Agfa Karat IV -- rangefinder adjustment

[KoNickon]

Anyone know how to do this? Mine focuses just short of infinity. I think the top cover looks easy to remove -- take off the rewind knob and three screws. But how to adjust it once the RF mechanism is accessible? There are a couple of lengthy and excellent presentations out there, by Messrs. McFarland and Sherlock, but neither of them deals with adjusting the rangefinder. (They are working with the Karat 36, which has the unusual split image RF, a different mechanism. The Karat IV has the conventional superimposed image, which is probably a good thing for my purposes.) Thanks.

 

[KoNickon]

OK, I screwed my courage to the sticking point and removed the top cover (really, very easy). The horizontal, i.e. infinity adjustment is done via a screw that's clearly visible in a hole toward the back of the top cover of the rangefinder assembly, near the viewfinder. Quite simple.

 

[KoNickon]

And I buttoned things back up without looking underneath the top cover -- but I wouldn't be surprised if removing the spring steel insert in the accessory shoe would reveal a hole in the top cover giving direct access to the adjustment screw. It's in the right location. I tried checking just now but I don't have the right tool to pry it off without marring it.

 

[KoNickon]

I should have followed up on this -- no, there is no access hole under the accessory shoe. But taking off the top cover is indeed quite easy, as mentioned above.

On the other hand, I tweaked the rangefinder adjustment on my Taron 35 (nice little late '50s camera) over the weekend. Remove the accessory shoe (three screws) and there are two holes. Smaller one with larger screw is infinity adjustment; rectangular hole with two small screws is for the vertical, though I couldn't figure out why two screws. Would that all rangefinder adjustments were that accessible.

 

[titrisol]

I dont have experience with the Karat IV, but from a pic found elsehwere it looks very similar to the Isolette III and Solinette-Super RFs

Easy to adjust horizontally, not so easy vertical

 

[KoNickon]

Agree. Don't ask me how to adjust the RF on the Karat 36 -- the one with the offset windows. That's a whole different animal I think.

 

[titrisol]

Agree. Don't ask me how to adjust the RF on the Karat 36 -- the one with the offset windows. That's a whole different animal I think.

That one is extremely easy, just slide the unit L or R until infinity is fine and presto!

 

[KoNickon]

Wow! Fortunately my K36 focuses fine but that's good to know. I take it there are screws holding the assembly in place?

 

[titrisol]

Yes, the ones marked in yellow. The RF is coupled by a lever that moves the RF as the lens unit moves,

The RF assembly has a pin that moves it Left to Right and a spring that return to infinity. If that movement is sluggish you have to clean the rail. I used a qtip with electrical contact cleaner and then lubricated with a little powdered graphite.


and by adjusting the horizontal position of the assembly to the point were it matches the lever then you can adjust the focusing.

 

[titrisol]

PS, I didnt touch the insides of the RF mechanism as it was working fine (albeit sluggish). I only cleaned the glass with a qtip and windex.

 

[KoNickon]

So, loosen those screws with the RF at infinity and slide left/right as needed to bring the images into alignment? And then tighten.

 

[titrisol]

So, loosen those screws with the RF at infinity and slide left/right as needed to bring the images into alignment? And then tighten.

Xaclty, I'dd add a checkpoint at 6ft before closing the top to ensure close focusing is correct