Split-image vs microprism screen

[jaehoppa]

Has anyone used both types of screens? What do you guys prefer?
Which one is better for portraits? Trying to find the split image screen for the Pentax 67II but so hard to find. I wonder if it's worth getting it over the microprism.

 

[Leigh B]

I prefer a split-image for any scene with a nice straight line at the desired plane of focus for a target.
Obviously you can rotate the camera to make the line perpendicular to the split.

For subjects lacking a straight line, I prefer a microprism.

- Leigh

 

[Poisson Du Jour]

Matte field or microprism (not split type) on Pentax 67.
Old cameras require the photographer to adapt to them, rather than the camera adapt to the photographer. The presence of a microprism alone as a criteria should not be the deciding factor on a camera, or any camera.

Focusing on the matte field is a skill worth taking on and is surprisingly precise and often faster than the fiddly microprism. Any small errors in focusing can be taken care of by depth of field. Obviously that isn't always the case in portraiture working at shallow apertures, but it is the case in landscape.

 

[Jim Jones]

I usually prefer a microprism over a split-image screen in a SLR, despite decades of using rangefinder cameras. However, when possible there is usually a plain matte screen, perhaps with parallel lines, in my camera. All three systems can work well, depending on experience and personal preferences.

 

[Paul Howell]

I have both for Kowa, I generally prefer the split image .

 

[paul ron]

i prefer having a split image screen so i can use it as my starting point. then i make some fine adjustments using the peripheral area of tge screen to adjust for my selection of dof preference in composition.

its an extra tool you have at your becon call when and if you need it, its not mandatory to rely on as the final word.

split screens generally have the split rangefinder in the center usually surrounded by a dot micro prism and the rest of the screen is plain with a grid reference.... a nice bag of tools!

 

[thuggins]

As the standard OM screen has a split image surrounded by a microprism, this provides a great opportunity for comparing both side by side. After years of shooting OM's I've come to the conclusion that the split image is much easier to use. Using a microprism requires very good eyesight to determine when the prism area is in focus. In fact, I believe a matte screen is easier to focus on than a microprism because there the whole image is available for focus. Having recently run a few rolls thru my Pen FT with its microprism I can attest that getting the focus right requires quite a bit of effort and concentration.

 

[wiltw]

I think that what your FIRST SLR had will have a lot to do with individual preference. My first two SLRs (Topcon Auto 100, OM-1MD) had microprism center. My next two (OM-1n, OM-4) came with a horizontal split with microprism surround, which presented the advantages of both split image and microprism depending upon subjectmatter. And I have fitted a diagonal split with microprism surround to my medium format SLR (Bronica ETRSi).

I find that the microprism is what I prefer especially for subjects that present no straight lines. Unlike the thuggins comment, I find that I like microprisms because I watch for a slight 'shimmer' to indicate out of focus with microprism. This is quite visible even in 'complex' areas, as well as in lower light levels where it is difficult to perceived any 'split' in a subject line. And in spite of the fact that being 20 years past 45 makes my reading vision compromised without assistance and there is no diopter adjustment to the OM-1n eyepiece, I can still focus via the 'shimmer' better than the split even today, and also much much better than using the groundglass general area especially in low light.

 

[benjiboy]

It depends on the subject and what lens I'm using, I like a microprism for portraits and a split image for wide angle lenses. Some screens have both like the Canon E Screen.

 

[Mr Bill]

An interesting thing I tested, back some 30-ish years ago, was a comparison between a plain groundglass and a split-image screen. The setup was for a chain studio operation; long roll cameras with a locked-down focus point. Whenever a camera was replaced, a technician would reset the focus using a special "focus tool." The tool was installed in place of the film magazine, and basically included a ground glass with magnifier. Once the lens was focused and locked down, the film magazine was put back on.

Anyway, we had a lot of complaints from techs about the precision of this method, and they were never certain if they had it nailed. So we looked into the possibility of switching to a focus screen with a split-image insert in the center. I oversaw some of the trials, and everyone was thrilled with how precise and positive the new tool was. But there was some corporate resistance to spending the money to retrofit all of the tools.

I set up a test to "prove" how much better the split-image screen was. I had something upwards of a dozen people, semi-randomly borrowed from our lab, and asked them to focus the camera in a test studio. My method was basically to mark the final focus position of the lens for each person, such that I would be able to draw a graph of focus-position vs how many people ended up there, it was essentially a histogram crudely showing a statistical distribution. And they also noted how confident they were that they had it nailed.

The results showed that one tool was clearly superior - the results were much tighter centered. But. . . it was the wrong tool. I figured I had mislabeled my tracking sheets, but . . . this had to be verified. So I got all the same people to come back and refocus. Same results. The plain groundglass was clearly superior to the split-image screen with regard to everyone ending up close to the same position. Although nearly everyone was convinced that they did better with the split-image, the opposite was actually true. I have no idea how to explain the mechanism at work, but after that I was always skeptical about the accuracy of a split image focusing screen. (My purpose, on the job, was to "prove" that it was worthwhile to spend some money, but after failing to do so, we just stayed with the existing tools; there was no justification to investigate further.)

To this day, it's still a question that sits somewhere in the back of my mind, waiting to be explained. But in the meantime, I try to use the plain groundglass part of the screen, even though it "feels" less precise.

 

[flavio81]

For me, if the viewfinder is big enough, a plain matte screen is the best.

For the Mamiya RB67 i have the plain screen and the split-image screen and the plain screen is much better for the reasons explained above.

But on a Nikkormat EL i have the microprism screen and it is not so easy to use as the split-image on my former Nikkormat FT2, because these machines have a smaller, dimmer screen.

On a Nikon F3 i had the option of a plain matte screen and it was more or less easy to focus with it. The F3 and F2 viewfinders are bright and big.

On the Canon New F1, which has a remarkably bright viewfinder, i also have a plain matte screen and it's easy to use.

On my Canon "old" F1, which has a slightly dim viewfinder, i have the option of microprism and split-image, but haven't made up my mind on which is best.

On my Spotmatics i have the microprism by default and for some reason, in those machines, it is very very easy to use.

What I can say is that Microprism appears to be more precise than split-image. Plain matte also appears to be more precise.

An interesting thing I tested, back some 30-ish years ago, was a comparison between a plain groundglass and a split-image screen. The setup was for a chain studio operation; long roll cameras with a locked-down focus point. Whenever a camera was replaced, a technician would reset the focus using a special "focus tool." The tool was installed in place of the film magazine, and basically included a ground glass with magnifier. Once the lens was focused and locked down, the film magazine was put back on.

Anyway, we had a lot of complaints from techs about the precision of this method, and they were never certain if they had it nailed. So we looked into the possibility of switching to a focus screen with a split-image insert in the center. I oversaw some of the trials, and everyone was thrilled with how precise and positive the new tool was. But there was some corporate resistance to spending the money to retrofit all of the tools.

I set up a test to "prove" how much better the split-image screen was. I had something upwards of a dozen people, semi-randomly borrowed from our lab, and asked them to focus the camera in a test studio. My method was basically to mark the final focus position of the lens for each person, such that I would be able to draw a graph of focus-position vs how many people ended up there, it was essentially a histogram crudely showing a statistical distribution. And they also noted how confident they were that they had it nailed.

The results showed that one tool was clearly superior - the results were much tighter centered. But. . . it was the wrong tool. I figured I had mislabeled my tracking sheets, but . . . this had to be verified. So I got all the same people to come back and refocus. Same results. The plain groundglass was clearly superior to the split-image screen with regard to everyone ending up close to the same position. Although nearly everyone was convinced that they did better with the split-image, the opposite was actually true. I have no idea how to explain the mechanism at work, but after that I was always skeptical about the accuracy of a split image focusing screen. (My purpose, on the job, was to "prove" that it was worthwhile to spend some money, but after failing to do so, we just stayed with the existing tools; there was no justification to investigate further.)

To this day, it's still a question that sits somewhere in the back of my mind, waiting to be explained. But in the meantime, I try to use the plain groundglass part of the screen, even though it "feels" less precise.

Great post!!

 

[Alan Gales]

On a 35mm camera I like a split screen with micro prism collar. I feel it's the most versatile.

Wiltw brings up an interesting opinion about your first camera dictating what you like. I started with a split screen with micro prism collar.

 

[narsuitus]

My first SLR had a microprism focusing aid that I did not like. However, I did not have the option of changing the focusing screen.

My second SLR had interchangeable focusing screens. I selected a screen with matte focusing aid and loved it.

When my eyesight began to fail from old age, I was forced to change from the matte screen to a split-image screen in order to obtain fast and accurate focusing.

One screen that I really like is a Beattie screen with split image, matte, and microprism focusing aids.

 

[jgoody]

And in spite of the fact that being 20 years past 45 makes my reading vision compromised without assistance and there is no diopter adjustment to the OM-1n eyepiece

Off topic but there are various Nikon Eyepiece Diopters that fit the OM 1 and 2 eyepiece. For me they really help. The ones that fit are for the old Nikon FG/EM (avail ebay), now sold as eyepiece diopter model DK20C (avail BH etc.) - which are identical. For me they have been a big improvement. The only downside is that you have to slide them up a few mms before you open the camera back.

 

[AgX]

One issue that has not been addressed explicitely so far is speed.

It may be that one focusing means yields most precision, but takes a long time to probe, whereas another means may yield a good result in in a second or so.
Just a thought.

 

[dpurdy]

I have a Beattie split image screen in my P67 and have no complaints at all... though I do have a +1 diopter in mine. In my Rolleiflex I have a Maxwell screen with split image and micro prism collar. I use mostly the split image but also check the microprism, I am not in a hurry when I shoot.

 

[Alan Gales]

On a 35mm camera I like a split screen with micro prism collar. I feel it's the most versatile.

Wiltw brings up an interesting opinion about your first camera dictating what you like. I started with a split screen with micro prism collar.

I forgot that I was in the medium format section.

The larger the format the less I find that I need split screens and micro prisms. I liked them on the Hasselblad but not on an RZ67. The larger the ground glass the less I need the help and prefer a more uncluttered view.

 

[Mr Bill]

It may be that one focusing means yields most precision, but takes a long time to probe, whereas another means may yield a good result in in a second or so.
Just a thought.

Yes, this can be an important issue. If you have a split-image screen, and the right subject edges showing, you can simply look for a straight line thru the split-image portion - if it is so, you know that you are right on the money; there is no need to fiddle with the focus adjustment. But with a plain groundglass there is no way, to the best of my knowledge, to be sure that you have the best focus unless you dial past that focus point in both directions, then gradually converge on a best position somewhere between your out-of-focus excursions.

But it mostly depends, I think, on how one likes to work. As an example, some of my heaviest shooting experience has been in high volume portraits, where I shot roughly 40 to 50 thousand different people. This was on 70mm film, camera on a moveable stand with a geared head for precise framing adjustments; every shot was reframed then refocused before shooting. Back in the day, this was done to keep printing costs low - no reframing was done at the printer. In this working model it was not feasible to use a split-image screen because nothing is guaranteed to line up by chance. So my fellow shooters and I used a plain screen to focus on the subject's eyes, and this was actually faster than it would have been to use a split-image screen.

In a different sort of shoot scenario, using a handheld camera without precise framing demands, I can see where a split-image screen might be faster.

 

[jaehoppa]

Thanks everyone for chiming in. I managed to find a split screen with grids for my P67ii (although I'd rather not have the grids).

Does anyone know if split image screens for P67ii have microprism collar around it?

Lastly, it seems like most screens (if not all) are "matte". Why is that? Wouldn't clear screens be better for focusing? I'm probably missing something big here so please let me know. Thanks.

 

[Gerald C Koch]

There is one serious problem with the split image screen. Once you get away from the standard focal length lens one sides of the prism goes black. You can see one side or the other depending on the position of your eye. This effects its usefulness.

 

[Trask]

Gerald -- I don't think it's the focal length that is critica, but the size of the largest aperture setting. It is the case that most normal 35mm-format lens are f/2 or f/1.8, 1.7, 1.4 etc. A 35mm-format 200mm telephoto lenses are more likely to be f/3.5, f/2.8 if you're lucky. In my experience in the latter cases that part of the split image may darken; if I use my 135mm f/2.5 or 200mm f/3 lenses, no darkening.

To the general topic: I have both microprism and split-image cameras, and greatly prefer split-image. It was only recently, when I got a Konica Auto Reflex (the full-frame/half-frame camera), that I found a camera with a microprism central spot that I liked. Other factors come into play, though. About 12 years ago I attended a wedding, bringing my Contax 167MT with 28-85 Zeiss zoom, and tried to take some flash pictures of people dancing in the evening. Impossible to focus in the low light -- just couldn't tell with any accuracy where the lens was focusing (what a split-image). This drove me quickly toward much greater use of rangefinder cameras which, with my 65-year-old eyes, provided much more assurance as to final focus.

 

[phass]

There is one serious problem with the split image screen. Once you get away from the standard focal length lens one sides of the prism goes black. You can see one side or the other depending on the position of your eye. This effects its usefulness.

I use and prefer to focus with microprizms. I actually use the above property of split image screen during focusing. I have split image and microprizm collar screen on my 500 c/m and always make sure that I see the both halves of the split screen before I start focusing with microprizms.
Cheers

 

[John Koehrer]

You can't focus on a clear screen. But if you take the clear screen and add a
+ or other reference to the center. You can focus on the aerial image. Don't they do that
in astronomy?

Someone made a focusing magnifier that did this. I was never able to use the thing.
I guess there's a bit of a learning curve.

 

[Mr Bill]

Lastly, it seems like most screens (if not all) are "matte". Why is that? Wouldn't clear screens be better for focusing? I'm probably missing something big here so please let me know. Thanks.

Hi, well a clear screen would definitely give a brighter, clearer image, but unfortunately no indication of the focus. Your eye would just try to focus on whatever image is coming through, regardless of whether it would be in focus on the film or not. The situation is demonstrated by a pair of binoculars; if you have one, try to focus precisely on some objects. You just can't do it; there is a range of adjustment settings where your eye will still be able to see sharp detail.

Once you put a matte screen in place, it's sort of a "line in the sand." The image ends there; the light coming through is scattered, and can no longer be refocused by your eye (or any other optical system). As long as the matte screen is in the same virtual position as the film, it's a pretty foolproof way to show the degree of focus that will be on the film.

 

[jaehoppa]

hmm I didn't know you can't focus on clear screens. Good to know.