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-   -   Aldu35 vs Agus35? (https://www.dvinfo.net/forum/alternative-imaging-methods/22528-aldu35-vs-agus35.html)

Lyndon Golanowski March 7th, 2004 03:16 PM

Aldu35 vs Agus35?
 
Are they both delivering the same quality of picture? So far it looks like the Agus has a better film look. Can anyone input on this?

Post any links to tutorials as well.

Giroud Francois March 7th, 2004 04:25 PM

fact is that moving part are the hell to move with correct alignement. Fixed GG or not seems not to be the biggest problem.
Vignetting is more annoying, turning the image upside down is another.
Fixed GG shows really good performance, so i do not think it worth to add the complexitiy of adding a motor and moving GG.
Movng GG probably doesn't add quality but could solve the problem of a messy GG.
Anyway if you need to move the GG there are probably more efficient way to do it (like using a roller bearing with a big internal diameter so you can glue the GG on it).
This will ensure perfect alignement easily and still small design.
Then you can make the GG rotate just with a friction wheel to the inner ring of the roller.
If you need easier way, you glue a bigger GG on the outer ring of the roller and fix it on the tube by three legs on the inner ring.
so you can put a simple plastic belt around the outer ring to rotate it.

Dino Reyes March 7th, 2004 09:51 PM

I think what the Agus does is gives the image a pulsing/throbbing feel that film gets as it runs through the gate. It's very subtle but they also call it film wobble. Film and imagery jump around-it gives the appearance that everything is alive. If you watch anything digital on a monitor, go up and put a pointer or a pen or finger to an image on the screen, like a corner or a window and it is always stuck in one place. That's full on pixel control, like your computer. That's digital. Now try that will any filmmed piece, everything; credits, people walking, still shots, etc... moves around. The Aldu is much more stable, as in heavy duty, (that could also be my construction ability to), something i am concerned about when i'm out shooting... but overall, they are both nice guys for their inspiration and contribution to this community. I would suggest building both to strengthen your learning of optics with dv.

-D

and as far as addressing "correct alignment" you can build a beautiful Agus35 using a CD player body and about only 4-5 inches of PVC pipe. Cut a 2 inch hole on one corner of the CD player (imagine using a shotgun and shooting a hole clean through to the other side) degut the thing and leave only the CD motor and battery box and connecting wires. Go to radio shack and pick up strong batteries and a small led light (to tell you if it's off or on). Pay a stain glass cutter to cut a perfect shaped CD out of glass (less than 1.7 mm thick) Sand to gg, pop that sucker on, throw on a cheap fresnel, rewire so all you do is slip in a battery to turn it on, glue together and you'll have a whisper quiet Agus35 "correctly aligned."

Brett Erskine March 7th, 2004 10:52 PM

Dino I know what you mean about how film always is moving but you wont get the same effect with the spining CD for two reasons:

1)The grain (if visable at all) will look like blur streaks. With film each frame has different but static grain.

2)The CD will not cause the image to shift like film. Instead all it can do to the image is put it in and out of focus slightly if the CD wobels*.

IF you wanted to add grain (the exact thing that film makers usually try to avoid) to video that would look and act the closest to what you see in film - it would be added in post. The ever so slight image shift could also be done there as well.

If you can get your GG to appear grainless without moving it - the only advantage to spining it would be to make sure that dust, hairs and dirt will never ruin one of your shots.

Lyndon Golanowski March 8th, 2004 02:19 PM

where can I find better measurements etc. to use.

i.e 30mm from lens is ground glass, 30 mm from ground glass is camera...anyone know??

Giroud Francois March 8th, 2004 02:43 PM

that is pretty easy but unfortunately due to the nature of the ingredients of the recipe, i think for instance nobody is using the same parts, so nobody use the same distances.
from the lense to the GG, you use the distance that was originally set in the camera from where you take the lens.
There are tables for this, but manual alignement to get proper focus is probably more accurate. you can screw together two filter frames to get the last ressource of adjusting the last angstrom by (un)screwing them if needed
from the GG to the condenser, the rule is: the shortest, the better. So just keep one milimeter.
from the condenser to the macro lens, well i think the best would be to say: from the GG to the macro lense and ignore the condenser. Mount your macro lense on the camera and try to find the distance where object are focused ok at a workable size. Additional zoom will probably be needed due to the fact that most of LCD screen or viewfinder do not show the full picture.

Bob Hart March 13th, 2004 08:22 PM

With an inconsistantly frosted rotating screen, there is also a motion film projection effect conferred by slightly varying intensity between frames as more transparent sections move through the image frame.

You can observe this to strobe across the screen if you crank the brightness and contrast to the extreme in your NLE.

A fine fixed groundglass may eventually resolve sharper than a MiniDV/DVCAM 3 x CCD array can resolve and for practical purposes, the fixed groundglass may be all that is required. It is more compact, far less weighty and thus more compatable with the purpose of small lightweight camcorders.

Figuratively speaking, to get into that last ten percent of perfection, you might need to get into the moving groundglass. To get into the last five percent you might need to hire a Mini35.

There is something to be said for home innovations and a web based R & D team of hundreds? thousands?


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