Fiber screens, the future of the 35mm adapters?

capitanfracassa said:
Another concern with the Brevis is weight.

The GG plate sits on two dainty rods. This fiber GG looks heavier. Is there a risk of breaking the rods. Did you consider that?
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This was one of my first considerations... the rods are three...

For what I see it seems that the holder can withstand at least 3 times heavier GG than the fiber screen... it doesn't show any sing of problem whatsoever...

Regarding the Monday shooting, it was not a big thing, we used old ARRI SS 1.3 MKII with 35mm @ F2 and 85mm @ F2... whats interesting is the bokeh in the long shoot...

http://www.motionfx.gr/Files/Fournaris1.mov
 
I've noticed in these example movies that some of the out of focus elements have a sort of "textured shower door glass" look to them. For instance the back side of the table in the close-up at the bakery. Is this because you are using your fiber screen in a stationary way, and this might disappear if it were vibrated or spun? It's not nearly as objectionable as the pattern you get when you don't move a standard ground glass, but I still notice it.

Duncan
 
frobozz said:
I've noticed in these example movies that some of the out of focus elements have a sort of "textured shower door glass" look to them. For instance the back side of the table in the close-up at the bakery. Is this because you are using your fiber screen in a stationary way, and this might disappear if it were vibrated or spun? It's not nearly as objectionable as the pattern you get when you don't move a standard ground glass, but I still notice it.

Duncan
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On these shots it was vibrating... But I'm trying to understand what are you see...
Its probably compression artifacts from H.264 I use 6Mbits limited stream at 720p...
 
It's not as obvious when it's a still frame, but look closely at this part when the movie is playing:

http://www.backglass.org/duncan/example_section.jpg

If it were compression artifacting, I would think it would be changing more from frame to frame. Partially it's because it's not changing from frame to frame that it looks to me like something that was captured as part of the image.

Now look at the "Obscure Glass" example on this page. That's what it reminds me of:

http://www.showerenclosureva.com/glass_textures.html

Duncan
 
Ok I will do it tomorrow... you see its 23:45 in Greece so I'm home now, tomorrow in the lab that will have access to my Mac Pro I will do it...

It looks like it was turned off the vibration.... check out the first picture on this thread, the comparison between ON and OFF... its very similar... It can easily run out of batteries and because its not easy to see the screen, none can notice it...
 
This screen would be interesting for DIY. So, Evangelos, a couple of questions for you:

1. Could I buy a fiber screen from you the same size as the Canon EE-S screens to fit into Daniel's GG-holders?
2. Does this screen need a condenser lens to avoid vignetting like the DIY screens?
 
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Hmmm, I can't see the video - Quicktime gives me that useless "I need another component" message, that just takes you to the generic QT components page without telling you what you're missing. This is on a Mac at work...I can try it again on my Mac at home that has Final Cut installed... often that has whatever the missing piece is.

As long as we're asking for pricing, how much for a 4" diameter circle of it with a hole in the dead center?

Duncan
 
frobozz you need the Blackmagic codec

http://www.decklink.com/support/software/


edit:

Yeah, looks like noise and weird compression artifacts. If this is
how it looks uncompressed than maybe the original capture settings
introduced the artifacting. I'd would try -3db and higher quality capture
settings.
 
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Norbert said:
This screen would be interesting for DIY. So, Evangelos, a couple of questions for you:

1. Could I buy a fiber screen from you the same size as the Canon EE-S screens to fit into Daniel's GG-holders?
2. Does this screen need a condenser lens to avoid vignetting like the DIY screens?
Click to expand...

I was using EE-S in Brevis 35 before I put the Fiber... Fiber is much better....

The size is 39.1mm x 25.7mm so talk with Daniel and he can make something for you he has done it in the last three months for another client...

I don't use condenser lens in the above examples... the FiberScreen exhibits a static minimal vignette in all the range of the aperture, you can check out the stop down test...

In the next experiment, that is on the manufacturing state, I will try a slightly concave side to grab the steep angled rays from lenses like the FD 24mm F2.8 in order to minimize the vignette to zero... I will have the samples first weeks of January because they have to build the special aspheric tool to do it...
 
frobozz said:
Hmmm, I can't see the video - Quicktime gives me that useless "I need another component" message, that just takes you to the generic QT components page without telling you what you're missing. This is on a Mac at work...I can try it again on my Mac at home that has Final Cut installed... often that has whatever the missing piece is.

As long as we're asking for pricing, how much for a 4" diameter circle of it with a hole in the dead center?

Duncan
Click to expand...

Follow the Inexistance link:

Inexistence said:
frobozz you need the Blackmagic codec

http://www.decklink.com/support/software/
Click to expand...


When I will finish the experiments I will discuss with you guys what could be a round FiberScreen in term of diameter and size of the center hole. I will need one dimension to fit most of the applications... Beware that a 100mm fiberscreen could cost 1300 euro's... its very difficult to build it in that size with no blemishes...
 
Evangelos Achillopoulos said:
Follow the Inexistance link:
Click to expand...

OK, that did the trick! I still see the same issue, so that means it's not compression artifacting, right? I'm going to go with your theory that your batteries had run out and it wasn't actually moving.


Evangelos Achillopoulos said:
When I will finish the experiments I will discuss with you guys what could be a round FiberScreen in term of diameter and size of the center hole. I will need one dimension to fit most of the applications... Beware that a 100mm fiberscreen could cost 1300 euro's... its very difficult to build it in that size with no blemishes...
Click to expand...

Hey, but if it's spinning a few blemishes don't even matter, right? That's the whole point of spinning it. A bunch of blemishes that all happened to line up at the same distance from the center...well, that would be a problem. But a dozen or more randomly dark fiber "pixels" shouldn't be a problem at all.

I came up with the 4 inch diameter because I am convinced that one of the big vignetting problems with all the adapters is how close they cut all the dimensions. Even something like the M2, which has a seemingly big ground glass disc, is actually cutting it *very* close on fitting the image rectangle on the glass while avoiding the outer edge arc, the shadow of the motor, etc. Optics get weird near edges, so I would prefer to have a very generous area around the main image area, clear of all edges. This would also help when trying to cure misalignment of things. With an HVX200 and its misaligned CCD, you don't have any leeway on the M2 before running into an edge of something. The only choice is to zoom in closer on the GG. With a 4 inch diameter disc you could even project the lens image onto it in the other orientation (to left or right of center instead of above or below) if that made sense for some reason.

Duncan
 
Evangelos Achillopoulos said:
Ok Duncan, I will check the possibility with the factory, my fear is the cost...

Did you check the first page of the thread the very first image?
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Yes, I fear the cost too! Also, a spinning disc is incompatible with the idea of using a concave surface to help with vignetting. I hope the concave surface is not required. But maybe the ability to accept blemishes will help the cost?

If by "first image" you mean the third example image contained in the first image (non-vibrating fiber glass) then yes. It's hard to tell from a still, but that does look a bit like what I'm seeing in the example movie. So probably it wasn't vibrating.

The really weird effect is in the second image in that first image, with the CFXL GG vibrating! What is up with that weird swirly pattern on the edges of the highlights?!

Duncan
 
frobozz said:
OK, that did the trick! I still see the same issue, so that means it's not compression artifacting, right? I'm going to go with your theory that your batteries had run out and it wasn't actually moving.
Duncan
Click to expand...


It is definitely artifacting.

artifacting.jpg
 
Hang on, I thought he said the footage with the BlackMagic codec was uncompressed. How do you get jpeg artifacting in uncompressed footage?

Duncan
 
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