Kalart RF for 203 Ektar?

[Bill_1856]

Can the Kalart RF be adjusted to use with a 203 mm Ektar?

[Jim Noel]

On which camera?

[Leigh]

The longest lens listed in my Kalart book is 6 3/8" (162mm), so probably not.

- Leigh

[rdenney]

Yes. I was able to adjust a Kalart that I mounted on a top-rangefinder Speed Graphic for an Ilex Paragon 8-1/2" lens--longer than the Ektar. (Yes, my Speed now has two rangefinders--on for 127mm and one for 8-1/2".) It was right at the limits of one of the adjustments, though, and I might get a slightly more accurate adjustment if I file out the middle-distance adjustment slot just a touch. The near range (10ish feet) and infinity were perfect. You should not have a problem with the 8" Ektar.

But you must be really meticulous when making the adjustments, and take everything in the right order. It took me several tries to get it to work. I discovered that the position of the following arm on the rangefinder pin is critical--I mean critical--to making use of the full range of motion of the rangefinder needed for long lenses. My rangefinder did not have a flat filed on its input shaft, so I was able to reposition that arm as needed, though that was excessively fiddly. If it has a flat, and the flat is not exactly in the right spot, you'll have to "reshape" that arm slightly. The arm will turn on is pressed-in bushing, but doing so makes it loosen up and it becomes unreliable. If you do end up turning the arm on the bushing, you'll need to use a rivet die to reset the riveted connection.

Rick "whose next project for that Kalart is installing a pet-toy laser in the Focus Spot housing" Denney

[rjmeyer314]

I have an Anniversary Speed Graphic that I use with a 8" Dallmeyer Pentac. I could just barely get the rangefinder adjusted for the lens. I felt that I was at the limit of the adjustments. A 203mm lens will probably work. I suspect that the reason they never put rangefinders on the 5x7 Speed Graphic was the problems in adjusting the rangefinder for 210mm lenses.

[Ivan J. Eberle]

The length of the follower arm has some bearing on the issue. My Meridian is at it's limit with a 210mm plasmat but works albeit about a 6' minimum RF focus (that it works at all is perhaps due to a slightly longer lever than is mounted on other Kalart equipped cameras? Not sure but Meridians do have just a shade larger body than Crowns and Speeds.)

[Kevin Crisp]

The factory Kalart manual lists starting settings for various focal length lenses. The longest one listed is 165mm on a 4x5 camera, which implies either than it won't handle something in the 200's or else they figured nobody would be doing it. I suspect there is an appropriate bed scale you could use for a longer lens if the rangefinder can't handle it.

I think if you tried the longest suggested initial setting of 165mm you might find that you could get the rangefinder accurate at least at infinity and some shorter distance, even if it won't be on for the usual reference points. You'd have to try that to see if it would work.

[rdenney]

The factory Kalart manual lists starting settings for various focal length lenses. The longest one listed is 165mm on a 4x5 camera, which implies either than it won't handle something in the 200's or else they figured nobody would be doing it. I suspect there is an appropriate bed scale you could use for a longer lens if the rangefinder can't handle it.

They did that so people could reset the rangefinder for the lenses they could buy for a press camera. If you calibrate based comparing the ground glass to where the rangefinder converges, you have many more choices than what is listed for specific lenses in their literature.

Rick "not guessing" Denney

[Kevin Crisp]

Yeah, I understand that and I've done it many times. Those numbers are expressly starting points, to be sure, as I stated before. But the adjustment manual does not state the range of focal lengths that the rangefinder can handle, and it doesn't give you a starting point for anything longer than 165mm. I think this implies, as I said, that it either won't work or they didn't think anybody would be trying that. I think it was a relatively rare thing back then that somebody using a press camera as a press camera would be using a 8 inch lens on it. The unmolested 4X5s seem to come with the 127 Ektar or the 135 Schneider most of the time. But there are certainly some out there with the longer Ektars -- 152 and 203.

Unless you have actually been able to calibrate it for a 200+ mm lens, then I think this time you are Rick "sort of guessing" Denney. If you've done it successfully...then the answer is: you can. I thought about giving it a try, but since I finally got mine rock solid at all distances for a 135mm lens, the PITA factor is pretty high. Adjusting one of these is definitely the kind of thing you really want to leave alone when you get it right.

I suspect if this question is posted on the Graphlex.org site somebody can nail the answer.

[Leigh]

But the adjustment manual does not state the range of focal lengths that the rangefinder can handle...
Because that question cannot be answered.

It depends on the Flange Focal Length of the individual lens, which is not the same as its optical focal length.

- Leigh

[Kevin Crisp]

Leigh --

I'm trying to follow your argument. The manual does make suggestions for 165mm lenses because everything in that focal length would have identical flange focal lengths? Same with 135 mm, etc.?

Hopefully someone who knows if a 200mm+ lens will work will chime in.

[Dan Fromm]

What does the flange-focal distance have to do with the RF?

I ask because I just looked at a Pacemaker Graphic with a Kalart. I remembered correctly, the RF is coupled to the right bed rail by a spring-loaded lever that bears on a peg on the right side of the inner bed rail. The peg is actually a slightly eccentric cam, is used for fine adjustment of the RF's infinity setting.

Thing is, all this is independent of the front standard's position on the rail. Whether the RF can be adjusted to coincide at distances closer than infinity when the lens is in focus and the lever is in contact with the peg is an interesting and open question. But and however, as long as the lens focuses to infinity while on the rails and the bed stops are properly positioned, the Kalart can be set to indicate when the lens is focused on infinity.

See http://www.graflex.org/speed-graphic/kalart-adjustment.html

[Ivan J. Eberle]

It depends on a number of factors. Rick Denny and I have both gottn 210mm's to work with side mount Kalarts; long thread here from last summer.

[rdenney]

Unless you have actually been able to calibrate it for a 200+ mm lens, then I think this time you are Rick "sort of guessing" Denney.

Please read the entire thread. I stated in Post No. 4 that I successfully calibrated a Kalart on a Speed Graphic for an Ilex Paragon 8-1/2" f/4.5. I don't know about your calculator, but my calculator says that 8-1/2" is longer than 203mm. I didn't say it was easy, but I did it.

And I was not the only person in this thread to have reported success in calibrating a Kalart for 200mm-class lenses.

Rick "really and truly!" Denney

[Leonard Robertson]

Ivan - This thread? It sure seems to answer the OP's question.

http://www.largeformatphotography.info/forum/showthread.php?t=80545

Len

[rdenney]

Ivan - This thread? It sure seems to answer the OP's question.

http://www.largeformatphotography.info/forum/showthread.php?t=80545

Len

Yes, but you have to read all the way to the end, at least to Post 22 (http://www.largeformatphotography.info/forum/showpost.php?p=778207&postcount=22), where I reported a fresh attempt with a different Kalart and was successful.

Rick "who summarized that thread in Post 4 of this one" Denney

[Bill_1856]

Thanks, felows.
It's such a PITA to calibrate the things, that I wanted to know if it was possible before attempting it.
I have the correct cam for my TRF Crown, but want to use the lens on a Busch Pressman.

[rdenney]

...but want to use the lens on a Busch Pressman.

Note that everything is so close to the edge at this focal length that anything could get in the way. If the Pressman has even a slightly shorter actuator arm, it might not work--a given change in lens position will use up more of the rangefinder's range of travel. But it is certainly worth a try. Just don't give up easily, or you'll end up writing a thread like I did last summer.

Rick "oh, and six feet is about the closest it will focus" Denney

[Leigh]

What does the flange-focal distance have to do with the RF?
Hi Dan (and also answering Kevin),

The FFL determines whether or not the Kalart adjustment has sufficient range to accommodate the infinity focus position.

For example, I have several 210mm lenses in my database (closest I have to 203mm).

The FFLs for these range from 177.2mm (Apo-Symmar MC) to 222.8mm (Super-Symmar XL Asph).

That range is certainly of significance on a small camera such as the Graphics.
The Kalart might work with some but not with others.

Of course this only addresses potential problems at infinity. Close focus is a different but related question.


- Leigh

[Leigh]

...as long as the lens focuses to infinity while on the rails and the bed stops are properly positioned, the Kalart can be set to indicate when the lens is focused on infinity.
If the lens focuses properly at infinity and the bed stops are set correctly...

the Kalart is completely unnecessary. :D

Its purpose is to track focusing at shorter subject distances.

- Leigh

[Leigh]

The manual does make suggestions for 165mm lenses because everything in that focal length would have identical flange focal lengths?
Hi Kevin,

No, the manual makes suggestions for a specific 165mm lens, f/4.5, presumably from a family of lenses listed with that same aperture.

See my post #19 above for further info.

- Leigh

[rdenney]

Hi Dan (and also answering Kevin),

The FFL determines whether or not the Kalart adjustment has sufficient range to accommodate the infinity focus position.

I'm with Dan in that I don't get this.

The flange focal distance is not the focal length. It's the position of the flange with respect to the glass when focused at infinity.

When setting the Kalart, you adjust the focus track to be right at the very end of the Kalart's movement. Fine adjustment is done with the cammed follower that is mounted to the focus track, not to the front standard. Where the lens is "here" or "there" on the focus track so that it is focused at infinity doesn't matter to the rangefinder.

The only thing that affects the rangefinder is the exact focal length, which may indeed vary from the nominal focal length, because that affects the amount of travel needed to move from infinity to some closer point. If one 210 is really 208, and another one is really 212, then the adjustment will not be correct for at least one of them. But that is unrelated to the flange distance. The top-rangefinder Graphics and the Super Graphic had different cams for the same nominal focal length for specific lenses that varied from that focal length sufficiently, but that wasn't because they had a different flange distance.

Generally, the cam follower for the Kalart's actuator arm is set to read "infinity" when the focus track is just out from all-the-way-retracted. That is true for all lenses that will focus to infinity without falling off the track or without occupying the hinge area--all lenses in a photographer's collection for use on that camera. Then, the infinity stops are set to position the lens correctly to focus at infinity.

As an example, focusing from infinity down to 10 feet will require the same amount of lens travel for a telephoto design as for a symmetrical design or even retrofocus design, all of which have markedly different flange distances.

Rick "the rangefinder monitors focus track motion, not lens position" Denney

[Kevin Crisp]

I got a lesson in using the Crown Graphic from a photographer friend who used one daily. He won a Pulitzer (albeit with a Nikon F) so I listened to him...

He said (as per Leigh) the proper way to have infinity set was to have the track fully retracted, and the lens stop set so that when you open the front and pull the front standard out to the stops, you're ready to go at infinity. Lots of these cameras at this age are no longer set up this way. Made sense to me. With a wide angle, you can set the inner stops to accomplish the same thing, then use the bed scale for focus on closer objects.

[rdenney]

...the proper way to have infinity set was to have the track fully retracted, and the lens stop set so that when you open the front and pull the front standard out to the stops, you're ready to go at infinity. Lots of these cameras at this age are no longer set up this way. Made sense to me. With a wide angle, you can set the inner stops to accomplish the same thing, then use the bed scale for focus on closer objects.

Note that the focus track will roll out a bit when you fold down the bed. The rule of thumb is about a tenth of an inch. That gives the ability to rock back and forth across infinity focus if you are using the ground glass. The correct method is to set the stops so that the lens is focused at infinity when the focus track is in the position it assumes when the bed is folded down, which is not fully retracted.

This is about the spot where the Kalart's travel runs out, with the cam follower centered on its range of adjustment, assuming the rangefinder arm is not distorted.

Rick "holding one in his hand right now" Denney

[Bill_1856]

If the lens focuses properly at infinity and the bed stops are set correctly...

the Kalart is completely unnecessary. :D

Its purpose is to track focusing at shorter subject distances.

- Leigh

I don't understand your point. The purpose of the RF is to focus accurately at closer distances when I can't use the GG or don't want to, such as when it's hand-held.

[akfreak]

I have a Paragon 8-1/2" on mine and it is at the end of the adjustment. Maybe a custom linkage could be made

[Kevin Crisp]

I thought the purpose of the RF was to focus accurately at all distances. But if you set it up as suggested, and you want infinity for whatever lens you have the RF calibrated for, you don't need to use it since it will be on the money when opened. We are probably saying the same thing.

[Jim Jones]

I got a lesson in using the Crown Graphic from a photographer friend who used one daily. He won a Pulitzer (albeit with a Nikon F) so I listened to him...

He said (as per Leigh) the proper way to have infinity set was to have the track fully retracted, and the lens stop set so that when you open the front and pull the front standard out to the stops, you're ready to go at infinity. Lots of these cameras at this age are no longer set up this way. Made sense to me. With a wide angle, you can set the inner stops to accomplish the same thing, then use the bed scale for focus on closer objects.

For a journalist this seems best. It's fast and requires no conscious focusing for many subjects. For a pictorialist, being able to rock the focus back and forth for distant subjects may be better. Speed Graphics are ideal for such customization.