I was very surprised to find that *nothing* in the viewfinder is ever in focus in the D800 unless a battery is inserted. What causes that? And are there any other SLR cameras that have this "feature"?
Page 33 of the D800 manual says: "When the battery is totally exhausted or no battery is inserted, the display in the viewfinder will dim. This is normal and does not indicate a malfunction. The viewfinder display will return to normal when a fully-charged battery is inserted."
But I couldn't find any reference to lack of focus ability. I find it interesting that they would remove the ability to use the viewfinder and manual focus without the full Li-Ion battery, but personally I don't mind it at all. (In fact, I'd prefer a completely mirrorless model with an EVF and Nikon-One-style PD autofocus.)
This is normal and the same with every DSLR. There is an LCD screen between the focus screen and the prism. That LCD needs power to work, without power it will dim and diffuse the light going thru. So you can focus the image and it will be sharp on the focus screen in the mirror chamber, but you won't be able to see that sharp image since the dim LCD is in the path to the prism/viewfinder.
>This is normal and the same with every DSLR. There is an LCD >screen between the focus screen and the prism. That LCD needs >power to work, without power it will dim and diffuse the light >going thru. So you can focus the image and it will be sharp on >the focus screen in the mirror chamber, but you won't be able >to see that sharp image since the dim LCD is in the path to >the prism/viewfinder.
Ah, thank you for the explanation. That makes sense. By the way, you accidentally wrote "every DSLR", but this issue actually only affects cameras that have an LCD screen in the optical path of the OVF. My Canon 5D2, 5D, and 20D did not have one and so they work normally even without a battery.
>>My Canon 5D2, 5D, and 20D did not have one and so >>they work normally even without a battery. > >Absolutely not. > >Len
Are you saying that I'm incorrect? Because I'm sitting here right now with a 5D2, looking through the optical viewfinder. The sharpness of focus and brightness don't change one bit when I take out the Li-ion battery.
>You say the camera works normally. It doesn't. You might be >able to focus the lens but you can't take a photo.
Sorry, my mistake. I assumed that it would be obvious to anyone that I was referring to the fact that the optical viewfinder can function without a battery, since that was clearly the context of the discussion. I failed to anticipate that anyone could possibly think that what I meant was that the camera can do *everything*, including take photos, without a battery.
Thank goodness that you came along to point out that Canon DSLR cameras cannot, in fact, take pictures without a battery. I can't imagine how many others I might have unintentionally misled into thinking such a feat was possible if it weren't for you. I shall look forward to many more valuable and non-intuitive contributions from you in the future.
Auto focus and the focus indicator circuits all require power to operate as does the SWF motor or the camera body focus motor for auto focus. You could manually focus but the shutter will not work since that also is electronic and the shutter button is just a couple of electronic switches that control the shutter and sensor electronics.