Hi Alex, etc,

as previously posted Minolta screens are great- but couldn't find one without markings- sounds like this Type "C" is the answer. However there is hint of grain

Here is another twist.

I actually like some grain in GG- but because it is the same in every frame looks wrong.

In film of course one has grain but it is different pattern in every frame- so distincly a "film look".

What about moving the GG screen slightly, and slowly so that although the grain is not blurred, it is different in every captured frame??

Vincent

Seems like the screen type C is *not* made with the same microlens technology taht produces grainless image? Judging by price, microlens-made type G is also 50% more expensive than C.

David: the markings are faint on the image that was displayed online when I bought the screen, to the point that I thought it was a clear screen. In reality they are engraved into the flat surface (the G screen is acually a fresnel, so it does have a curvy side that faces the cam in my mini35 adapter). I was hoping that the marks are painted and thus I could remove them - but this does not seem to be the case.

Any thoughts on the BeattieScreens? They purport to be way brighter and from their descriptions look like a fresnelized GG like you describe of the Minolta. They definitely have clear (in about 1000 different shapes - mounted in frames, etc.)

Beattie Link
 

Alex,

I was actual suggesting a software filter to remove any distortions the markings produce in the output stream. This would greatly depends on who damaging the markings have on the final image.

David, I would not rely on software for that... If we are panning, then the software may have enough info to remove the "obstructing" markings; but what if the image is static?

BTW, I did understand your question correctly, then jumped through the thought as above and posted my reply accordingly. Sorry, too many things going on, I'll try to be more coherent next time :)

This is turning into a great conversation!

heath

I found a microlens focus screen without any markings here:

http://www.intenscreen.com/products_...mat_contax.htm

I ordered it from B&H for $79.95 here:

http://www.bhphotovideo.com/bnh/cont....x=4&image.y=5

I will let you know if it works when it comes in. It is a special order item which means no return and it will take two weeks to get here.

Roger

Focus Screen
 

How about finding a grainless focus screen for a medium format camera (with marking or without) ? It may be big enough that breaking off only a portion of it without the marking would work well. What do you think?

Right now, for testing purposes I'm just using a piece of plastic diffusion cut to the size of a 35mm frame and stuck flushly against my condenser. Could a similar piece of a focus screen work? If the screen was big enough.

John

John,

I was trying to go that way, but Minolta support could *not* tell me which of their larger focus screens are made with microlens technology. left a message with Minolta engineers but wouldn't hold my breath for them returning the call...

Alex,

This is very interesting. How is this project coming along? Have you heard from Minolta? Would not Nikon or Canon have similar screens? I'm surprised that here are a lot of Canon people on this site. Maybe someone could help.

Mike

Mike and all,

Minolta does not seem to have any acute matte aspherical microlens screens *without* markings and/or grid.

I asked them to produce a custom focus screen for me without markings for $$$, but their Japanese guys are not interested.

According to Minolta engineers, said focus screens are made in 100,000s at once for years in advance.

Originally these screens did NOT have markings. However they were etched later on all of them.

And no, minolta did not keep any of the original unmarked focus screens that could be traced...

One more bummer: there's a very small, faint circle right in the middle of the focus screen. It seems to be INSIDE the plastic, having nothing to do with markings per se.

So even when markings are not there, the circle will still show.

I do not know whether the circle is part of the focus screen design or a fresnel artifact or what.

All in all, best shot seems to have this focus screen custom-made (in which case I'd prefer it as a circle 49mm in diameter so it'd fit inside the 52mm filter ring) by some optical company that possesses the microlens technology.

Any leads?

Some Leads
 

Reflexite Display Optics
1300 Mt. Read Blvd.
Rochester, NY 14606 USA
585-647-1140, fax 585-254-4940
http://www.display-optics.com/pdf/focusing_screens.PDF

Also, Olympus seems to use microlens focusing screens too - maybe someone can track down a clear one?

http://focuscamera.com/prods/964590614.asp

HI Guys

By the look of it they will do custom orders, over at the Static thread they are looking into it. I think it canbe made fine enough for HD (which might fit in with the Static thread order):

http://www.dvinfo.net/conf/showthrea...&pagenumber=21

(if it comes out with the wrong page, times the page nuimber by 2 or 4, I'm using 50 or 100 posts per page)

They also found a very fine Nikon type D, unmarked matte screen:

http://www.dvinfo.net/conf/showthrea...&pagenumber=23

Wayne.

Unfortunately the grains on the Nikon type D are too large for HD use unless vibrated.