Retro-Grouch
Mentor
There's always a wealth of knowledge here on RFF, and I hope I can receive some guidance. I have a Hasselblad PME90 meter prism, which I use with the plain acute matte screen. The combination works perfectly, but my tired old eyes would love to use my other split-image/microprism screen, also acute matte, for its superior focusing. However, Hasselblad recommends against using that screen with the PME90, since the focusing aids interfere with with the spot meter's proper functioning (and of course I use the spot meter most of the time). They do not offer any factor by which I could adjust my readings. Now, I could easily do some trial and error metering with the average and spot meters to come up with a correction, but would that correction be linear across all readings? And if there is an accurate correction factor available, does anyone have that info? I've searched the internet 'til I'm bleary-eyed, but without success. All suggestions are welcome!
Richard G
Mentor
I don't know. I think the worry is that it would depend on the scene and the focus and what the split image in particular does in terms of interference. I doubt there could be a reproducible factor for calculating exposure that is referable to all scenes with a central microprism and especially a split image section of the screen. The manual recommends using the central field metering option with the PME 90 rather than the spot with those types of focussing screen. Maybe it isn't just the pile on he or she would get for proposing a factor for this amongst www 'experts': maybe no-one has found a solution. Ernst Wildi in his Hasselblad Manual just says don't do it. https://books.google.com.au/books?id...screen&f=false
I mainly wanted the PME90 for the height for photographing trees or architecture. If I get more serious about spot metering I reckon I'll be buying a Sekonic meter.
I mainly wanted the PME90 for the height for photographing trees or architecture. If I get more serious about spot metering I reckon I'll be buying a Sekonic meter.
Retro-Grouch
Mentor
You are correct; basically, everyone just says, "Don't!", same as the manual. I'll probably use the spilt image screen and use my feet to get in closer for the equivalent of a spot reading. I feel embarassed to be whining about the inconvenience when, after all, I'm fortunate enough to own a Hassy!
And yes, the 90 degree prism is great for that extra bit of elevation in landscape work.
Richard G
Mentor
I'm likely to be mostly using the PME90 with a longer lens, like the Sonnar 150, which I find the easiest of my lenses to focus with the plain Acute Matte D screen. If I want the height with my 60 I can easily take an incident reading. I guess you don't want to be changing screens much, but the Acute matte D for some particular landscape shot with a 150 or longer could justify the tedium of swapping screens.
Retro-Grouch
Mentor
Good advice, and of course telephotos are always easier to focus. But I'm a wide-angle guy. 80mm is my tele, 60mm my normal, 50mm my wide (I have a 150 that gathers dust). Another reason I want all the help I can get with focusing.
Richard G
Mentor
Yes, the 60 is what I use most. Love the close focus. Usually take the 80 only for its lightness and compactness.
Godfrey
somewhat colored
Since it costs nothing to experiment, I'd do a set of test shots on various scenes with the PME90 and see what it reads, then put the Acute Matte screen that has a focusing aid you want to use into the body and check what it reads on the same scenes. If it is consistently off by some factor, just dial that factor into the film speed and you're done. If you find that it reads differently based on the scene type, well, learn to recognize when the difference will matter and adjust on the fly. 
G
G
Pál_K
Cameras. I has it.
I’ll invoke the Why Not Both meme and suggest using your split image screen for precise focusing (because that’s the more important aspect) and then use a separate spotmeter to take readings.
I use a Pentax spotmeter to make readings of the brightest and darkest parts of my image and, in Zone System fashion, I make readings to decide where I want Zone V to fall.
Think of how much fun and entertainment you can have with this little extra bit of equipment.
I use a Pentax spotmeter to make readings of the brightest and darkest parts of my image and, in Zone System fashion, I make readings to decide where I want Zone V to fall.
Think of how much fun and entertainment you can have with this little extra bit of equipment.
Retro-Grouch
Mentor
The real entertainment will come when our house collapses and sinks into the earth under the weight of all those little extra bits. The whole point of the PME90 was convenience and freedom from toting another meter! Well, that, and having another nifty Hassy trinket. It makes wicked cool beeping noises. Cats come a-runnin'!
Retro-Grouch
Mentor
Since it costs nothing to experiment, I'd do a set of test shots on various scenes with the PME90 and see what it reads, then put the Acute Matte screen that has a focusing aid you want to use into the body and check what it reads on the same scenes. If it is consistently off by some factor, just dial that factor into the film speed and you're done. If you find that it reads differently based on the scene type, well, learn to recognize when the difference will matter and adjust on the fly.
G
Thanks for the tip. I've pretty much done this, and found that the variation is inconsistent, and unpredictable. I do think I'll try some more involved testing in various conditions. However, adjusting on the fly is pretty iffy with color transparency film, and my whole reason for using the spot meter is for the accuracy when shooting with those unforgiving emulsions. Besides, I'm too obsessive to wing it that way!
Richard G
Mentor
Mine is silent! I will have to look into this.
Wenge
Registered User
average it out .after 50 the eyes play tricks, then it gets better
Godfrey
somewhat colored
Color transparency film? I don't think I've shot color film in at least an eon or three (other than Instant Film), never mind medium format transparency film. LOL!
Color transparencies is why I bought a good light meter years ago. I found I could never trust *any* in-camera meter with that stuff. I prefer an incident meter over a spot meter for such work.
Good luck!
G
Retro-Grouch
Mentor
Hmm... I'm twenty years past 50, and still in the "tricks" phase, it seems. Guess I'll just have to be patient!
Retro-Grouch
Mentor
This gets curiouser and curiouser... I just dug out the box my acute matte D came in and discovered the brochure that was packed with it. There, it says that there are no restrictions on using the spot meter in the PME90 within the f/2 - f/5.6 range. After f/5.6, the split image section will black out and confuse the meter. However, the PME instructions indicate against using the spot meter with a split image/microprism screen. Could it be that the later "D" screens resolved the problem, but that the PME90 instructions were printed before the introduction of the "D" screens? Could it be that I'm way overthinking this, and should just shut up, grab my camera, and go shooting? Do I really need to ask that?
Retro-Grouch
Mentor
You can switch it on or off. I leave mine off, since I'm not a cat. Pal_K probably leaves his on, since he is. Or at least he identifies as one, which we should all respect.
Pál_K
Cameras. I has it.
As a cat, I like to play with toys - so the prism on my 500C/M is an older non-metered prism and I use the Pentax spotmeter for all my metering (or Sekonic 308S for averaging or incident).
Although almost all my photography has been with negative film, I did buy a few packs of Provia in medium format based on what I saw from a local photographer - and he just had his work on a light box, not projected. Should be fun - I’m waiting for fall colors.
I trust what your brochure says - let us know how it works!
Richard G
Mentor
If I was as wise as my cat I might not have the compulsion to pursue photography. Have been watching Thomas Heaton YouTube videos. He uses Provia in a 501c for landscape photography. Careful metering with spot meter, metering the sky and adding two stops. That seems to be how my PME90 was set up when I got it.
Retro-Grouch
Mentor
Ok, since you asked! Since today was too hot for man or beast, I stayed inside with two 500C/M bodies, three different screens, two accurate and matching hand meters, a light box, and the PME90. And a lot of cussing. The verdict: as the instructions said, "DON'T!" The split-image microprism screen reads about 2/3 stop high on "spot", and about a half stop low on "average". But it varies depending on light levels, so that there's really no accurate correction factor. Too wonky to use with the meter, so it will get dedicated to my non-metered-prism body.
If I were a cat, all that playing with multiple toys would have been fun. As a mere human, it was tedious and annoying. Perhaps I should let my cat handle all my technical questions in the future.
Pál_K
Cameras. I has it.
So the brochure says no restrictions on using the PME90 with that screen between f/2 and f/5.6, but experiments show otherwise and match what people have said.
I don’t understand - it seems atypical for Hasselblad to have made a mistake like that. But… can’t argue with the results.
I don’t understand - it seems atypical for Hasselblad to have made a mistake like that. But… can’t argue with the results.