Focusing Screen

@ Evangelos & CLA35HD

The CLA35HD works similar to the JVC HZ-C13U and indeed - due to the optical system it reduced the 35mm Format to 2/3 CCD and increases the brightness. As this article also stated:

http://www.dvinfo.net/prohd/hz-ca13u-review1.php

We had approx 1 stop gain :-) The DOF was absolutely the same.....only with the prime lenses it was really sharp with nice colors and a lot of DOF :-) Edge Sharpness was IMHO no problem...very sharp....as you can expect from Zeiss and Cooke.

@ Cinebuddy

I forget to say...6 Dollar for a double package of Scotch tape. In germany we use TESA.....the german competitor of Scotch 3M
 
that's because there is NO gg in that system. You can't lose light if you don't have anything in the way. And you're getting 16mm DOF.
 
Hello. I came across a Fiber Optic Face Plate in the states you can play with. I got it in last night and checked it out. Same problems as with the one in Germany, but it's only 5bux. When I finish my spinner I'm gonna play with this one. It also has a wicket relfection on the side facing the camera. It gets blocked out once there isn't any light hitting it. Grainless as well and no chicken wire, but there are dead fibers.

http://www.surplusshed.com/pages/item/l3172.html

Hint. To mount it Get a 37mm UV filter take out the piece of glass and tape the FacePlate to the Filter...I used electrical tape. Next get a 37to 40something step up ring. Make sure the outer diameter isn't bigger than 49mm. Check out the Thorlabs 2" lens tube. You can use that for your housing. Anyway, tha'ts the first possible way, I'm sure someone else can figure something out.
 
I finally got it - the facts about the german fiberplates with black Dots. They are not ARRIFLEX. These are surpluss parts from the 90s - originally produced by Schott Glass Germany and by the end of 1999 they moved production to the USA and only producing for special optical devices. The Arri Screen is brighter and its bigger.
 
@ Car3o: Try to behave :-)

This information is related to the fiberplate (39x36mm) from the Astroshop and not the item from surplus. Buy what you want....i only want to clear the discussion which started in january 2008 and was followed by the postings a few weeks ago.

The surplus part is cheap and good for cheap for amateur purpose . Its too small for any semi-pro adapter. I didnt want to degrade your encounter....just talked about the "other" fiberplate.

regards

Alan
 
Smells like the "fiber screen war" has begin..

:D

I think that even 500$ wouldn't be too much if you would get grainless GG with nice bokeh..

Keep fighting.. :)
 
war??? what are you bugs bunny? just kidding...
the Fiber Screens are the way to go, if you can find them cheap and not damaged. But I'm (me only) not paying anything over 100bux. The bokeh is nice too. I've found a few places with Face Plates, but what guarnatee do you have that they won't have dead fibers as well? How long before they go? Would you pay $500.00 on a screen that has the chance of going to crap?
 
Car3o said:
Would you pay $500.00 on a screen that has the chance of going to crap?
Click to expand...

Well, I guess you can check if the screen is made with no faults..

As I understand, the fauls are made in producing process, and they are not origin in later use..

But maybe I am wrong

:Drogar-Shock(DBG):
 
Just received a Fiber GG

Just received a Fiber GG

Although its a "witness sample", for checking size/fitting on Brevis35 its actually a disqualify by 25microns QC... it has one big defect of 45microns and same smaller at 35microns... the below 25microns are not visible with vibration on.

My first tests, very nice bokeh, no bleeding highlights, no diffused look (since its polished on both sides), I stopped down to F22 on an Ultra prime with no vignetting, there is no grain structure visible even with no vibration, there is no grain visible even in F22, the wide angle 16mm Ultra prime wasn't vignetting even on F22, ahhh and above all, linear behavior of the aperture... the total light loss is 2 stops with camera aperture at F4 and its linear loss on all the range.

The curved side, fix the edge sharpness problem by 60%

More to come with stills and video when I will have a test shoot...

this is a glimpse...

The defect is from top to bottom @1/5 and from left to right @1/3, its an oval shadow... hard to find though...

I forgot the +3dbs thats why is a bit noisy... Its being shot with Varicam @ P2 mobile with AVC-Intra 100 and my GG.relay along with Brevis35.
 

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So do these screens degrade over time? What about actually handling them, are they fragile to the point where swapping them out could cause damage? The idea of stopping down to f22 on a vibrating adapter is primo. What causes the qc problems anyway?
 
you say 2 stops at camere f4, how does that compare with the light loss of the brevis cf1? No grain pretty much rules.

oh yeah, are you going to develope these for smaller cameras such as the hv20/30?
 
cinebuddy said:
So do these screens degrade over time? What about actually handling them, are they fragile to the point where swapping them out could cause damage? The idea of stopping down to f22 on a vibrating adapter is primo. What causes the qc problems anyway?
Click to expand...

No they don't degrade, fibers are used all over the world in all possible environments... with no aging at all. Its easier to handle the fiber screens because its a piece of glass polished in both sides so is the same handling as a lens... its not a fragile diffused plastic... The blemishes (defects) are happening in the manufacturing process its from particles that enter the clean room area, from bended fibers etc. Its a matter of statistics to get a really clean fiber screen, for below 25microns defects 1/3 are passing QC, for below 12microns is 1/10, for below 6microns is 1/50... so the cost rises accordingly... but the 25microns are not visible with vibration at any F stop. The QC is passing the screens from an inspection and puts them in levels Grade A = defects less than 25microns Grade AA = defects less than 12microns. The projected size of a pixel in the screen is around 13microns @ 1080. So its questionable if a Grade AA could work as a static screen since it will look like a dead pixel... both are very good for vibrating GG... for static its needed below 6microns...

astigmatic said:
you say 2 stops at camere f4, how does that compare with the light loss of the brevis cf1? No grain pretty much rules.

oh yeah, are you going to develope these for smaller cameras such as the hv20/30?
Click to expand...

With the same light on the camera lens I use 5,6 and with the adapter I need 2,8 so its about two stops loss. My GG is for Brevis35 so whatever fits to Brevis35 is working... it seems to lose a bit more than CFl1...
 
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seems to be very sharp. Can you post some footage without
that much noise?
How does it perform with a wide-angle lens?

Does this screen work without a condensor lens?
 
not going to deny it's sharp. but an added 500-600 dollars to your brevis isn't something i personally be interested in. but others might.
 
MatzeB said:
seems to be very sharp. Can you post some footage without
that much noise?
How does it perform with a wide-angle lens?

Does this screen work without a condensor lens?
Click to expand...

The screen is curved in one side so its like a condenser and a GG together...
Wide angles are behaving the same as normal lenses no vignetting no edge problems unless inherit to the lens. The fibers have an entry angle (or acceptance angle) of 180 degrees so they grabbing what ever it falls to the pipe/surface (fiber)... I'm waiting to see the final GG that has also AR coating...

Car3o said:
not going to deny it's sharp. but an added 500-600 dollars to your brevis isn't something i personally be interested in. but others might.
Click to expand...

It is also not diffused since there is no diffused side on the GG...

its less than that, but I can't disclose, its against the rules...

My aim is to maximize the performance of what I own and not to buy another adapter... so the expense is minimal in contrast to what you save by not buying a new adapter... and with properties that are very rare since its a fiber GG... what Arri viewfinders have...
 
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