Nikon D3100 mark on mirror/viewfinder?

[Bensch]

While out shooting yesterday, I noticed a mark through the viewfinder that I haven't noticed while I've owned my D3100.

I attempted to clean the mirror with my brush, but can't seem to budge it, it almost looks like a really small hair.

Here is a picture of it, I've circled the mark (there are a couple of other bits on the mirror that need brushing again, but mainly worried about the circled one).

IMG20170815104648 by andrewbensch, on Flickr

I know that the sensor is clean, as it only shows up through the viewfinder, and not on the finished photo.

Can someone confirm for me that it is a piece of rubbish that has perhaps has worked it's way up under the pentaprism (?) glass?

Thanks everyone

[J.davis]

I had some rubbish in my D750. Was, (I believe), from cleaning out with a brush. Cleaned out with compressed air and all good now.

[Bensch]

I had some rubbish in my D750. Was, (I believe), from cleaning out with a brush. Cleaned out with compressed air and all good now.

Thanks John, greatly appreciated.

I have cleaned it with a rocket (bulb) blower from my cleaning kit, the other marks have disappeared, but unfortunately this one still remains

[Plays With Light]

Must fess up that the first time this happened to me on my first DSLR, I made the horrific mistake of blowing on it and ending up with all manner of crap on there! I quickly had the sensor cleaning swabs out and brought it back to life very quickly.

[ameerat42]

This looks as if it could be (?some evaporation stain) on the same surface as those
registration marks. You might not be able to get it off without some major dismantling,
but if you're lucky that may also be a removable (interchangeable) screen.

(Sorry. Not very constructive.)

[arthurking83]

First thing I recommend if not to use a rocket blower.
You usually blow more dust on the surface than you remove.
Canned air is much better, as in ... it's clean! But note that you never shake a can of air before use as it will agitate the propellant.
The propellant does wipe off, but you don't want it on there to begin with.

Going by that image, it could be a small speck has got into the focusing matte. I've had that on all three of my DSLRs at some point.
So if you've blown the mirror and it hasn't gone then the only other place it could be is the focusing matte.
Hopefully it's just stuck harder on the bottom(outside) surface, and blowing again from inside the mirror box up into the viewfinder will move/remove it.

If you try that, and it doesn't move at all, then it's inside the focus matte. You can see it(the focus matte) if you tip the camera upside down and look up into the viewfinder area.
It's an opaque looking piece. Note that it's only plastic and can be scratched quite easily. But if you have a steady hand, it's very easy to remove it and replace it.

If you haven't already tried to use a brush or air on the outside surface of the focus matte(ie. that facing the mirror) then I'd suggest a few other options:

Something that you can try before that tho is to tip the camera on a side that places the viewfinder matte screen in the vertical position. ie. orient the camera so that the review LCD screen is facing down .. or that the lens/lens mount is facing down.
Then you give the viewfinder housing on the camera(ie. near the flash hotshoe) some thumping with your open palm.
The idea being that the sharp motions on the camera will try to dislodge the small dust particle, and that if the surface of the matte screen is vertical it will hopefully fall off.
Sometimes it works, sometimes it doesn't.
Note that this is hit and miss because the focus matte is plastic and dust can have a static charge ... static charge and plastics go well together .. to our dusty annoyance!

Many moons ago I had written up a tute on how to remove the focus matte on a Nikon. (do a search on 'focus matte' or 'Katzeye screen' or whatever, hopefully it comes up in the results)
It's very easy, but you need a steady hand.
You can use a tiny jewellers long nose pliers, but you have to be 99.99999% cautious that you don't slip on the retaining clip.
All Nikon cameras use the same matte retaining system, they only vary in where the bent section of the retaining clip is located, and it's not easily seen.

[Bensch]

Must fess up that the first time this happened to me on my first DSLR, I made the horrific mistake of blowing on it and ending up with all manner of crap on there! I quickly had the sensor cleaning swabs out and brought it back to life very quickly.

Thanks Alex, I've picked up some sensor cleaning swabs, hopefully they do the trick.

This looks as if it could be (?some evaporation stain) on the same surface as those
registration marks. You might not be able to get it off without some major dismantling,
but if you're lucky that may also be a removable (interchangeable) screen.

(Sorry. Not very constructive.)

Thanks

Doing some googling and I came across this video on removing the focusing screen on a D40, but it looks the same as Arthur mentioned.

Might try the canned air and sensor swabs first, and if that doesn't fix it, might have to remove the focusing screen and see if it has worked up under there.

First thing I recommend if not to use a rocket blower.
You usually blow more dust on the surface than you remove.
Canned air is much better, as in ... it's clean! But note that you never shake a can of air before use as it will agitate the propellant.
The propellant does wipe off, but you don't want it on there to begin with.

Going by that image, it could be a small speck has got into the focusing matte. I've had that on all three of my DSLRs at some point.
So if you've blown the mirror and it hasn't gone then the only other place it could be is the focusing matte.
Hopefully it's just stuck harder on the bottom(outside) surface, and blowing again from inside the mirror box up into the viewfinder will move/remove it.

If you try that, and it doesn't move at all, then it's inside the focus matte. You can see it(the focus matte) if you tip the camera upside down and look up into the viewfinder area.
It's an opaque looking piece. Note that it's only plastic and can be scratched quite easily. But if you have a steady hand, it's very easy to remove it and replace it.

If you haven't already tried to use a brush or air on the outside surface of the focus matte(ie. that facing the mirror) then I'd suggest a few other options:

Something that you can try before that tho is to tip the camera on a side that places the viewfinder matte screen in the vertical position. ie. orient the camera so that the review LCD screen is facing down .. or that the lens/lens mount is facing down.
Then you give the viewfinder housing on the camera(ie. near the flash hotshoe) some thumping with your open palm.
The idea being that the sharp motions on the camera will try to dislodge the small dust particle, and that if the surface of the matte screen is vertical it will hopefully fall off.
Sometimes it works, sometimes it doesn't.
Note that this is hit and miss because the focus matte is plastic and dust can have a static charge ... static charge and plastics go well together .. to our dusty annoyance!

Many moons ago I had written up a tute on how to remove the focus matte on a Nikon. (do a search on 'focus matte' or 'Katzeye screen' or whatever, hopefully it comes up in the results)
It's very easy, but you need a steady hand.
You can use a tiny jewellers long nose pliers, but you have to be 99.99999% cautious that you don't slip on the retaining clip.
All Nikon cameras use the same matte retaining system, they only vary in where the bent section of the retaining clip is located, and it's not easily seen.

Thanks Arthur

I'll pick up some canned air in the next few days, and give it a shot when the swabs arrive.

Tried giving it a light tap, but unfortunately it is still in exactly the same spot.

I googled exchanging it and it looks quite easy, as long as I'm really careful, you can actually buy kits to exchange it with another one, any thoughts on adding/upgrading to a 180 split image focusing screen?

[arthurking83]

....

I googled exchanging it and it looks quite easy, as long as I'm really careful, you can actually buy kits to exchange it with another one, any thoughts on adding/upgrading to a 180 split image focusing screen?

If you have the odd manual lens .. for sure.
BUT!! not an ebay one. Less useful than a bulb blower in space!
I got one for my D70s years back(still have it I think) but removed it after pushing myself to like it for a while.

Katzeye no longer exist, and I'd highly recommend one if they still did.
But as of current, the focusingscreen.com screens are pretty good. Not as good as Katz were, but still usable.
I ended up with their S-type for my D800E, but it's just a bit too dim, even tho it's miles more accurate when focusing a fast f/2 or faster lens.
It just darkens up too quickly.
I'm planning to try out one of their K type screens one day with the diagonal split screen and see how that works on the D800E.

Oh! .. sorry, reason the ebay screens don't work well is exposure will be all over the place sometimes, and split screen darkens badly at f/5.6. So most consumer lenses don't work well at all.

[CathyC]

thanks for the PM Andy - sorry I couldn't offer any more advice other than what is noted here
needless to say, you had me grabbing my camera and having a closer look - and I noticed all sorts of tiny little 'hairs' that I hadn't noticed before.
I believe they are in the view finder, as they do not appear to be on any of my images LOL

[Bensch]

If you have the odd manual lens .. for sure.
BUT!! not an ebay one. Less useful than a bulb blower in space!
I got one for my D70s years back(still have it I think) but removed it after pushing myself to like it for a while.

Katzeye no longer exist, and I'd highly recommend one if they still did.
But as of current, the focusingscreen.com screens are pretty good. Not as good as Katz were, but still usable.
I ended up with their S-type for my D800E, but it's just a bit too dim, even tho it's miles more accurate when focusing a fast f/2 or faster lens.
It just darkens up too quickly.
I'm planning to try out one of their K type screens one day with the diagonal split screen and see how that works on the D800E.

Oh! .. sorry, reason the ebay screens don't work well is exposure will be all over the place sometimes, and split screen darkens badly at f/5.6. So most consumer lenses don't work well at all.

Thanks Arthur

I only have AF lenses (at the moment) but thought that it would be something interesting/different.

Might look at getting one from focusingscreen a little later, will try cleaning my current one first and see how I go.

thanks for the PM Andy - sorry I couldn't offer any more advice other than what is noted here
needless to say, you had me grabbing my camera and having a closer look - and I noticed all sorts of tiny little 'hairs' that I hadn't noticed before.
I believe they are in the view finder, as they do not appear to be on any of my images LOL

Thanks Cathy

I was thrown in that it is the same darkness, and thickness as the lines around the AF points. Thought that I'd enquire to see how it stacked up against another D3100.

It's not a major thing, but am a little OCD, and now that I can see it, it really bugs me



Have ordered a pair of rubber tipped tweezers (so I don't scratch anything) and once they have arrived (along with the swabs) I will remove the screen and give it a clean.

[Bensch]

Hi everyone, a quick update in my adventures with the hairy viewfinder.

Swabs and coated tweezers arrived, and I took the focusing screen out and cleaned. Reassembled and the hairy was still there

Went and purchased a can of compressed air, removed the screen again, and gave it a clean out.

Reassembled and me being me, managed to put not one, but three large scratches on the screen (didn't even realise that I slipped!)

Ordered a replacement screen which arrived on the slow boat last week, replaced the screen, and.....

There's another hair......well, it can stay there

[arthurking83]

....

Reassembled and me being me, managed to put not one, but three large scratches on the screen (didn't even realise that I slipped!)

Ordered a replacement screen which arrived on the slow boat last week, replaced the screen, and.....

There's another hair......well, it can stay there

LOL! I'm the same .. bit of a clutz(I think) .. not sure.

With my D300 I got a Katzeye for it. Removed old screen, put it on cloth and noticed a large hair like mark on it .. thinking a hair. Nope a scratch.
There was no scratch on it when I took it out, When I remove mine, I use a pec pad on the mirror, and turn camera right side up so it falls gently on the pec pad. No damage there.
I know I didn't slip unclipping the retainer clip .. so how it got scratched is

They have a locating tab at one side of the rectangle. this is used so that it sits properly in the camera .. is a good place to use tweezers on too

Did you order a standard screen replacement or a 'better one'?
That's the one thing I keep forgetting to do, is to order a K-type screen for the D800 too .. maybe with some simple aids(microprism maybe .. not sure).

Last note on the hair in there annoyance. if you tried canned air, when you spray in the camera vf head area with screen out, are you holding camera upright(normally) or upside downly so that you can see it easily.
if upside downly(with top of camera pointing down) try it topside up .. as normal orientation.
Could be blowing hair around the vf chamber rather than out of it.
And of course the important reminder that the mirror surface is fragile and can be damaged easily so keep straw of canned air away as best you can.

[Bensch]

LOL! I'm the same .. bit of a clutz(I think) .. not sure.

With my D300 I got a Katzeye for it. Removed old screen, put it on cloth and noticed a large hair like mark on it .. thinking a hair. Nope a scratch.
There was no scratch on it when I took it out, When I remove mine, I use a pec pad on the mirror, and turn camera right side up so it falls gently on the pec pad. No damage there.
I know I didn't slip unclipping the retainer clip .. so how it got scratched is

They have a locating tab at one side of the rectangle. this is used so that it sits properly in the camera .. is a good place to use tweezers on too

Did you order a standard screen replacement or a 'better one'?
That's the one thing I keep forgetting to do, is to order a K-type screen for the D800 too .. maybe with some simple aids(microprism maybe .. not sure).

Last note on the hair in there annoyance. if you tried canned air, when you spray in the camera vf head area with screen out, are you holding camera upright(normally) or upside downly so that you can see it easily.
if upside downly(with top of camera pointing down) try it topside up .. as normal orientation.
Could be blowing hair around the vf chamber rather than out of it.
And of course the important reminder that the mirror surface is fragile and can be damaged easily so keep straw of canned air away as best you can.

Thanks Arthur

I ordered a standard replacement for the moment, will more than likely leave it as a standard and put a "better one" in on the upgrade, when I purchase one.

Am travelling at the moment, but will disassemble it when I return home and clean it out again. I thought that I could live with it, but after this morning's ranting about the hair, it appears that I can't