Note on focusing screens

This is a very brief, but useful note.

Focusing screen

Focusing screen

When shooting on manual optics, I was confronted with the fact that focusing screens for modern digital SLR cameras are not optimized for working with high-aperture optics.

The vast majority of focusing screens in modern central control centers optimized for use with F / 2.8 lenses and darker. Ultimately, this affects the fact that while working with a faster aperture optics, the depth of field and the blur zone are not as clearly visible as we would like.

The situation is worsened by the use of a pentazer instead of a pentaprism, which makes JVI small and dark.

Real example 1: when using a fast lens Super-Takumar 1: 1.4 / 50 and CZK Canon EOS Digital Rebel XSi (aka Canon EOS DIGITAL 450D, aka Canon EOS Kiss) from JVI on the basis of pentzer mirrors в JVI very, very hard to see how accurately the object is in the zone of sharpness or blur. When you close the aperture to f / 2.8, brightness JVI does not change. With 3000 shots taken through JVI with visual confirmation of sharpness, only 300 pictures (about 10%) turn out to be really correct focus. My experience is that a similar situation happens with other fast lenses when used on cameras with a pentazerkalnoy.

Real example 2: with pentaprism cameras, the situation is much better. When used with super fast Nikon NIKKOR-SC Auto 1: 1.2 f = 55mm lens and DLC Nikon D90 on the basis of a pentaprism it is much simpler to sight and understand that is in the zone of sharpness or blur, but still the process is not comfortable enough. With 1000 shots taken through JVI with visual confirmation of sharpness, only 150 pictures (about 15%) turn out to be with really correct focus. When you close the aperture from F / 1.2 to F / 2.8, the brightness of the scene you shoot in JVI does not change. A decrease in brightness can be seen only when the aperture is closed from F / 2.8 to F / 4, this example just indicates that modern focusing screens are not optimized for working with high-aperture optics.

Whoever does not believe in this, let him try to sight on cameras of the 60s, 70s, optimized for F / 1.4. The difference will be so enormous that it can turn over all ideas about the JVI,

My experience also says that large JVIs with full-format CZKs simplify working with manual optics. As far as I know, some modern Canon CLCs allow the use of interchangeable focusing screens optimized for different tasks.

Material prepared Arkady Shapoval. Training/Consultations | Youtube | Facebook | Instagram | Twitter | Telegram

P.S. Commentators will come running now and tell everyone about replacing screens, wedges, micro-rasters, the death of the JVI, the benefits of the EVI and other useful things.

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Comments: 41, on the topic: Note on focusing screens

  • Alexander

    And I have another question. How to clean the focusing screen? thanks

    • Arkady Shapoval

      In the service center, the answer is approximately the following - to clean it by replacing it with a new one :)

      • Vyacheslav

        Good afternoon. Could you please tell me if it is possible to replace the focusing screen in the Canon 200D with the screen declared as a part for the Canon 450D - 650D? Or from Canon1100? How many I was looking for - only such options came across.

    • Valery

      Alexander, I clean this way, pour distilled water into two tea cups (you can buy it at any auto shop), drip 3-5 drops of “AOC” type detergent into one of the cups, stir, you can use a squirrel brush if it is very dirty tail, and another box from the SD flash drive will be needed as a stand when you take out the screen from the carcass, put it first there to free your hands, take it out with tweezers, put it on, remove the camera to the side, again take the screen clamped with tweezers by the tongue, I take it in left hand, put it in a cup with soapy water and rinse, if necessary use a brush, does not scratch, checked, rinsing thoroughly - carefully and slowly so that the surface tension of the liquid leaves as much moisture as possible in the cup, and not on the screen, take it out and start rinsing in clean water, again very slowly we remove the screen from clean water and begin to blow off the remaining water from the center to the edges with a photogun, believe me, very little of it remains, we do all this on both sides, mo You should put it in a box from a flash drive and blow it out, but carefully, the screen can jump out of the stand from a strong stream of air, blew it out, there is no moisture residue, check the viewfinder for cleanliness, blow it with a pear and put the screen in place, that's it, you have a clean screen / PS. when you clean the viewfinder, remove the adjustment frames, then put it back in, good luck, everything works out.

  • Serge

    That's right, I read about it for a long time and checked it myself. Not many people know about it.

  • izlomdoc

    “P.S. now commentators will run in and tell everyone about the replacement of screens ”
    Still would not run :)
    Say about canon, and keep silent about 90% matching mechanics with the possibility of replacing Nikon.

    • Arkady Shapoval

      I waited until they came running and said for me) checkmate :)

      • izlomdoc

        that is why P.S. heh

    • R'RёS,R ° F "RёR№

      On D3200 I installed a screen with wedges and prisms. At first I thought that I would not use prisms, but it turned out the other way around - with high-aperture optics, it is better to see them out of focus.
      ps screen from Zenith, the toad pressured to pay for the Chinese for the sake of interest.

  • Jury

    I had a case with Kiev 19: the viewfinder is large and bright, the focusing screen is just super - the moment of maximum sharpness is clearly visible, however, after developing the film, it turned out that all the frames were out of focus (I shot with an old manual 180 2,8). Most likely problems with camera alignment. In a modern DSLR, focusing with manual lenses is less convenient, but the fact of poor focus is immediately visible and can be corrected by the next shot. I put a viewfinder with a magnification in the D800, I always use it in 1.08 mode, and when working with the manual I put 1.6, but a screen with a microrastr would also be useful)

    • Boris

      And it is possible in more detail for a viewfinder with magnification, what kind of model? Does it have a zoom? Also on the d800e I would like to enlarge the picture in the eyepiece, otherwise the camera is FF, and the frame in the viewfinder is slightly larger than the crop. And exactly, in the peephole of "Kiev-19" everything looks larger and there is a microraster, which would be useful for both FF and crop

      • Jury

        can :) bought here... The first time you need to get used to it, on the D800 it is screwed in instead of the native eyepiece with an elastic band. At the maximum zoom, the indication goes out of the field of view and you need to select the angle of view in order to see well. Therefore, I always use the minimum zoom. When changing the zoom, you need to adjust the diopters. After some time of use, I returned my native eyepiece in order to understand how better - I immediately realized that it is better with magnification and I don’t take it off anymore, besides, a large rubber band on a non-native eyepiece is more convenient and, most importantly, if I put a manual glass, there is always an opportunity to install zoom 1,6, adjust diopters and shoot a little more comfortable)

    • Onotole

      Something I can’t understand how the OVI can help with the described problem of the impossibility (not difficulty, but impossibility) of accurately focusing on optics lighter than 2.8? This is a structurally embedded bummer.
      From the fact that you enlarge the picture on it, the DOF will not narrow. I’ll allow myself to draw an analogy: if you have a monitor, for example, with a resolution of 1600x1200, then whatever magnifying glasses you bring, even microscopes, you will not get more information than it has already given out, you will not be able to look out any additional pixels. So it is here.

      • Kamil

        By analogy with the monitor, the picture will become clearer if you wear glasses. Or with glasses you can more accurately see its fuzziness.

        that rare case when comments are more useful than notes, write, write more!

      • Jury

        in the OVI, a real “analog” picture is visible, increasing it, we have the opportunity to better examine objects in the frame and better see whether the required object is in focus. The analogy with a monitor is suitable for EVI, but in JVI there are no pixels (if you do not take into account the information screen) and the picture, in principle, can be enlarged for a long time without achieving pixelation). The analogy is appropriate with an ordinary magnifying glass, which we take to see small objects inaccessible to the eye.

  • Vladimir

    And how can they be optimized?

    • Arkady Shapoval

      Modern screens consist of a surface composed of a huge number of identical microprisms, either printed or laser cut. By varying these microprisms, different effects are achieved. Older cells used randomly spaced prismatic grains. + brightness depends on auxiliary lenses above the screen. If anyone can explain more clearly - unsubscribe, my knowledge in this matter is not so deep.

      • anonym

        Arkady, these questions were raised at one time (in the film era) by the famous St. Petersburg optical engineer Pavel Boyarov in his series of articles "Viewfinder and Focusing" ... there will be time - I will find the original source and let you know ...

  • zengarden

    When Nikon was there, I seriously thought about the focusing screen, because I love manual optics. There are (were) good KatzEye screens, but they are no longer available; there are Chinese for 2 thousand rubles, and more advanced, thousand for 7. But in the end I switched to the UPC, and everything is easier and more convenient there - there is focus-picking and imitation of a rangefinder.

  • Lynx

    What kind of cameras in our 70s are sharpened for optics by 1,4 ??

  • Maksim

    I’m shooting on the Nikon D90 + Visionar 109mm 1.6, I use the LCD-V1 viewfinder, purchased for 130 UAH, everything is perfectly visible at maximum screen magnification, visibility as on a monitor screen, I recommend it to everyone.
    The only drawback, I have a +2 vision, I had to put an additional +4 lens.
    The lens is homemade, but even in children sharp pictures are taken, there is no marriage at all.

  • Alexander

    For five years already, I got used to sawing and inserting screens from film cameras into the czk, it is cheaper than Chinese screens and much better, but screens have to be removed from good brands, I took out mummies and boxes, Soviet ones, especially from the zenith - rubbish. No doubt, it greatly facilitates shooting.

    • R'RёS,R ° F "RёR№

      Zenit just for high-aperture optics)))). In low light and (or) small aperture, the wedges stop working, and then the raster.

      • Alexander

        Try from something more decent than the zenith and you will understand the difference, probably worse than the zenith and there is nothing.

        • R'RёS,R ° F "RёR№

          And even with them it is more convenient with manual optics.

          • Alexander


  • Peter Sh.

    I once inserted such a screen in the D90.
    He cursed everything in the world, the clamp clamp holds on to a dead protrusion of soft plastic. The protrusion is easy to mash and scratch everything in the process. The staple is pushed back extremely difficult.

    Maybe this is personally true for me, but keep in mind.

  • Nikola

    You should have seen the ZENIT 3C viewfinder, and whoever saw it will confirm that this is where the viewfinder is, so the viewfinder is a song!
    With a 3.5 50mm lens, the brightness is excellent, there are simply no words for matting: when sighting, you can see the slightest shift in depth of field, and with Helios it is fantastic. At the same time, there are no micro-rasters, wedges - pure frosted glass. Pentaprism with an exceptionally high-quality silver coating, which even now looks like new, and the prism glass itself is nowhere better. After this model, things slowly began to decline. Zeniths with a microrastrom, even without TTL, were useless, and with TTL, even with a keen eyesight, it was sheer anguish - darkness!
    The old Pentaxes, such as the K1000, had good sights, albeit with microrasters.
    By the way, of the current DSLRs, only the Pentax have viewfinders more or less suitable for manual focusing. Why? Good magnification - 0,95x, plus some kind of matting of the raster, you can even see depth of field like that. Although this is not a fountain, there are also many misses. Summary: Current viewfinders are completely unsuitable for manual focusing. And no enlargers can save them. Alas.
    Good luck to everyone!

  • Nikola

    I'm sorry, I made a typo. Not ZENIT 3C, but simply ZENIT S. In the third it is already worse ...

    • Victor

      … Those were the lightest Zenith viewfinders, tk. made conscientiously ...

  • Basil

    A reasonable question - if everything is bad with the optical viewfinder on modern CZK, then how are things not about the electronic viewfinder? Sony 7 series, fujifilm xt-x and more ...

    • Basil

      I live in the outback, I have not seen mirrorless ones :)

      • Nikola

        In the good, right mirrorless, with the viewfinder, everything is fine.
        It's good that it is convenient, even very, in terms of focusing. By and large, they are simply made for non-autofocus optics. Focusing is almost instantaneous and unambiguous, there are practically no misses. You can put anything on them, with any focal length, since there are adapters for any whim - thanks to the ubiquitous Chinese comrades.
        However, the eye is more pleasant to look into the optical, direct vision, mirror viewfinder.
        Mirrorless cameras, even the "entry-level" ones, are too expensive. More roads. Unfortunately, this has been delayed yet.
        When the opportunity comes to buy mirrorless cameras at the price of current entry-level DSLRs, then we will have a holiday, lovers of good old lenses. Until then ...
        Good luck!

        • Nikolay Fedorovich

          If you can't afford 230-250 bucks. then yes, and if available, take the first Yeshka and you will be happy

  • Vsevolod

    Hello, Arkady and Society!
    Canon 70D, standard focusing screen. With manual focusing through the JVI, the focus moment is poorly seen. And the matter is rather in the eyes, and not in aperture.
    What will be more useful: an OVI magnifier or a replacement focus. And which screen to change: ultra-precise or with wedges-prisms? And if prism wedges, how does such a screen affect the correct metering?
    Thank you!
    (glasses, do not offer eye drops.)

    • R'RёS,R ° F "RёR№

      If super accurate, then with a magnifier. With wedges-prisms, focusing will be noticeable in sufficient lighting. There can be problems with exposure - in my case it is impossible to shoot with metering at one central point - there is a border of wedges, which causes a strong overexposure.

  • Maksim

    There are D3100, 18-55 and HELIOS-44M 2/58 (KMZ). Vision is relatively normal. It’s personally impossible for me to focus through the viewfinder even on a whale lens, not to mention the Helios, so I use either autofocus or live view. But the screen is so wretched that you have to enlarge the picture so as not to miss. In general, many are familiar with the situation.
    I really like shooting on manual optics, but dancing with a tambourine is boring, especially when you need to catch the moment.
    After reading the article, he studied the market for focusing screens. An affordable option for me is for sale, on Ali for 2k
    Interested in the opinion of those who already ordered there. What quality, how autofocus and metering behave, are there any better alternatives for the same price?

  • anonym

    Hello. Before shooting in Kiev, I shot only by digital, I liked the viewfinder, compared to the Nikon D19 it’s bigger, lighter and much more convenient to aim. I don’t want to spoil Kiev, I found an ad-focusing screen from it for 3300 rubles. Is it worth taking, or it’s better to see the focus. screens from other cameras?

  • Alexander

    I have a question. How to clean the plano-convex collective lens behind the focusing screen in front of the pentaprism.

    • Alexander

      Experienced guys advise not to touch this business unless absolutely necessary.
      My used one had a scratched outer viewfinder lens. I removed GOI with a cosmetic cotton swab with paste in 10 minutes.
      And the dots on the focusing screen turned out to be scratches, I had to take it more seriously, I killed two days.
      From my own experience, there is always a risk of damaging the screen, frame, etc. etc.
      Do you want it?

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