Accidentally marked my D800 focussing screen

Discussion in 'Nikon' started by tony_gorell, May 10, 2015.

  1. I was cleaning out the mirror box of my D800 with a rocket blower brush (camera held with lens opening facing down) when I accidentally slipped and the plastic tip of the blower brush touched the focussing screen, leaving several marks which appear as grey marks in the viewfinder. Definitely not scratches. The camera is otherwise undamaged and works perfectly well. I was surprised that the plastic left such a prominent mark.
    I know that the screen can be replaced, and know how to to that. It is delicate, but the cost of a new screen is exorbitant here in Australia.
    It's more of a nuisance that anything else. I used it for several hours today and readily adjusted. After a while, I didn't really notice it anymore, but...
    Has anyone experienced this and know of a way to remove the marks? Would isopropyl alcohol work, or would it further damage the screen?
  2. In my experience, cleaning the matte side of the focusing screen is difficult (unless it is merely with air) and if you use liquid, it is likely to leave some residue in the pores of the screen. If the marks bother you I would have the screen replaced in service, or you can buy a 3rd party screen which may have some advantages (for manual focusing).
    I nowadays use a vacuum to clean the mirror box, as it leaves the mirror box clean for a much longer time than blowing air into the box, which just moves it about and puts it into places where it shouldn't go. However with vacuum you also have to be careful so that the tip of the instrument doesn't get into the box and damage something. Also too much flow can be dangerous.
  3. Isopropyl alcohol will not damage your screen.
    The marks could be plastic from your blower deposited onto the screen in which case you might be able to remove it. Or it could be a depression in your focusing screen in which case you can't remove it.
    You really have nothing to loose. If it doesn't work out you just have suck it up and get a replacement screen. Sometimes ordering from other parts of the world will be cheaper. As long as you get a Nikon original screen it makes no difference where it comes from.
  4. Personally I wouldn't attempt an alcohol clean of the screen in place. During the course of cleaning up several SLRs with
    removable screens, i found that alcohol often left smearing on the matte side of the screen that took quite a lot of work to
    finally remove. And that was with the screen available "in hand". I can't imagine successfully doing this working through
    the lens mount. I would leave well enough alone. That being said, if you do go ahead, use reagent grade alcohol, not
    anything you get in a store or pharmacy - the consumer stuff contains sufficient crap that will leave " tide marks" on the
    screen as it evaporates
  5. I'm guessing by looking at photos that it's the similar plastic screen like other similar Nikons. If this were me, I would
    remove the screen, put it in a small bowl of warm water and dish soap, mop both sides with either a sable or squirrel hair
    brush, blow dry it with cool/warm air from the blow dryer. Don't rub the Matt side with anything, just mop it and air dry it
    clean. For over a decade I worked as an industrial photographer and my screens were always dirty after a while, this is
    how I cleaned them numerous times. The big Bronica SQ screens were always full of crud.
  6. If you've adjusted to it I think it may be best left alone. The above suggestions may work well and may make the problem worse. You don't know until you try I guess but if it were mine I'd quit while I was ahead.

    Rick H.
  7. ShunCheung

    ShunCheung Administrator

    It's more of a nuisance that anything else. I used it for several hours today and readily adjusted. After a while, I didn't really notice it anymore​
    When I was in my 20's, I was obsessed about keeping my SLRs' focusing screen clean. And every time I tried to clean the focusing screens, I made it worse, either leaving more scratch marks or liquid residues .... Eventually I learned my lesson and left it alone. If you can tolerate it, that is your best option.
    If it is not tolerable, please try to clean it a safe way as suggested by the experienced folks above or just buy a new screen. Keep in mind that the D800's focusing screen is held in place by a metal wire. If you are not careful, you can potentially displace the wire from its holes, and it is going to be very difficult to put the wire back in place into those little holes within the confine of the mirror box with the delicate mirror around.
    Yes, it is very much possible to make it a lot worse, e.g. damaging the mirror.
  8. May be that is why I love camera with interchageable viewfinder as the focusing screen can be replaced so easily.
  9. ShunCheung

    ShunCheung Administrator

    May be that is why I love camera with interchageable viewfinder as the focusing screen can be replaced so easily.​
    Certainly. I have an F4, F5 and a Contax 645, all with interchangeable viewfinders. While that option does make it easy to change the focusing screen, I have to confess that I have never bought even one optional viewfinder (other than the ones that came with the cameras), mainly due to the high cost. So it ends up being an expensive way to make it easy to change focusing screens.
    Of course in these days mirrorless is an option such that we get rid of the entire mirror box, focusing screen ... mechanism altogether, and cameras become simpler devices with fewer mechanical parts to break. However, at least for me, currently I still prefer the optical viewfinder. Maybe my preference will change down the road as technology improves.
  10. "Has anyone experienced this and know of a way to remove the marks?"
    Lucky for you the D800 is an AF camera so it should not affect the focusing.
    I went through several focusing screens while tying to replace the screen on my Manual Nikon FE2. The replacement screen for those cameras was only $25-$35 brand new and about $20 used from eBay. Not sure about the D800...
    Believe me I tried all sorts of thinks from using a vinegar dipped Qtip, to dipping the entire screen in warm water to try to get the scratch marks off, but those things did not work and actually made matters worse.
    The reason is (at least for the FE2) they are not actually 'scuff marks' its more like if you scratched one of the lines on your fingerprint. Once its scratched it's scratched.

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