Focusing Screen

Hi Guys,

I am new here but I am into 35mm Adapters since 2001. The glasfiber screen is a product for microscopes and astro-viewing. The german shop has just "old stock - grade C" material but.....please listen carefully.....its not ARRI GG.

I know the Arri GG and its bigger.....has no black dots....and I think the fiber cells are smaller. The "astro-fiber-gg" is only for Viewfinder and not for projections, so any Sky-star-watcher (whatever) will not mind any small black dots.

best regards

Alan

@ Edit:

ARRIFLEX is owner of the patent (DE3937885) and is producing this fiber-GG for several companies but the one for use in microscopes a.s.o is not nearly compareable with the ARRI GG for movie or high quality photography cameras. Glasscreen and Bosscreen are lower grade (not durable, heat sensitiv etc) and will cost 200 up to 700 Dollars.

A Similiar patent was also given to a japanese company but i dunno remember which one.

@ Edit 2:

As I recall many buyer had problems with black dots on the fiberglass. There is no guarantee for spotless plates - if you got one without...be happy. Like in roulette!

@ Edit 3:

I talked with a friend of mine - he had contact with the Shop owner. The fiberplates have more and less black dots which is not completely avoidable. He also said for Star/night sky/moon watcher some dots are no problem.
 
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My english was not good enough to explain the problem - I mean that lower grade screens for Projektion and Photography will cost 200-700 Dollar (20cm x 20cm or bigger). The Arri Screens are available here -> http://www.arri.com/entry/ggc.htm

The Online Configurator helps you with the customizing but the screens will be very very expensive. The size usually 35mm (36x25mm or Medium Format or movie camera screens).

If you ment the fiberscreens without black dots for microscopes? They are only available for optical companies in large quantities and in that case......they will be much more expensive as the 30 Euro. In several years of searching I didnt find a reseller for small quantities.

I suggest the GG from AlexMD - they are very good, sharp and brighter than Canon GGs.
 
Alex MD GG

Alex MD GG

Hello...again,

well I got some questions and want to help out.

First:

The perfect focusing screen is from minolta (lasercarved), Arri (Fiberplate) and the english company with B**** in the name. Alle three are expensive....Arri is the most expensive.

Second:

What are the alternatives? Well...there are some DIY focusing screens out there but in the last 5 years...just one.....surprised me! AlexMD DIY Groundglas with different micron grid (5-9-15-25 etc).

His GG are brighter than Canon EE, thinner than Nikon D Screen and with approx. 15-20 Dollars cheaper. His GG have the same size like the canon GG and very famous on the other side :-) The Canon hv20 Forum.

http://www.hv20.com/showthread.php?t=9046 (AlexMD GroundGlass Thread with order details, sample videos and more.)

Read his thread. Look on his Vids at vimeo and tell him...Aykman send you over.

Be Aware:

The image quality is not only provided by the GG/Focusing screen. You need are well made Tube with exact measures for focal distance, you need an achromat behind the GG, and Condenser in front (is not a must). A vibrating GG holder is better than any static.

And the most relevant Point is - learn to set light. You can not film anything with available light. I hate this people who owns a HD cam and a 35mm Adapter and filming in a dark room or only with a 60W bulb.

Go and build yourself a DIY light Equipment. Damn it :-) I worked as camera operator in the 90s......without extra light...you cant geht good pictures. And even if you film in sunlight.....use a white reflektor to brighten up the face or objects. In short.....read tutorials about photography and lighting.

WITHOUT Light even a 2000 Dollar 35mmAdapter will give you shitty pictures/images/look. Sorry, but I red almost 1000 Postings with "which is the best GG...best Adapter....best lenses"..........and no one asked "how do I set up light for a shoot with a 35mm Adapter" :-)

Best regards

Ayk
 
Alex Md's is just another GG grounded. Jim Lafferty offered the same service, but nobody seemed to pick up on it any. That's been played around with for very long time. The fiber screen from Germany resulted in no grain and could be used static. Alex's has to be vibrated. The alternative was to skip the whole vibrate/spin GG solution.
 
Hi,

well after a little talk with the seller of the fiber plates - he said that the plates has definitely dark spots and almost all plates have more or less amount of dark spots. If someone got 100% clean...than its luck.

He also said that the fiber GG should also used in a vibrating holder.

AlexMD GG are clean...50% thinner...and 50% cheaper. Just as advice. With vibrating GG holder from Daniel or Toni or selfmade...you can get very good pictures.

I believe you that the fiber are working well in static but I saw some footage of users...and they had dark spots in the pictures....not small ones...! Only postmasters footage seems to be clean? Or not?

I just made a suggestion for a good and cheap GG. I wasted money with Nikon D and Canon EE focus plates.....in the past. And at the moment..AlexMDs GG are the best DIY for 15 bucks.

Do you have some other links to footage - made with the fiverplate GG? I would like to see more in better lighting situations......as said....90% of the people are filming in dark rooms :-)
 
At the end of July I will have eight custom fiber screens specifically designed for Brevis35 with AR coating, 4 microns fibers, correction for enhanced edge sharpness and black spots smaller than a pixel in 1080 res ccd. When I will have them I will post my results.

In my prototypes I had no vignetting problem, I could shoot even with no vibration, with a small defect in the blurred part of images (when I was stopping down), that was vanishing the moment I turn on the vibration. I could stop down to F16 with no visible grain, aperture control was exactly as expected linear... no weird behavior like it is on standard Brevis35 screens. Because the screens don't need a diffusion side they are very sharp and the contrast is retained with no diffusion or halo effect at all.

The only problem is the light loss, which is combined with my relay loss (in F4) to 1,8 stops. In contrast of 1,2 stops with CFle1...

There is no difference from the Arri screens. I can't disclose the cost of these screens but there will be less than Arri's.
 
@ Evangelos

You dont have a price yet? You ordered the GG or not?

Where did you buy your fiberglasses? British company?

I did some research and it points out that they are different fiberglasses - one is the patended ARRI GG and the other is a third party company which is producing "Grade B" fiberplates (licensed process from Arri with bigger fibers). Later is the fiberplate with the black dots.

I was able to see some new material with the cheap fiberglass - they are approx. 10 black dots on it....but 2 very big one.....with vibrating the 8 others disappear but the big ones are visible in bright light...like dust....or soft grey spot. So if the dots are small....no problem.

@ Dingles

Nice website. Thanks for the Link. :-)
 
In my opinion, my opinion only....if you have to vibrate the screen count it out for me. you can't stop past 5.6 most of the time..and you can't have high shutter speeds. i'm gonna stick with the good ole spinner or when the holy grail GG for static comes out.
 
I'm not allowed to disclose pricing due to forum rules.

The manufacturers is a grade AAA one. The GG are being passing strict QC from the manufacture because of the specs of my order. I can't disclose him also for obvious commercial reasons. But its a major one and we have very close collaboration, the sampling period was five months, I tested almost all fiber screens that ware available from him.

The fiber does not vignetting because of the large entry acceptance angle so wide lenses and small exit pupil lenses (like F3 lenses) are working up to F11 with no visible problem.

The screens are designed to work with Brevis35. And thats because is the only exchangeable GG adapter in the market today.
 
a ball park figure isn't against the forum rules.
you should check with Daniel's GG holders which allows interchangeable screens as well. which market are you geared towards more, the peolpe who own a brevis or those who simply want a GG?
 
Very interesting. Are these available?





Michael Pappas
Arrfilms@hotmail.com
PappasArts & Arrfilms Main site
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CONTACT VIA AOL INSTANT MESSENGER
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Evangelos Achillopoulos said:
I'm not allowed to disclose pricing due to forum rules.

The manufacturers is a grade AAA one. The GG are being passing strict QC from the manufacture because of the specs of my order. I can't disclose him also for obvious commercial reasons. But its a major one and we have very close collaboration, the sampling period was five months, I tested almost all fiber screens that ware available from him.

The fiber does not vignetting because of the large entry acceptance angle so wide lenses and small exit pupil lenses (like F3 lenses) are working up to F11 with no visible problem.

The screens are designed to work with Brevis35. And thats because is the only exchangeable GG adapter in the market today.
Click to expand...
 
How does the Nikon D focus screen compare to a Brevis CF1 FS?

Im just trying to gauge the performance of the Nikon D...

Pappas
 
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Hi,

I didnt geht it? What Do you mean with "timest"? What will I get????? :-)

New links to optical comanpies with GG (from Mathiaspaul and some are maybe reposts):

http://www.brightscreen.com/enter.html (BrightScreen, ProScreen)
http://www.intenscreen.com/ (Beattie Systems/Reflexite, Intenscreen)
http://www.camerascreens.com/General_Info.shtml (Intenscreen)
http://www.mattclara.com/maxwell/ (Maxwell Precision Optics, Hi-Lux Normal/Brilliant/Ultra Brilliant)
http://www.katzeyeoptics.com/ (Katz Eye Optics)
http://www.schoon.de/bosscreen/bosscreen.htm (BosScreen - not for SLRs)
http://www.35mm-adapter.de/index.php?page=...ent=allgemeines (BosScreen - Glasscreen with Parafin)

This morning a friend dropped his "cheaper-grade B" fiberscreen of at my place. Well, its small...too small.....you dont get the size of a Canon EE Screen (38x25mm). Due to the shape of the fiberplate - you will have approx. 39x16 maybe 39x18mm. The german Astroshop does not offer bigger screens.

The fiberplate has also black dots - this time a lot of dots....one big one...fortunately in the left corner. Not usable for owners of 35mm Adapter based on Medium Format lenses. Its too small.

I have to build a new GG holder for this and tweak the vibrating motor.........and hope to post some footage next week.

Does anyone has a source for good prisma (90,100,120 degree)?

regards
 
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Fiber screens are an expensive game, they really solve all the GG problems in what I'm aware of, except of the light loss... The light loss, edge sharpness and High MTF is a problem to be solved by the relay lenses.

When I receive the GGs I will test them and I will give one or two to persons like Philip to try them and tell us his opinion I will then do correction to the design and then I will be able to release a price. The target price is in the range of 300$ to 500$, I say target because the GG is still in R&D and with all these expensive coatings to mimic film response, I can't estimate the final price accurately also I don't wont to get in a new opposition with site moderators. I can answer only direct questions about features from users and I can't advertise prices.

The size of defects will be less than 25microns which is 1,5 pixel in 1920 x 1080, so with vibration they are invisible.

The size of Brevis35 GG holder can accept also a Canon EEs screen (with a small modification) so my GG will be fitting Daniels holders. I will sell GGs to everyone because I'm not planing to build my own host adapter since I thing its a waste of time when we have so professional solutions like Brevis35 is.
 
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