frosted cd
 

i got mine frosted cd from guy who is selling lot of cds.

he can't answer me exactly what brand it is, definitelly NOT TDK!
a while ago - when i had a closer look i noticed that surface is VERY similar to frosted foil used to cover windows etc. in offices, homes... (you know - already prepared, with transparent glue on it, stickers type)
i just compared it now with a foil and it looks really close. i do not know about the picture quality, but will check that tonight when i'm finising "my" agus 35.

all the best,

"keep agusing!!!"

filip

This may be a stupid question...

But how are people connecting wires? ie the motor to batteries? I've tried duct and electrical tape and it doesn't seem to hold that good?

I think solder would be the matrial of choice

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

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

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

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

I'd say the new footage that Agus posted is very acceptable for what I want, but I'm more interested in a movie look than high detail. Even if it has some grain (which I can't spot anyway), it adds to the effect.

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 ?

I think don is also right but I think centering the disc could be a problem with glass... The cd disc is easy with a cd motor

BTW -

DON - I worked as a PA on your short film 2 years ago... did you ever finish it? It was a surprise to see you on this thread...

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.

agus - I think people would be satisfied in a commercial version if you could find either:

A. an output from the cameras RCA's that will flip the image normal for an external monitor/lcd

B. If you include an LCD that will flip everything.

I like the idea of the prism but I think it will cause too many problems plus it will just be one more thing the light must go through and will bring the light levels down yet again.

I don't think most people have a problem with flipping in post... the problem is to see everything as it is (right side up) while filming.

mmm

who else thinks about this ? that would be easier and cheaper, just to buy a LCD monitor that flips it than the prism.

Agus, are those your sons or your nephews? They seem like good kids. You should name your device after them to reward them for tolerating your chasing them around with your device, which I am sure looks a little scary to them. hehe

Just curious if you could find a way to control the exposure more - so that you are not so overexposed in the white areas of the frame? It would be cool to see a nice flat, balanced exposure.

Is that sound I hear being made by your device? Is there a way you could deaden that sound? Reminds me of an old class at MIT, where the engineering students were given a Braun coffee bean grinder and the goal was to see who could figure out the best way to make the grinder perform as silently as possible. One solution was to deaden the walls of the coffee bean grinder with neoprene and to use a motor which was slightly over-rated for the task of grinding coffee beans. They lowered the voltage to that motor, so that it ran at only the torque needed to grind the beans and it was indeed a bit quieter. I would say that plastic shell of your device is resonating and somewhat amplifying the sound of the motor. Perhaps gluing a thin piece of neoprene inside the walls of your device (or around the motor?) would help mask the sound.

- don

yeah those are my newphies they are twins. :)

The problem really is that the mic of the TRV is less than 3 inches from the motor, so it is silent but the mic is too close. it can be solve using an external mic with no trouble. about the exposure, my bad i was so excited using the device that i didnt set it manually. but well :) i am so haappy that the optics are working well, and the image is not deformed like my first versions, and also there is no vigneting.

Don what do you think about a commercial version ? is flipping the image critical ?

>>>>>>>Don what do you think about a commercial version ? is flipping the image critical ?

Absolutely! Anything less is a compromise. You want as few compromises as possible. You have to define who your target market is... hopefully you set your sights higher than just the people who only want to spend $60.

- don

I think, and I could be the minority but I wouldn't think I am... if it is a loss of quality or light steps flipping the image is not needed if you could somehow see the image right side up while you are shooting (ie flipped on a monitor or lcd).

I would rather that then lose quality.

Are you using a fresnel lens or macro between your GG and the camera Agus?

Yeah, a magnifying glass actually it is very powerfull i took it off froma wide conversion lens (VCL-0630 S)

Peter i still havent test using Glass, i am sure i will loose lest light with it than with a plastic cd, also the pentaprism or dove prism should be high quality to work...

I've got a B+W +10 diopter on order for my GL2. Can't wait to test it out.

I have figured out a static (no moving parts) solution. The test is very promising. I'm still waiting for parts to complete the whole thing. Once complete, I'll have an adapter which:

1. produce upright image
2. smaller (6x10 cm)
3. higher image quality and brighter.

The downside is that the complete cost to produce such adapter will cost a few hundred, might cost more depending on the quality of the coating and glass.

http://f2.pg.photos.yahoo.com/ph/lou....dnm=model.jpg

Vendi35 !!!

Sounds interesting. No moving parts though? How is the image plane resolved? Onto what?

Bring it on.

- don

inverting ideas
 

<<<-- Originally posted by Peter Sciretta : I think, and I could be the minority but I wouldn't think I am... if it is a loss of quality or light steps flipping the image is not needed if you could somehow see the image right side up while you are shooting (ie flipped on a monitor or lcd).

I would rather that then lose quality. -->>>

peter,
(and others, of course)

i think that there is a place where you can put a prism for inverting!
if the small prism (DOVE PRISM) is mounted as kind of EXPANDER of normal viewfinder (between your eye and a viewfinder) - you will NOT change a picture (quality) at all, you will se everything in a proper way - but you will of course need to flip recorded image after the shooting.
considering small monitor already with the cameras - i think that VERY simple device can be added to commercial version of agus35 - small mirror laying down on one side of "LCD chimney" - so if you are turning your camera monitor bit down - you will look at that mirror which turns everything upside down. so the image foer the viewer will be again proper one.
does this make a sense?

For people who don't use the viewfinder as much as a lcd or crt monitor this viewfinder idea is not good. If you're going to do any handheld work we'll need to see an lcd right side up.

As for the mirror LCD idea, I implimented this with my unit weeks ago... this still has the BIG problem that everything is still flipped horrizontally.

Vendible Book,
Sounds good ...what type of camera are you using??
Looking forward to pix

The limiting factor of the current method (mini35) is the requirement of moving the GG. P+S was able to create something fairly small because they probably machined the parts as small as possible. The sole purpose of the rotating/vibrating GG is to reduce the artifacts produced by the coarseness of the GG.

I have been testing a number of solutions, ground glass and other kind of materials to produce a diffusing surface that is very fine, so fine that it appears to be white to the camera. With such surface, you can project image on to it and there won't be any noticeable artifacts. The result is pretty close, but not yet there. I'll let you guys know how it goes.

<<<-- Originally posted by Peter Sciretta : As for the mirror LCD idea, I implimented this with my unit weeks ago... this still has the BIG problem that everything is still flipped horrizontally. -->>>


of course, peter - you are absolutelly right. i was too fast with that one.

mea culpa.

filip

This is a very rough test of the my static solution. I am still looking for method to improve the quality. Especially in terms of transmitting more light and to be able to "distribute" more light to the corners. Maybe a frensel lens would help.

http://f2.pg.briefcase.yahoo.com/bc/...=/35mm+adapter

Venible

If you use a screen that is diffuse enough, like the one i decribed to you, it should not need any fresnel, well from the tests i have read of it, it hasn't required one.

Zac

No Moving Parts
 

Hey, I tried to post this yesterday, but I may have found a way to not have to use a spinning CD. I had to scrap the spinning CD because of the size of my camcorder (which made it virtually impossible for me to have a spinning cd). The non moving method has no scratches, dust, etc. The image is bright too.

I used very thin, slightly diffused plastic and if i triple the layers it becomes diffused enough to create the projection. Worked for me. I was using other still pieces and the scratches from the sandpaper were just too noticeable. I knew there had to be an alternative. I'm not sure how it compares to the spinning CD, but it works for me.

Yeah, you need to zoom or magnify it. If you are zoomed in as far as possible, then you need to magnify it before you capture it. I have had problems with the vignetting, but that was due to my holes being off and not totally centered. I was able to zoom in a little more and that fixed the problem...this is just with the lens going straight into the camera without the frosted glass. Haven't got my hands on the sandpaper yet. Hope it works!

Hey Corey,
Can you post some pix?

Corey,

What is this plastic you are talking about? And, where did you pick it up...as stated, I am waiting for the frosted CD, frosted plastic, etc. to complete generation 2 of the Agus35. Let us know ASAP! Thanks in advance...

Clay

Canon FD Lens question
 

This may seem like a dumb question to some, but after some browsing, I couldn't find an answer.

On a canon FD lens, how do you open the iris? Does the lens have to be attached to a camera?

I turn the aperture adjustment ring and it clicks, but the iris doesn't budge. Do I have to hold one of the pins on the back of the lens and then turn it or what?

Here is a picture of the lens:
http://www.canonfd.com/lenswork/lenswork010.htm

Thanks in advance

Spass

Jeremiah (or is it "Spass"?),

Sounds like the silver locking ring collar on the back of the lens is locked into "lens detached" position.

If you are looking at the back of the FD lens:
1) Press down on the tiny Positioning Pin closest to the Red Dot on the outer back ring.
2) Move rear locking collar fully counter-clockwise.
3) Swing the rear "Automatic aperture lever to the right until it clicks into position.

You will now be able to open and close the iris by moving the iris control ring on the lens. Note that as you move the iris ring, the rear "Aperture signal lever" will move to a new position, depending on what you set the iris control ring to.

- don

Low Light Performance of Agus35 ???
 

I'm surprised that no one has yet asked that classic inevitable question: How does the Agus35 compare to the Vendi35 in terms of Low Light performace? >joke<

Well,,, I guess you could possibly mount a Lomo Night Vision scope to your adaptor,,, ;-)
http://www.opticsplanet.net/nightvision.html

- don

Don, that's a good one. Actually I think Agus's last video looks really good. However, it's an outdoor shooting, lighting is much more abundant in that case. I have yet to see anyone that can handle in door lighting well.

It should be noted that the video I shoot was shooting directly from the GG without any cover and was not modified or color corrected in anyway. I'm sure it will look brighter when everything is in a blackbox. But I'm not expecting dramatic improvement from this type of GG (hint, hint).

In fact I am wondering how good the mini35 is, considering there really isn't that much light passing through the lens. I don't believe there is any magic that somehow they can "squeeze" more light from how much there actually is. Again, it probably works well outdoor with bright sun light. I haven't seen any "bright" indoor shots on their web site (most are dark and smoky).

Having played with different kinds of real ground glass, I can tell you that the best/finest ground glass can only produce ok results in a static solution. However, there are other materials can do much better job, both transmitting more light and produce clearer image, but also cost a lot more. Let science do the magic, that's what I'm going to test next. I might even impress myself.

Regarding using ground glass/plastic/consumer products

All the materials above will work fine with a rotating/vibrating solution. The downside is they scatter too much light in every direction. They are not specially made for this video recording.

A static solution is even harder. Ground glass won't work, plastic CD won't work, any short of consumer product won't work. They all produce uneven illumination or visible noise.

I am only considering a static solution for myself, because it would be much more cumbersome to produce an upright image with the rotating/vibrating solution. The missing part right now is to find the best material for the projection. I might have found what I need. I'll know in a few days.

It's called...
 

Plastic Sheeting. It's real cheap. 3-4 layers should be enough. Works pretty good. It doesn't need to be rotated, because it's not all scratched up. I'm not sure how it compares to the CD though. I will see if I can get some photos or videos up later. I'm still having some vignetting issues.