Nikon F3 contacts beside focusing screen

[ronnies]

Hi,

I'm confused. I have a plain normal Nikon F3 with a DE-2 finder but when I remove the finder there are two contacts on the body (bottom left of the screen if you have the back of the camera towards you ) which seem to be where the F3P has the flash contacts (looking at some photos of the DE-5 it has the pins in the same place). What on earth are these contacts for on a plain F3? I can't find any mention of them anywhere.

Ronnie

 

[Vincent Peri]

The contacts are for the Nikon F3AF (autofocus) camera's DX-1 finder, should you want to use it on your F3. The F3AF camera manual briefly mentions the contacts on page 53. See:

"When handling the F3AF with the DX-1 [the autofocus finder] removed, be careful not to soil or damage the electrical contacts at the bottom of the finder or the matching ones inside the camera body at the top of the mirror box. Also, do not short circuit them."

That's all I could find.

 

[LiamG]

The contacts are for the Nikon F3AF (autofocus) camera's DX-1 finder, should you want to use it on your F3. The F3AF camera manual briefly mentions the contacts on page 53. See:

"When handling the F3AF with the DX-1 [the autofocus finder] removed, be careful not to soil or damage the electrical contacts at the bottom of the finder or the matching ones inside the camera body at the top of the mirror box. Also, do not short circuit them."

That's all I could find.

I've been puzzling about this, and at first when I read your comment I thought "no way! Did they really build compatibility into every regular F3 just for the DX-1 finder of the F3AF?" I was thinking that maybe the contacts would allow the F3P finder to operate on a regular F3- e.g. that they were flash/ready light contacts, but I don't have a F3P finder. I think you're absolutely right, though- according to Wikipedia:

Neither camera could use the DX-1 viewfinder of the F3AF body. Contacts in mirror housing were configured differently than a regular F3 series camera. On an F3P and F3 Limited, they were used for flash synch and ready light purposes. On an F3, F3/T, and F3AF, they were used to communicate the exposure meter display information to the LCD inside the DX-1 viewfinder.

Can anyone confirm that this is the case? Was this just another example of Nikon doing some forward thinking and compatibility planning, or did Nikon plan something else for these contacts?

 

[ronnies]

WellI got a multi meter out today and measured the voltage across the contacts. Nothing until I pressed the shutter release to switch on the metering. I then got about 1.5 Volts across the pins which stayed there for the 16 seconds metering duration then went away again.

Perhaps Nikon put them there in all F3s in case they needed to have power for a future finder?

Ronnie

 

[LiamG]

WellI got a multi meter out today and measured the voltage across the contacts. Nothing until I pressed the shutter release to switch on the metering. I then got about 1.5 Volts across the pins which stayed there for the 16 seconds metering duration then went away again.

Perhaps Nikon put them there in all F3s in case they needed to have power for a future finder?

Ronnie

Interesting! I gotta wonder if they had something else planned besides the DX-1, or they just already knew it was coming and maybe had prototypes when they released the F3.

 

[Mick Fagan]

If my memory is correct, to use the DX-1 viewfinder, you need to remove the ground glass (focusing screen) in the F3 body.

I bought my F3 HP in Germany, it was a 1984 build unit and when at the shop the salesman, later to become a friend who visited us in Australia, was a Nikon aficionado and had pretty much everything Nikon in the cellar part of their store.

The salesman took one of the F3AF units off the shelf and put the viewfinder on my F3HP. Interesting to see the focus aid working, completely unaffordable to me, and frankly, I didn't think too much of autofocus, still don't, but it has a place in photography.

On a later visit, I think 1987, he showed me another trick. He took my Nikkor 50mm f/1.8 lens and put it and the then new TC-16 (TeleConverter) onto the F3AF camera, which turned the manual focus 50mm f/1.8 lens into an autofocus lens, which I think made it into an 80mm focal length, or something around that focal length. Pretty neat party trick I thought.

Information from my German photo shop man at the time, suggests that the F3AF was a toe in the water and also to see the problems and/or limitations with the F3 body. The F4 when released, was given to me for a 6 week trial. My take on it was that it was essentially an F3 body with an inbuilt drive and autofocus capability. There were a couple of other additions, but in a nutshell, that was pretty much it.

Until the day my photo shop friend put the DX-1 finder onto my F3 body, I didn't even know those contacts were there. I had forgotten about them until I read this thread.

Mick.

 

[Christiaan Phleger]

I can confirm that the F3P prism does not trigger flash when used on a standard F3/HP body. It is highly likely that the DX-1 does not function on an F3P body but I've never had the chance to put one on my F3P.
My understanding of the super early AF era is that all the different major camera manufacturers had different technical approaches to the challenges of AF and Nikon got caught out. In the development era of the F3AF the motor in lens was the obvious better solution *except for the fact that the in lens motor technology was not very good; which is why Nikon went in the direction of AF motor in body where it could be bigger and closer to both power and processing. Canon's surprise launch of AF using the in lens Ultrasonic motor really caught Nikon out. Especially with the all important For The Corporate Image was the clear and obvious gap in performance when using the Canon in lens motor telephotos, the equivalent Nikon body/lens combos just could not even compete. Nikon had to wait until some certain patents expired until they could bring to market their own version of the Ultrasonic in lens motor ( I'd argue a perhaps superior motor) and specifically the F5 was created to match what the lens motors could do. For me during my era of photography I saw the skilled use of over 300mm lenses go from a handful to hundreds and the impact that made on the (now former) professional photographers.