What's new
Medium Format Forum

Register a free account now!

If you are registered, you get access to the members only section, can participate in the buy & sell second hand forum and last but not least you can reserve your preferred username before someone else takes it.

Focusing screens

W

wolfgang

New Member
Hi there!

Is it really a benefits to use Accumate D focusing screens? I used borroughed an older which is much darker but imho also very good for focusing due to the split image. The price is alos interesting too: about € 30,00 in good condition (hardly any scratches).

Any statements very welcomed!

Thanks in advance
Wolfgang
 
(Minolta) Accumate D is really great but also the ones of Mr Bill Maxwell maxwellprecisionoptics@toast.net He is in the $145 range for a plain HI-LUX Brilliant Matte . The Beattie (www.intenscreen.com) has an old test of Popular Photography for download. Badly scanned, but OK. I think a have a plain hassy D (42204?) left for USD 100 if you are interested, (went to Rollei 6003), Rainer from Zurich
 
Hi Rainer!

Thanks, the plain I have by myself, for portraits I think splitt image is far better.

Regards to Zürich
Wolfgang
 
The Acute Matte (note spelling ;-)) screens are very bright, but lack some of the "snap" the older screens have. The older screens however are a royal pain in the nether regions when trying to focus in low light. I find the best compromise is indeed the one Hasselblad presently offers as "standard issue" with all their cameras: the Acute Matte with split image rangefinder. I just wish they put the divider diagonally, suiting both horizontal and vertical lines (though with less accuracy).

However, the old split image rangefinder screen is a very fine screen too. As longs as you don't use long, f/5.6 lenses, out of bright sunlight. ;-)
 
I just bought it for €25,--; it is true a royal pain when being used a acute Matte, but it is very good for focusing.
 
You will have to adjust your TTL Prisma/ light meter now, did you read that test review at the Beattie web site? Gut Licht :)
 
Servus Rainer!

As I have just started with Hassi I do not have a TTL Prisma, but thank You for Your advice!

Regards
Wolfgang
 
I just bought an Accute-Matte on EBAy for my 500cm and I think I got taken (id so I'm only out $30.00. It is quitea bit darker that the original and I can see the curved lines. Also the cross hairs are darker black and longer than what came with the unit (Also EBAY). What do you think? Did I pay for just an old non-Accute or is something wrong with this one? Thanks
 
AcuteMatte screens are considerably *brighter*, it is really very obvious. So, maybe your old screen was an AM, and the new one is not? Difficult to judge from here. But basically if the new one is darker than the old one you have I would say you have been taken.
 
The original Acute-Matte screens did not have any markings on the frame. The later D-type had a semicircular cutout in the frame.
 
OK, I got an assurance from the seller that it was indeed an acute-Matte and it does have the box. Alos, the seller of my original one has no idea what it is. The comendium was not much help so maybe someone here can help. Allow me to describe the two and tell me what you think. The one I got with my used system does not have the cutout. It has a very thin, almost invisible cross hairs on it. The curved lines on the screen are almost invisible also. The one i got in the AM box is "cloudier", the cross hairs are much darker black and I can detect the curved lines on the screen. Any guesses?
 
only the second generation Acute Matte (i.e. D) are the good ones (there are older ones #42165 for 500CM). Jack, note that Hassy USA runs an outlet store for US domestic guyz...
see pic enclosed of plain Model D Hassy P/N 42204
5466.jpg
 
I have a 42165 in my 500CM and I am very happy with it. So I do not understand what would be so wrong with them?
 
Wilko,

Focus on the original Acute Matte screens is not as "acute" as the name suggests. Though the older type screens are very dim, and coarse, the contrast between the in-focus and out-of-focus parts of the viewfinder image was actually better than when using the very much brighter Acute Matte screens.
The Acute Matte screens aren't just plain screens with a matted surfaces, but employ many optical elements (little pyramids) of microscopic scale. The result is that yur not watching light "scattering off" a diffusing surface, but an optical image the position of which isn't defined exactly, but depends a (tiny) bit on your where your eyes are focussing as well. Can get very difficult to focus.
This not only affects how easy you can or can not focus uising such a screen, but also how the out of focus parts look: not quite similar to how they appear in the final image on film.

The next generation Acute Matte-D screens should remedy this problem by being a bit more matted, increasing the scattering/diffusing property of the screen, i.e. being more like "normal" ground glass screens.
But still, there is a reason why the "standard issue" focussing screens have changed from plain Acute Matte D to Acute Mate D with split image rangefinder...
 
Bright-Matte
You guys talk a lot about Acute Matte screens. What about Bright-Matte? That's what I have on my 500 CM and focusing with it is not so bad... but not as easy as with my 35 mm camera to say the truth. Any comments?
 
Hi Qnu,

I had the classical screen with split image initially. I now have the plain (only X hair) AcuteMatte. I like the latter a lot better, I would probably love it even more if it had a split image rangefinder too. Under the assumption that the split-image on the AM is less susceptible to 'blackening' than the one on the classical screen.

I have to admit I use the loupe on the WLF quite a lot on the AM screen. For static objects (landscapes and the lot) that works just dandy. For the fast moving stuff that needs a faster camera I have my Pentax MX 35mm SLRs (.. you can tell I love mechanical cameras I suppose.)

If all this FC screen stuff was not so ridiculously expensive I would have bought an AM with split-image, as it is I am happy with my plain 1st generation AM. I bought my AM for US$ 100 which is IMHO more than sufficient for what amounts to some glorified fresnel stuff, a tiny bit of optical glass and 2 dimes worth of stainless steel frame ;-)

Wilko
 
Wilko,
When you talk about "blackening" are you talking about one side of the "circle" for lack of better term in the screen going black and thus, making it hard to focus?
If that is what you are talking about instead of the whole screen being blacker, then, the problem is that the aperature is lower than f/4 or f/5.6. That is what causes this "blackening" of one side of the split image rangefinder. You can no longer, at that point, use it for focusing. If your aperature is wide open, then you won't have this problem.
 
Hi Michelle,

Yes, I know what the split-image darkening causes. But given that MF lenses tend to have a lesser max opening than their 35mm counterparts I wonder how people like their split-image finders on (say) a 4/150 Sonnar? Or: how useful is the split-image in the latest and greatest AcuteMattes using lenses with less 'light'?

I have the feeling my split-image finder in my Pentax MX screen is less susceptible to darkening, even with F4 or F5.6 telephoto lenses. But I have to admit: this is a *very* subjective theme..

Wilko
 
The split image rangefinder halves darkening depends not just on the aperture used, but on the focal length of the lens, combined with the focal length of the Fresnel lens that is part of the focussing screen assembly.

Which reminds me of another disadvantage of the Acute Matte screens: they only work well with your eye positioned at a certain distance to the screen, and with your eye right on the optical axis of the Fresnel lens. Look at it from a bit too far away, or move your eye off-axis, and you'll see a bright spot on a darker background (again, a Fresnel lens focal length issue). It appears that they were intended first and foremost for use with prism viewfinders.

This is not something peculiar to Acute Matte screens, but they suffer from it more than any other screen i know.
 
You must log in or register to reply here.
Back
Top