Mirror Cleaning

[psionic]

What method to people use to clean dust bunnies off their mirror ?

A Giotto Air rockets seems a logical choice but I'm wondering if there are other methods ? Sable hair brush ?

/M.

[birddog114]

What method to people use to clean dust bunnies off their mirror ?

A Giotto Air rockets seems a logical choice but I'm wondering if there are other methods ? Sable hair brush ?

/M.

What's the mirror and where? or the CCD?
With the CCD:
Dry method with Giotto Air Rocket and it's worked 90% of the time.
Wet method: Pec Pad and methanol is the only way to treat if the dry method is not working.

[psionic]

[/quote]

What's the mirror and where? or the CCD?
With the CCD:
Dry method with Giotto Air Rocket and it's worked 90% of the time.
Wet method: Pec Pad and methanol is the only way to treat if the dry method is not working.[/quote]

Item 2 in the following cross sectional picture.

http://en.wikipedia.org/wiki/Single-lens_reflex_camera

/M.

[kipper]

Statically charged brushes scare me

Especially seeing as they can hold dust/dirt. Plus have metal where the brushes are attached to the shaft. It scares me to think what would happen if you lose concentration and slip

Or a family member comes in and jokes around and knocks your arm or something while you're doing it.

[avkomp]

I ordered one of those brushes just in case, but prefer the copper hill ccd method. who knows one day I may try the brush but the eclipse and pecpad method just works.

Back to the original question though. What makes you think you have a dusty mirror?? Is it because you have dust bunny spots on your pictures??
If so this will be the ccd which is dirty.
If there is dust visible when you look thru the viewfinder, it is most likely on the focus screen. Dust on the mirror will just blow off with any blower brush but shouldnt cause dust to be visible in the viewfinder, and wont cause dust specs on your images.

Perhaps you could tell us why you think the mirror is dirty and someone will surely be able to help you.

Steve

[gstark]

On the mirror?

Just a giotto.

Dust bunnies on your mirror will have no effect upon your camera's output, and can basically be ignored.

[Dug]

My view screen looks like a potato farm, dirt everywhere, don't sweat it and don't clean it. A mate just cleaned his and ended up with a $250 bill for repair to the AF system

dust on sensor, clean.

dust on mirror, just plant something pretty.

[avkomp]

My view screen looks like a potato farm, dirt everywhere, don't sweat it and don't clean it. A mate just cleaned his and ended up with a $250 bill for repair to the AF system

dust on sensor, clean.

dust on mirror, just plant something pretty

yep!! what he said

Steve[/quote]

[Onyx]

My view screen looks like a potato farm, dirt everywhere, don't sweat it and don't clean it. A mate just cleaned his and ended up with a $250 bill for repair to the AF system

WTF? The AF system (at least in the D70) is located on the bottom of the mirror box, while the replaceable viewing screen is atop the prism. I don't get it... it's like a radiator hose being blamed for exhaust problems.

[DaveB]

I would suggest that dust on your mirror SHOULD be cleaned off.
Otherwise it will migrate to your sensor.

HOWEVER, the alignment of the mirror is very sensitive. A carefully-used blower should be enough, and if not then methanol on a PecPad used VERY gingerly could be used.

If you stuff up the alignment of the mirror, the image reflected up to the focussing screen (and thus to the exposure sensors in the prism etc) will be slightly off. But the AF system will also be affected.
The mirror is partially transmissive: some of the light goes through it and hits a smaller mirror hanging off the back of the main one, and then bounces down to the AF sensors in the bottom of the mirror box. A small alignment issue can mean the AF sensors are *way* off.
The secondary mirror folds up into the back of the main mirror when the mirror is up, so it's very hard to see. But it is there.

[gstark]

... it's like a radiator hose being blamed for exhaust problems.

You've obviously not owned any car built to address the US (California, in particular) emissions standards of the mid 70's.

[gstark]

The mirror is partially transmissive: some of the light goes through it and hits a smaller mirror hanging off the back of the main one, and then bounces down to the AF sensors in the bottom of the mirror box.

If you look carefully at the central section of the mirror, you can actually see the partially transmissive secion. It appears to be darker (or a slightly different colour) and it's a rectangular section pretty much dead center in the mirror.

[psionic]

Basically its the dust bunnies in the view finder that offend me.

Looking at the mirror you can see the odd speck but the buggers seem to like where they have landed and are hanging on tight. Hadn't thought they could also be hanging on to the upper focussing screen.

I have to admit to being a bit nervous opening up the gizzards of my camera last night to get a look at the sensor... but having Fozzie sitting at your kitchen table sipping a coffee and walking you through the cleaning process certainly helped alay my initial fears

Taking a pecpad anywhere near that sensor doesn't give me a good feeling, I think a good stiff scotch might have helped

Thanks for the heads up on the mirror and the AF system. That sounds like an air-rocket or nothing. The mounting and movement of that mirror does not look like it is supposed to support any other weight appart from its own. So let sleeping dogs lie seems like a good approach.

So I guess then air-rocketing the mirror and focussing screen with the camera facing downwards, then locking up the mirror and repeating the air-rocket process seems like a good start. Then if that is not enough to get the sensor clean taking out the Copperhill kit and having a good stiff scotch (or three) to settle the nerves and get to wet cleaning the sensor.

Does this seem like a logical approach ?

/M.

"Now where did I put that Copperhill ordering form?..."

[DaveB]

Just watch the number of scotches you have - don't start feeding them to the sensor (or using scotch instead of methanol). Or using methanol instead of scotch!

Blowing the focus screen and the mirror is a good start. Having the opening facing down helps encourage the dust to leave the body instead of just moving around. BTW, if the dust you can see through the viewfinder is in focus then it's probably on the focus screen and not the mirror.

Then if there's still stuff there, take a PecPad and fold it in quarters (for example) so you have a firm (not too stiff) point. Put a drop of methanol on the tip, and use that to have a go at the spots. Not with your finger pressing behind it: the faint pressure transferred through the folded cloth should be more than enough. Remember, I'm talking here about the focus screen & mirror, not the sensor.

Then if you can still see the crud through the viewfinder (you did make sure the eyepiece was clean didn't you?) it's in focus, but you can't see it on the underside of the focussing screen, you may have the rarer problem of dust having migrated around to the TOP of the focussing screen (this is one of the reasons you have to be careful even when using a blower: forcing dust around the edge of the screen is nasty). Above the focussing screen are typically the AF indicators and then the pentaprism. On most of the "pro" bodies the focus screen is interchangable (in fact I know it's also changable on most of the EOS bodies even if it's not publicised). But at this point I would not be trying to do it yourself without doing a lot more research. I've never had to do this on any of my DSLRs (and they've been through a lot of nasty conditions).

Dust also hides around in the mirror box, and when the mirror flips up and down can get stirred up. So blowing out the mirror box (again with the hole facing down) is good preventative maintenance. The D70 doesn't have mirror pre-fire or I'd recommend using that to flip the mirror up (leaving the shutter closed) while having a quick blow (being careful that the timer doesn't expire and the mirror flop down on the blower - but the D70 doesn't have this so don't worry).

Obviously cleaning the sensor won't have any effect on what you see through the viewfinder. When it comes to cleaning the sensor, I typically do a first pass just using a blower. Then if there are still spots I'll start on the wet treatment. This helps avoid dragging big bits of muck around the sensor...
I'm sure someone's outlined sensor-cleaning techniques, so I'll stop here. Mirror-cleaning was the topic...

[psionic]

DaveB that's for the clarification and the folded pecpad idea. Will try not to get my ethanol mixed up with the methanol

Will have to wait a while and locate a Giotto Air Rocket (or similar) and have another go at those annoying dust bunnies.

/M.

[Grev]

I'm on the same boat as you guys, my focusing screen is so dirty!!!