t3i/600d viewfinder problem

[taitypot600d]

hi,

i have a 600d (im english) and i have an issue with the viewfinder, i have just noticed this issue the last couple days - 

basically, when looking through the viewfinder, everything is fine, dioptics, text, AF points, except one thing, when looking at a light out of focus (trying to get a good bokeh or something), whether it be from close up or a good distance, there appears to be what i can only describe as a 'honeycomb' effect in the light, sort of as if the light is broken up into little individual lights. its hard to explain as ive never heard of or seen this in any posts. 

was just wondering if anyone could shed a little light on this?

cheers

andy

[TCampbell]

Not being able to look through your camera, I'm trying to imagine what you might be seeing.

There is a small focusing wheel for the viewfinder itself.  This allows you to correct the viewfinder for your eyes (a person who normally uses eyeglasses can adjust it so that it corrects enough that they don't need to wear glasses when using the camera.  It can adjust for near-sighted or far-sighted vision, but cannot correct for astigmatism.)

To focus it, I find it works well to point at a "bright" but yet low-contrast target (such as a white lampshade) and then deliberately de-focus the lens.  You can now adjust the focus of the viewfinder (using the tiny wheel adjacent to the viewfinder) until you get the focus points tack-sharp.  Having a bright low/no-contrast image in the viewfinder makes it much easier to see the fine detail on the focus of the viewfinder. 

When they are tack-sharp, you'll notice these out-of-focus areas have a "texture" to them -- sort of like a pebble or matte finish.  This is normal and is caused by a slight frosted coating applied to the focusing screen.  

Recall that old viewfinder cameras (the type that took sheet film loaded into the film hanger) simply had frosted glass on the back -- the photographer put the black drape over their head so they could inspect and focus the image on the frosted glass.

This is basically what your camera is doing... it is projecting an image onto that frosted glass and the glass -- which has a texture.  Meanwhile, the fiewfinder is basically a magnifying loupe which allows your eye to inspect the image projected onto that frosted "glass".

On some cameras the viewfinder screen can be replaced with different types -- some are especially good for helping you detect out of focus areas when manually focusing the camera.

So I *suspect* that what you are seeing is the effects of an out-of-focus light on the frosted focusing screen surface.  

If so, this is actually normal and is not a defect.  BTW, the focusing screen isn't used when the camera takes the photo... the mirror swings up and clear allowing the light to pass directly back to the sensor.  

[Skirball]

I'm assuming you don't see this same honeycombing when viewing on the LCD or on a computer afterwards?  And you're not referring to the honeycomb/non circular shape that bright points of light take on when out of focus?