I just picked up a Nikon D50 kit and have to say I'm in love with it, but I just noticed something really strange that I'm trying to investigate and maybe someone knows the answer.

With the battery out the viewfinder looks dark and hard to see, and grainy, reminiscent of what i've seen on some of the projects here.

But...

When I pop the battery in the viewfinder becomes many times brighter and much much much clearer, so much so that i can't see any grain.

I've poped off my lens and it doesn't seem to vibrate, it takes a second or two to get dull after i take the battery out, so thinking its not changing the aperature in the lens. (Ya, CPU lens so no manual aperature control)

Anyone know what its doing? Could whatever it is be of use for the 35mm adapter scene?

It is a normal thing. My D50 does the same thing. The viewfinder, in addition to seeing thru the lens, shows the focus area etc.
[Edit: I now realize I'm in the alternative imaging area...sorry about not adding anything to your thread...]

No problem, hoping someone would know why and then maybe adapt this to a 35mm DOF device because like i said, the grain, it seems to dissappear. The GG (or whatever) doesn't seem to move. Is it vibrating I wonder, could a vibration be inducing an increase of brightnes

And since i just got the D50 i'm not planning on dissasembling it any time soon other that to put on a different lense.

Though I'm beginning to suspect that whats happening is that their is a transpartent LCD in front that when it losses power it goes a little dark but not completely, since the guides dissappear when the power is off I see now.

my guess is that without the battery in the auto iris springs shut and hense the darkness and grain.

Has anyone figured this out. it seems like there is something to this one. could it help 35mm adapters be brighter without ghosting?

There may likely be a small LCD display and a splitter mirror reflecting the lens image as well as passing the LCD image directly. When you power down, the LCD backlight will go out, therefore darkening the whole image.

My assumption is that with battery off the aperture is closed and when powered up the lens aperture will open. Watch into the lens when you power up the thing and if you see the aperture opening during the power up it`s just a normal thing. Many lenses are designed that way that they stay closed instead of open when not on camera or when camera is turned off. If that`s the case it can`t add anything to adapter design. Also all the Nikon Crop lenses have no physical control over the aperture so you can not use those on DOF adapter.

Cheers,
T

i just checked it out, and it still happens even with no lens on. the darkening appears to happen somewhere between the ground glass and the diopter. it looks to me that the marks normally on the ground glass are actually from an black and white lcd which blocks light when in a voltage-off state. not particularly useful for 35mm adapters. this is just an educated guess though.