Focusing Screen

Hi mate! I have just sent Manfred an email about the fiberscreen. Appreciate your input a lot..
Just wondering what screen holder you used and which one of these fiber boards you bought ?

Fiber board
octagonally 30x30 mm, h = 2.0 mm for Unit price 15,-- € Fiber board
octagonally 36x39 mm, h = 2.0 mm for Unit price 30,-- €

Thanks!
 
That backfocus issue was driving me nuts.

So I sloughtered one of my old Zeiss Lenses and used the housing - verry elegant micro collimation now hehehe (picture 1)

The components: +10 Achromat in a tube, Zeiss housing with ARRI GG and my trusty Petri 1.7/50 Prime (picture 2)

As you can see I have to hold everything by hand. (picture 3)

This is not represantative since nothinmg is lined up in the propper angles, light drops in and what not but it gives you an idea of no visible grain in an static adapter. ( Picture 4)

With a housing that helds everything together it would give a marvelous picture.

You can see a grid on the ARRI screen - that is dependand of the light angle.
If you got it 100% square to the HVX lens it disapeers.

Frank
 

Attachments

  • 100_6642.JPG
    100_6642.JPG
    136.4 KB · Views: 0
  • 100_6643.JPG
    100_6643.JPG
    159.6 KB · Views: 0
  • 100_6645.JPG
    100_6645.JPG
    150.8 KB · Views: 0
  • self1.jpg
    self1.jpg
    113.6 KB · Views: 0
  • self1 01.jpg
    self1 01.jpg
    107.1 KB · Views: 0
Last edited:
So I sloughtered one of my old Zeiss Lenses and used the housing - verry elegant micro collimation now hehehe (picture 1)

Hehehe.. Good one! :Drogar-Happy(DBG):

Looks very promising! Not so sharp, but I guess it is from jpeg compression and all other lights that are falling into groundglass..

Thanks Frank!!!
 
Yeah, I need someone with a lathe to make me a housing.

It was pretty hard to hold everything in the (almost) right position/angle/distance and make a screenshot with the other hand (with OnLocation).

As you can see at the noise there was not much light eather. Just the desk lamp in my office.

But I´m still amazed that this is the first GG without any grain at any stop. I know there is the gel GG from Movietube but it looses much more light.

Frank
 
"Yeah, I need someone with a lathe to make me a housing."




Do you have a cad drawing with the correct measurements?



:)
 
OK. I asked my pretty German girlfriend to call up Manfred and ask him for the 36x39mm fiberscreen. He is not too keen on English so we translated via her. Anyway, he says that all of his fiber screens have little black points (??) Maybe that means smudge marks, maybe dead fiber ends that will act like a black spot.

Frank, I am keen on trying these out - just wondering if you actually got a perfect piece for yourself - one with no "black spots" ??
 
"Yeah, I need someone with a lathe to make me a housing."
Do you have a cad drawing with the correct measurements?
:)

Thanx for the offer, but as you can see I live in Germany and I have a friend make it for me localy.

@zcream

I think they are surplus or "not perfect enough" for ARRI.
Mine is chiped at the corner (not critical area) and is not a perfect hexagon.
But I have no spots at all - maybe sheer luck.

Frank
 
I'll lookk for that - maybe one with spots or chips only in the corner..
Any idea where we can find ones that are perfect for ARRI - and do not cost 1200 bucks..
That price is just ridiculous..
 
I´m workin on it.

I had a hard time to figure out the right distances between Achromat, GG and lens, regarding CA, corner sharpnes and vignetting but I think I nailed it.

Looks pretty promising.

I´m waiting for my machine shop to return the housing so I can do some test shots.

@zcream no, but i found 2 sites that got a load of alternativ diffuser screens and other intersting optics for adapter builders - so that may be an alternative.
In the momement I´m happy with that fiber screen.

http://www.edmundoptics.com
http://www.thorlabs.com/Navigation.cfm?pageRef=8

Frank
 
I ordered 2 fiberscreens from Manfred for testing.

I have also found some intersting optics commercial and experimental at :
http://www.anchoroptics.com

I ordered one Achromat, one GG (diffuser) for my DIY DOF adapter and two Tapered Right Angle Porro Prisms for my future plans to make a flip module.
 
Here is a response from Manfred in German - English translation below :-

>>>>>
German :-
es gibt leider keine ganz einwandfreien Faserplatten, auch nicht in dem
KB-Format. Ich kann das leider nicht ändern. Sie sind nicht der Erste, der
diesen Wunsch hat. Alle haben diesen Wunsch. Letztendlich kaufen viele diese
Platten und kaufen sogar nach. Wie man mir sagt, machen es einige mit
Rotation, andere mit Vibration.

>>>>>

English
>>>>>>
Unfortunately, there is not a proper fibreboard, not even in the
KB format. I can unfortunately not be changed. You are not the first to
This desire. They all have that desire. Ultimately, many of these buy
Sheets and even buy. As you say, do it with some
Rotation, others with vibration.
Unfortunately, I can no better message to send.
>>>>>>>


Leider kann ich Ihnen keine bessere Nachricht zukommen lassen.
 
The thorlabs and Optosigma did not get as good a rating as the Canon EE-a. Some people tested these a couple of years ago..

I´m workin on it.

I had a hard time to figure out the right distances between Achromat, GG and lens, regarding CA, corner sharpnes and vignetting but I think I nailed it.

Looks pretty promising.

I´m waiting for my machine shop to return the housing so I can do some test shots.

@zcream no, but i found 2 sites that got a load of alternativ diffuser screens and other intersting optics for adapter builders - so that may be an alternative.
In the momement I´m happy with that fiber screen.

http://www.edmundoptics.com
http://www.thorlabs.com/Navigation.cfm?pageRef=8

Frank
 
Back
Top