CinematographerReels.com
BErskine@CinematographerReels.com

I have just ordered 100x100 of the 3mm thick acrylic diffuser from knightoptical.co.uk

Will report back when I receive it, could be up to 7 days.

Brett Erskine
 

I talk to guy's that is an optic specialiste this evening and he say the same ting about the diopter,I need three lens for better result

I alway's thoug that one element is better than three in optic.
But no.

So I get back to work.

Alain

Alain make sure you dont just stack three of the same elements you are using right now. That wont work. Your going to need something called a achromat. Its at least two elements that are optically designed to work together to correct this problem. They are perminately cemented together when you buy them and are often housed in filter rings.

As far as having THREE elements its the same idea as I just mention. But in this case there is one more element that is cemented together with the other two. With this arrangement your sure to correct ANY possible barrel or chroma aberration. But there is currently conflicting information on the usefulness of the third element in the system as some say it only corrects for the UV part of the color spectrum while others say it also helps correct parts of the visible spectrum. Specifically the color violet.

Btw I think you finally convinced me that your ground glass is up to par with that last image you sent me of the resolution chart you shot. I didnt see any grain. Now lets all hope that the softness seen in that image will be corrected with the information Im giving here. Good luck everyone.

Brett Erskine
Director of Photography
Premiere Visions
1761 W. La Palma Ave., Suite #302
Anaheim, CA 92801
www.CinematographerReels.com
BErskine@CinematographerReels.com

P.S. THREE element corrective optics like I described are called APOchromat. Microscopes use them and they go way past 10X power but are too small to use for our purpose. Its a proven solution. We just need to find them in a bigger physical size. 58+mm I would guess.

Hi Brett,
AFAIK Achromat or Apochromat lenses are designed to correct chromatic abberations only and do not correct for geometric distortions such as pincushion/barrel.

Update new lens
 

There is some small problem here, but everything are only tape together

It's not perfectly aling


http://www.kheops-tech.com/~ad3d/test-chart2.gif

Alain

Check this link out if you're in the states:

http://www.poc.com/lsd/default.asp

This, too:

http://www.poc.com/lsd/default.asp?page=overview&sub=dds

- jim

I just saw the test charts, the results are really quite amazing, but is it me, or in the last test i see a little grain ? is that because of the gif compression ?

Also, you can really fix the image distorsion if you use a fresnel lens, as now you only magnify, you need to correct that magnified image so the distorsion is minimal (Just like Daniel Adapter, which proves to work great with a 1chip 380k effective TRV18 camera )

We are now going to make a new system from this basic, but with the flipped image, i will try to get something done for next week.

Congrats man, and you are a great pionner and i admire your intuition and creativity to go a step ahead and come with great results.

Alain, fantastic work man, please keep it up.

My observations of the latest test charts are that, while the adapter slightly softens the image (probably due to it not being perfectly in focus on the GG) there is actually GREATER resolution being captured from the Aldu35 adaptor image than the image with stock lens. I'm not sure how that's possible but that's my read of the chart results...

By the way, even if that is slight grain and not .gif compression, I still think that image quality is MORE than acceptable for the kind of application we're talking about (guerilla indie film making!) Sure, no grain is better than a tiny bit, but I'd HAPPILY shoot with a tiny bit of grain if it meant wide DOF and a simple-to-make adaptor.

paulb

Alain Im very impressed with your results. What did you change on your adapter set up since your first test chart? The test were so good I just want to make sure----did you shoot the chroma aberration test chart with only your "magnifing" lens or was that frame grab shot with the whole mini35 setup put together?

Same question for the resolution charts.

Looks like Alain may have done it. Now a even harder challenge will be to get a similar system to work on the DVX. With its longer minimum focus and large lens diameter its going to be a bit harder.