Spots Through The Viewfinder

[erainn]

On looking recently though the viewfinder of my Canon EOS 450d I noticed two small dark flecks, smaller in size than the focus points, but nevertheless noticeable. I cleaned my lens and on removing it from the camera body it was apparent the issue lies within the camera somewhere. I had also cleaned the viewfinder glass. I'm wondering what this may be and if there's anything that can be done to remove whatever it is. Any advice or experience of similar issues would be good to hear. Thanks, Erainn

[Polar01]

Just on a off chance did you clean the mirror?

Cheers: Allan

[erainn]

Hi Allan, thanks for your comment, Nope I have not touched the mirror for fear of causing some 'damage'. Erainn

[Manfred M]

These are likely spots on the focus screen of the camera. I have these too. If they are on the outside surface, you could likely remove them with a soft, clean brush. If they are on the inside of the screen, that can only be cleaned by disassembling the camera.

The good news is that this will have no effect on the pictures you take,

[erainn]

Hi, Forgive the noob flavour of the question, but how to access the outside of the focus screen?

[Polar01]

To remove the dust bunnies from the mirror, remove lens, use a blower and blow air onto the screen, or use a lens brush and brush away the dust. You will not hurt the mirror if you use a soft lens brush.

Cheers: Allan

[erainn]

Hi Allan, Thanks for the suggestion, will give it a go. Erainn

[Manfred M]

Hi, Forgive the noob flavour of the question, but how to access the outside of the focus screen?

The focus screen is in the roof of the mirror box, above the mirror. Remove the lens and lay the camera on its back; you will see the focus screen.

[erainn]

GD, Thanks will take a peek at that. Erainn

[erainn]

Thanks for all the really helpful advice, having cleaned the mirror & focus screen the offending spots are now nicely cleaned up.

[Shadowman]

Hi Erainn,

Just curious if you notice the specks on printed image or on your monitor after uploading? You can usually edit the defect, but if you are like me it can be quite annoying especially if the speck is positioned in an important area of the composition.

[erainn]

Hi, will look into that, hopefully they will not be present

[Polar01]

Erainn if the spots are gone after cleaning both the mirror and focus screen, they would never appear on an image.

Cheers: Allan

[Dave Humphries]

Hi Erainn,

When attempting to clean them out, I suggest you hold the camera above your head, with the lens opening pointing downwards, perhaps ideally with the camera at a 45 degree angle, with edge of mirror directed to floor. This will allow the dust to fall and/or be blown out, not fall further in to the camera's innards. You could even try some gentle taps to see if they can be persuaded to fall out, but keep a good hold, don't risk dropping it. Then try blowing (rocket blower) or dusting.

This applies whether the dust is on mirror or focus screen.

Do ensure the camera is switched off - you don't want to risk accidentally triggering the shutter while you have something like a blower or brush inside the camera, particularly between the mirror and focus screen.

You may want to try playing torch light through the viewfinder to illuminate the focus screen and see if you can see the specks by naked eye looking in to the lens throat, this will be easiest done with camera upside down on a table top.

Needless to say (and apologies for possibly stating the blooming obvious), you should do all this in a clean (dust free) environment, not the workshop having just sawn some timber

Hope that helps, Dave

[erainn]

Dave, thank you very much, shall make a careful note of those suggestions.

[Timar]

Didn't work for my floaters, unfortunately

[barrydoig]

Erainn, although you solved the problem this time, because it was spots on the mirror or focus screen, it is important also to know how to clean the sensor of your camera. Spots on your images means they are on the sensor, requiring a rather delicate cleaning process. It can be done by your local camera shop but that gets expensive. You can do it yourself but you need a proper cleaning kit for the price of about three visits to your camera shop for a clean. Make sure you get a kit with the loupe to enable you to view the sensor after you remove the lens. To clean the sensor you must switch the camera on and lock the mirror up so it doesn't come down on your cleaning brush and cause damage. There is a Menu in the 450d that will help you do this. Remove the lens, hold the camera down, and follow the instructions for cleaning the sensor using the loupe and the proper blower and brush for the purpose. To lower the mirror just switch the camera off. To clean the mirror, remember that it is silvered on the front, not on the back like your bathroom mirror, so be careful to use proper lens cleaning tissue. This may sound complex but believe me it works and is a necessary evil for us dslr users. Do not use a cheap blower as this will leave hairs in your camera. Likewise never use any aerosol blower as the propellant can enter your camera. Hope this helps
Barry from Down Under

[Timar]

Regarding sensor cleaning - poeple make a lot of fuss about it, but it isn't quite as a delicate process as often made out if it. Believe me, anyone who has ever seen the rough way it is routinely done in camera shops rather wants to do it at home. All it takes is 99% pure isopropanol and/or distilled water, a soft, non-perfumed handkerchief and a plastic clothespin. You cut a piece out of the handkerchief with the same width as the sensor height, pinch it with the clothespin in such a way that it gives a plain surface protuding over both sides of the clothespin, making sure there is no way for the plastic to come in contact with the sensor. Then you soak it with isopropanol or distilled water, squeeze it on another piece of handkerchief to make sure it doesn't ooze the booze and gently strike honrizontally from the one side to the other on the sensor, about ten times. Inspect the sensor under a magnifying glass. If there is any dirt remaining, try again with distilled water (if you have used isopropanol) or vice versa. Cost: 2$ for 1 oz of isopropanol, plus a few cents for a bottle of distilled water, both enough to lasts for many years and several camera bodies to come Also great for lens cleaning btw.

[Manfred M]

Regarding sensor cleaning - poeple make a lot of fuss about it, but it isn't quite as a delicate process as often made out if it. Believe me, anyone who has ever seen the rough way it is routinely done in camera shops rather wants to do it at home. All it takes is 99% pure isopropanol and/or distilled water, a soft, non-perfumed handkerchief and a plastic clothespin. You cut a piece out of the clothespin with the same width as the sensor height, pinch it with the clothespin in such a way that it gives a plain surface, protudes over both sides and there is no way for the plastic to come in contact with the sensor. Then you soak it with isopropanol or distilled water, squeeze it on another piece of handkerchief to make sure it doesn't ooze the booze and gently strike from the right to the left on the sensor, about ten times. Inspect the sensor under a magnifying glass. If there is any dirt remaining, try again with distilled water (if you have used isopropanol) or vice versa. Cost: 2$ for 1 oz of isopropanol, which is enough to lasts for many years and several camera bodies

Agreed that sensor cleaning isn't that hard, but I've also seen messed up results from poor practices and cleaning methods. A poor cleaning can and will result in even worse problems than no cleaning at all. It really depends on ones technical skills and steady hands. I have not had to resort to wet cleaning any of my camera's sensors, not yet at least, although I've done wet cleanings on other peoples cameras.

Regardless, the issue was not a dirty sensor problem.

[wobert]

Also consider the possibility that the mirrored surfaces on the glass in the pentaprism are deteriorating.
So- Spots on reflex mirror? on ground glass screen above reflex mirror? on ground glass screen within the reflex housing? on the mirrored surfaces of the penta-prism?