Am I right if I assume that:

The bright screen should be designed to work with all lenses down to f/5.6 and it will have the Precision Matte random micro lens construction with elements of varying size and sensitivity.

The bokeh screen should have finer micro lenses than the bright screen along with a steeper parabola of focus to make the out of focus areas appear more filmic, identified by light discs with sharp edges in OOF areas.
However, this screen should not be recommended for slower lenses because it wouldn´t be that bright. The difference in illumination will be roughly one f-stop.

Thanks in advance,
T

I would rephrase that problem:
1. My opinion is that bokeh isn't characteristic of screening glass but it is characteristic of photolens. I explained it here: http://www.dvinfo.net/conf/showpost.php?p=504514&postcount=23 .
2. Your assumption is only right by next to cases:
a) if You reduce my 1-st point to bokeh problem
b) if You're using traditional screening system - projection on groundglass.

I´m speaking little bit in Canon´s manufacturing/marketing terms here.
By my research Canon manufactures at least two types of clear focusing screens for modern DSLRs. One of witch is described as brighter, standard screen and another with finer micro lenses along with a steeper parabola of focus designed for precise manual focusing with brighter lens.
My assumption was based on that information.

By all means those screens are traditional modern focusing screens in general.

Regs,
T

when i posted earlier i just skipped words "micro lens" reading Your intropost. Microlens arrays are step further from groundglass and not so traditional. I'm curios now :). Have You something specific(microlens array as product) in Your mind?

As far as I know Canon has those two focusing screens that utilise microlens.
>The standard and brighter one (http://www.cinedof.com/screen_eea_2184.jpg)
>And the super precision one (http://www.cinedof.com/screen_ees_2186.jpg)

I´m going to visit local Canon facility in next few days to verify if those screens are any good.

Canon sells those for $/€35 each.

Regs,
T

i tought sensor will take picture directly ...? Or is it for presenting image via VF

It´s for for presenting image via VF.

You've seen both Canon versions? Asking because I actually have not seen any microlens array in photocameras. But those which using ordinary GG are grainy as hell.

I`m getting the brighter one later today but I´m afraid that we must wait another 10days to get the one with super fine microlens as there wasn`t any in stock.
Good thing is that I can already design a screen holder for those screens and see how they work with my unique leaf spring biaxial oscillator.
Therefore I can compare a Beattie, Nikon and those made by Canon.

For now I know that our HVX will need an achromat to get close enough but I assume that a sub $100 achromat also manufactured by Canon will be enough, we`ll see. If nothing else we can perform lab tests with 8Mpix DSLR with real macro lens attached.

Regs,
T

Basicly grain is seen right from photocamera VF. Just for saving time.

Frank, it`s well known that focusing screens from SLR cameras have at least some degree of visible grain but that`s not my main concern at all beacause my design blurrs the grain with oscillating motion therefore reducing grain noise visible to camcorder. One limitation of that design is that with higher and higher shutter speeds the grain becomes visible again as the oscillating motion isn`t fast enough.

I`ve had many (D)SLR cameras and their viewfinders are sometimes like night and day. I currently own three Canon SLR cameras and their viewfinders are quite grain free.
To illustrate that look at traditional ground glass and laser matte one (http://www.cinedof.eu/lazerscrnvlowup.jpg) and compare it with the earliest microlens focusing screen that Canon introduced already in 1971. (http://www.cinedof.eu/scrnenlarge.gif)
Not to mention that spacing between ring peaks on a Fresnel lens on that screen were only 0.03mm resulting in much sharper (viewfinder) image.

I quess I`m not gonna waste my time.

Regs,
T

rather Your experiment will be very interresting - no doubt. As i said earlier, i never seen microlens arrays used in such application. I'll wait rather from such experimentations good news like breaking some main physical trade-off law:
t-stop vs hotspot
grain vs t-stop
etc

btw. what is the size of those plates?

Those sceens are about 36x24mm in size covering full 35mm still photography frame thus giving even shallower depth of field than normal cine lenses for the same t-stop.

All products are available here:

Canon Focusing Screen Ee-A (http://www.adorama.com/ICASEEA.html?searchinfo=Ee-A&item_no=1)
Canon Focusing Screen Ee-D (http://www.adorama.com/ICASEED.html)
Canon Focusing Screen Ee-S (http://www.adorama.com/ICASEES.html)

But don't these have focusing circles? We've discussed the Ee-A and Ee-S over on DVXuser and both were confirmed as having focusing circles. You'd have to zoom in beyond that in order to get a usable image, and at that point you're negating the 35mm FOV, aren't you? Just wondering. I'd love to see the results of these tests.

I have Nikon D100, Conax RTS II Beattie and Canon EE-A here on my desk and neither of them doesn`t have any markings. All of those screens cover full 35mm frame.
All of those screens are frensel type focusing screens which doesnt require any additional optics (like PCX lens) in DOF adaptor design when camera is able to focus close enough to 35mm frame.

Ben Winter originally tested the Nikon D100 screen and that gave me an idea that maybe other modern (D)SLR`s have focusing screens with two layers too, one premanent in-camera layer with markings and another (interchangeable) screen without any markings.

Regs,
T

Most interesting. I appreciate the information. Apparently I was misinformed about the Canon screen. Always wanted to give it a try but didn't want to waste my money if it wasn't free of markings.

Ok, I bought the EE-S screen an tested it. Toenis, this is an awesome find, thanks so much in the name of the DOF DIY comunity!
Obviously I cannot speak for the comunity but I do strongly believe that this screen will help many of us.

My first tests yesterday and today suggest that the Ee-s is very good: Invisible fresnel, very small grain, good bokeh and, surprise, no excessive lightloss at all (the ligtloss in comparison to the EE-A can be neglected between F 1.2 and 2.0)

I'll now start a separate thread on this screen and how to combine it skillfully with an achromat or close up lens to form a static adapter easy to DIY.

I have been looking for an affordable PLAIN focusing screen for sooo long. Thanks for pointing these screens out guys! I have found a place in England where I can buy them from quite cheap. I will get one and give it a try!

Yes they are plain - and they may be among the best - even compared to the much more expensive models. But that will require some more testing than I did today to veryfy their "universal usefulness" ;-)

I'm not sure if it is image of real EE-S screen, but preview image on BH PhotoVideo have circle in middle of it. It's not real marking but its part of focusing screen.

http://www.bhphotovideo.com/bnh/controller/home?A=details&Q=&is=REG&O=productlist&sku=402221

I have something similar on my Minolta 5D/Sony Alpha focusing screen. It is almost invisible at f1.4-f2.0 but at f4.5 it is noticable even when focusing screen is vibrating.

some screenshots from my focusing screen at http://35mm.prozone.sk

So I'd like to ask..is your EE-S really "clean" or there is same circle in middle ?

IF this circle only appears around f 4.5, it may be also present on the ee-s. However, using a f 1.8 lens I did not see anything that resembled a circle on the diffusion screen. Also, nothing could be seen looking at the screen with the naked eye. I did also move it over a lightbulb in the background (without lens) to look at the diffusion in a magnifying glass, but nothing appeared.

Unfortunately, it is quite possible that this circle is there at F 4.5. And, which is worse, I will now worry about it all week because next time I can test with F stop lower than 1.8 is next weekend. :-(

Although it may not be good news, thanks Ivan for pointing out a very important detail.

Ivan, it`s not real image of the EE-S focusing screen on BH site.
Frensel rings on EE-S go all the way to the center not as shown on that image.

Older EOS screens had that problem as you pointed out, those didn`t have frensel in the middle so screens were absolutely clear in the centre - about 5mm in diametre.

I hope I can post some EE-A and EE-S footage soon as well as D100 and a clear Beattie must assemble our adaptor production prototype first.

Best regards,
Toenis