DP-1 Finder for Nikon F-2

Hello everybody,

first at all, congratulations for this forum.

I've a F2 with DP-1, with three lenses (50 mm, 28 mm and 135 mm).

The problem is the measurement of DP-1. If I have a right read with 50 mm, there are a 2 or 3 stops of difference with the 135 mm. Same light, same conditions.

I've adjusted the DP-1 with trim screws and my Sekonic, changet batteries, but it remain the same.

Please, do you have any idea about the reason?

Thank you very much

Not to state the obvious, but as a first question-

Are you properly indexing the lenses when first installed? Before installing, push the pin in the center up until you hear a "clunk" and the little window reads 5.6. After installing a lens, I suggest turning to minimum aperture to "grab" the pin, then turning to maximum aperture to index this. You should hear a ratcheting click as you move toward maximum, and once there the little window should read the maximum aperture of the lens.

Hi, Ben,

Yes. Always, after mount lens, I move right-left the f ring to index lens.

Thank you!!

What's the aperture of your 135mm lens? F/3.5 or smaller maybe?

F2 meters measure off the screen, so once a split-image distraction rangefinder blacks out, all bets are off.

I've adjusted the DP-1 with trim screws and my Sekonic

Bad move!

The main cause of error or erratic reading is the resistor ring, which gets dirty. The trimmers shouldn't need to be touched after factory adjustment.

What screen are you using? Some of the rare screens gave different readings for different focal length lenses. BUT- not this dramatic of a difference.

The readings could be explained of the Indexing Mechanism is not working properly, is somehow jammed.

Does the meter give the correct exposure for the 50mm lens? What is the max aperture of the 50? The DP-1 could handle an F1.2 lens. How far did you have to adjust the trim screws?

What screen are you using? Some of the rare screens gave different readings for different focal length lenses. BUT- not this dramatic of a difference.

I can't find the full chart, but IIRC the most EC some called for was about +/-1 stop.

In general, though, unless you have a good reason to do otherwise, it's probably best to stick with the A, E, J, K, L, and P screens. I have piles of F/F2 screens, and rarely do I use anything other than an A, K, or E(I never warmed up to L and P screens, even though I know some people love them).

What's the aperture of your 135mm lens? F/3.5 or smaller maybe?

F2 meters measure off the screen, so once a split-image distraction rangefinder blacks out, all bets are off.

 

My 135 is F/3.5

 

Bad move!

The main cause of error or erratic reading is the resistor ring, which gets dirty. The trimmers shouldn't need to be touched after factory adjustment.

:-(

I followed the Glen Walpert tutorial about DP-1 adjust.

The damaged is done

thanks anyway

What screen are you using? Some of the rare screens gave different readings for different focal length lenses. BUT- not this dramatic of a difference.

 

I think it's a Type J

 

The readings could be explained of the Indexing Mechanism is not working properly, is somehow jammed.

 

Does the meter give the correct exposure for the 50mm lens? What is the max aperture of the 50? The DP-1 could handle an F1.2 lens. How far did you have to adjust the trim screws?

Yes. The metering is right for 50 mm. It's a F/1.4

Thank you

The J screen does not require any compensation.

As you are using an F1.4 lens- that is close to the DP-1 max aperture index. You adjusted it for the lens- for the 135 to be off so far, I would first check the indexing mechanism that it is releasing properly with the lens dismounted and then comes up to the correct mark.

I can't think of anything else.

There is a way to use the meter- use it like an old T or Tn finder and manually index the meter using the ASA dial. Make some marks for the max aperture of the lens, and adjust by changing the ASA.

Hello,

really , it's very strange.

I afraid that 135 mm is the problem.

For instance, I mount 50 mm, meter with DP-1 and Sekonic. Same speed and f DP-1 and Sekonic (for example: 250 f/5.6)

I change to 28 mmm. Same speed and f

I mount 135 mm, and I need 2 or 3 more stops

I've checked 135 mm, and I can't see any problem. It indexes when mounting.

Thank you

Hello,

I think that problem is fixed.

I Removed the focus screen from the camera to know the right model. It's a G2 screen. This table - pag 24 (https://www.cameramanuals.org/nikon_pdf/nikon_f2_finder_dp-1.pdf) says that with G" screen, 50 mm f/1.4 needs a +1/2 correction, and 135 mm f/3.5 needs a -1 correction.

So I adjusted trim screw of my DP-1 using 35 mm according my sekonic meter.

Now, when I shot 135 mm (-1 stops adjusting) it's fine.

Thank you very much everybody!!