Reflex mirror issue on Eos 1 series camera

[jimmy_peterson1]

<p>Hey guys, I'm new here on photo.net making my first foray into 35mm film after using digital almost exclusively since taking up photography. I just purchased a used EOS 1n film body on eBay for a great price and it seems to work perfectly, but I noticed something strange with the reflex mirror: It appears to have a slight greenish tint to it, almost like a very fine, uniform green haze covering the entire extent of the mirror. I am sort of disinclined to attempt to "clean" it with lens paper, as I fear damaging the mechanism. It doesn't look like a typical "dirty mirror, it doesn't even appear dusty, just this very light, uniform green haze, almost like a greenish patina but not thick at all, and not appearing as if it occured as aresult of someone wiping it with something, since there are no smears. I'm assuming it shouldn't look that way, but I'm not even sure to tell you the truth?!<br>

It this something I need to deal with before attempting to use this body with my existing collection of canon lenses? Will this somehow screw up my metering or focusing in a way that's somehow difficult to detect? Or should I just ignore it and use the camera?<br>

Any answers from experience users of this body would be really appreciated. The camera tech places around here won't even talk to you unless you practically agree in advance to hand over your camera to them for a CLA.</p>

[bobatkins]

<p>The reflex mirror on most modern SLRs and DSLRs is partly reflecting, partly transmitting. It's not a 100% reflector and it doesn't look like a first surface mirror.</p>

[jimmy_peterson1]

<p>Does this mean that, basically, the mirror is actually in the original factory condition and <em>should</em> have a sort of foggy greenish tint to it? Is that the gist of what you are trying to convey? Sorry, just confused by your response. I know little about mirrors, first surface or otherwise.</p>

[h_s1]

<p>Jimmy,</p>

<p>This made me look at my 1n's mirror. I have a few bodies of EOS SLR cameras and have actually never really noticed the tint. At most, if I shine a light into the mirror, I can make out that it is not 100% reflecting (since it transmits part of the light to AF sensors just behind it I suppose), but if I were to look at something through that mirror by tilting the camera as an appropriate angle (through the lens mount with the lens off), the color of those objects appears to be correct, no tint there.</p>

<p>On a related note, I am not sure the mirror is supposed to have a tint at all. Do you see the scene in a greenish tint while viewing through the viewfinder?</p>

<p>Congrats on your 1n purchage, though. It is one beast of a camera!</p>

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[bobatkins]

<p>I don't know if any of the mirrors have a tint, but I do know they often look as though they have patches of slightly different reflectivity (can look like dust). Some people think this is dirt and attempt to "clean" them, often resulting in a new mirror being required!</p>

<p>Since the mirror is not in the optical path when the image is being recorded, there's really no need to "clean" it even if it is dirty. Enough dirt could, I guess, result in slight metering errors of maybe even a loss of some AF sensitivity, but you'd need a lot of crud on it to make any appreciable difference in those functions.</p>

[JDMvW]

<p>Whatever, Never use lens tissue on a mirror or you will need a new mirror. Many of them are first surface and very fragile. Use blower.</p>

[jimmy_peterson1]

<p>HS, I don't see a tint when looking directly through the lens mount or when shining a flashlight straight into the mirror. When, however, I hold the camera downwards slightly so that only about half the mirror is visible and shine a flashlight over it from above I am able to see a distinct spotty looking haze covering the surface of the mirror. <br>

I guess I just have no luck buying used equipment. :-(</p>

[h_s1]

<p>Jimmy, if there is really some sort of stuff on the mirror, and it is not easily noticeable, don't worry about it. It won't affect your photos (I don't think it will affect your exposure either, since it is not obvious).</p>

<p>I bought an FTb recently for cheap whose light seals and mirror damper foam were rotting away. I found that when I received it of course. After some searching and help here and other places online, the camera is fixed more less except I do not have the heart, yet, to open it up further and cleaning its shutter. That will have to wait for another day. Meanwhile, it works on slower speeds (less than 1/500) more or less okay.</p>

<p>However, in the process of restoration of that camera, I had to clean the outer edge of the mirror where it had accumulated the rotten foam material while hitting foam in every shutter release. I did that using naphtha and an ear bud. I doused the ear bud in naphtha, spotted the dirty mirror surface with it (only the dirty outer edge, mind you), let it stay for several seconds and gently wiped it with the ear bud. It took around 4 iteration of this procedure to clean that material off the mirror completely. This was followed by very gentle wiping with the ear bud covered with lint free lens cleaner paper (again, only on the affected part of the mirror). And just for the heck of it, I tried pressing the ear bud with some force until I was able to get a visible tiny scratch on an edge (thought it was a good time experiment regarding the fragility of reflex mirrors, I dare not do it on my EOS 5, 50e or 1n). So, all in all, it is not trivial to scratch the mirror (at least in FTb's case) and I ended up with a clean shiny like-new mirror and got great experience in camera restoration. But the newer ones may have more delicate mirrors.</p>

<p>If you want to take a risk (and if that 'substance' is really causing you problem, if not, leave it alone), you can wrap a lint free lens cleaner on a tip of an ear bud, wet it with naphtha and try cleaning one corner of the outer edge of the mirror. The 1.5mm or so of the outer edge, the one near the lens, does not really contribute much to the image, and you can see if the corner is any different form the rest of the mirror after you do the experiment.</p>

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