Dimness in D700 viewfinder

[bert_nelson1]

<

p>I was looking at the D700 at the store today and it was very impressive except for one thing

. When

[Matt Laur]

<p>Your post is somewhat un-intact, above, but: you need a working battery in the camera in order to see the viewfinder in its bright, clear form. It's very common for display cameras to be without a battery, or to be run down.</p>

[michaelging]

<p>Many of the kit lenses they sell with cameras are pretty slow lenses. If that is the kind of lens you will be using then what you see, is what you get. I use 2.8 or faster lenses and my viewfinder in very bright and easy to focus. </p>

[david_carroll4]

<p>Can anyone explain why the optical viewfinder is brighter when the camera is powered up, or even when the battery is live? When I take the battery out of my D70s, it's like someone turned the lights out in the viewfinder (which is, I suppose, exactly what happened).</p>

[jim_momary]

<p>As a result of the above I went to my camera shelf and took down my D200 with a 50mm AF lens and also a 35mm F1.4 manual lens.</p>

<p>I notice (with my D200 turned off) when looking thru the viewfinder with EITHER a manual or auto focus lens on and set it to focus on a scene ...</p>

<p>and then I open the battery door and using my finger allow the battery to drop or to be pushed back up ...<br>

Without the battery the viewfinder goes at least 3 stops darker AND blurry! I do mean out of focus, not just dim.<br>

With the battery pushed in it brightens up again and comes back into the same sharp focus?<br>

What the heck kind of beastie is this evil, possessed camera?<br>

Jim</p>

[alan_huett]

<p>Most Nikon DSLRs have an LCD overlay in the finder - this gives you the focus indicators, gridlines etc. So there is an LCD screen you are looking through that can turn opaque (black) where needed to show various things. LCDs work via polarization, letting light through a polarized filter, or blocking it to get a black symbol. When it is unpowered this overlay defaults to a random level of polarization, thus darkening the viewfinder - add power and the liquid crystals all align and "untwist" a bit to a less polarizing state. More or less power to specific areas generates a fully twisted and thus fully "dark" polarized state.<br>

A slow lens will also affect viewfinder brightness down to about f2.8, anything faster than this adds little light due to the way the focus screen is optimised via prismatic laser cutting.</p>

[jim_momary]

<p>Agreed about the overlay, but does the 'relaxation' of the LCD particulate stuff (nematic fluid) cause a bluriness too? Something along the lines of a cataract.</p>

<p>Here's why I ask, 'cuz with the afore mentioned induced no-battery blur, if I substantially rotate the lens focus ring thru about 15 degrees of rotation. focus returns, somewhat. It is never as sharp as with a battery. In all cases it requires turing the ring to a further distance setting.</p>

<p>As an inquisitive tinkerer and p.t. engineer, I just find the mystery a challenge. An odd thing that will occupy my teeny brain for a bit. Any opinions out there?</p>

<p>Jim</p>