New Lens Question

DebbieT · Dec 11, 2014

Hi all!

Recently purchase a calumet 4x5 camera with an extra long rail. In my haste to find an affordable lens and get shooting I bought one off ebay. I am now not sure what I purchased. . Normally I am very selective about purchasing gear, but the price made me hastey.

Here is the description:

"For sale is a Caltar II 210mm f5.6 large format lens. Glass is clean. It is mounted in a Copal #1 shutter that is labelled SW-Nikkor 150mm f8. You could make another mark beyond f8 to provide an f5.6 setting. Shutter sounds good and the aperture blades are clean."

My question is... How can this Caltar lens have a Nikkor shutter? Will this cause problems?

Any feedback would be appreciated as Im new to the format.

Deb

Jesper · Dec 11, 2014

It should work but you need to get a correct f scale. If the scale is for a 150mm lens the markings will be wrong for 210mm.
Having a Copal shutter is not a problem. It is perhaps the most common shutter and it is common to find shutter of a different brand than the lens (lenses and shutters are made by different manufacturers).

DebbieT · Dec 11, 2014

Thanks guys! @Jesper @APUGuser19

Back to the hunt for my first lens!

Deb

gone · Dec 11, 2014

Don't bail out too soon. When you get the lens, ck to see if infinity focus is sharp on your camera's ground glass. I suspect that it will be fine. If it is, no worries. You can figure out the f stops in all likelihood too w/ a little research,

Steve Smith · Dec 11, 2014

APUGuser19 said:
You don't know what your f/stops are

But it's easy to work it out:

On simple terms, the f No. is the focal length divided by the aperture diameter.

e.g. with the original 150mm lens, the f11 position would set the aperture blades to 150/11 = 13.6mm diameter.

If you now fit the same shutter with a 210mm lens, the aperture diameter when set to f11 is still 13.6mm so the actual f No. will now be 210/13.6 = f15.4 which is very close to f16.

So with a 240mm lens in this shutter with markings for a 150mm lens, adding one to the indicated f No. will be close enough for negative film.

Steve.

wiltw · Dec 11, 2014

All is not lost! We will start with an explanation...
First of all, large format lenses are mounted onto shutters like the Copal 1 like you have.
Then the diaphragm scale is mounted onto the shutter. In your case, the shutter was set up for a Nikkor 150 f/8, but a different lens was mounted on the same shutter, seemingly 'all messed up'. So let's now help you out.
150mm divided by f/8 = 18.75mm diameter
210mm divided by 18.75mm = f/11 ...so with your lens you really have f/11

Computing the entire sequence of whole f/stops...

150 f/, diam, 210 f/, 210 nominal f/
8, 18.8, 11.2, 11
11, 13.6, 15.4, 16
16, 9.4, 22.4, 22
22, 6.8, 30.8, 32
32, 4.7, 44.8, 45
45, 3.3, 63, 64

DebbieT · Dec 11, 2014

You all are fantastic! Thank you for sharing! @momus @SteveSmith

DebbieT · Dec 11, 2014

Wow! That is amazing! Thank you! @wiltw

First of many detours on my road to learning this format!

But how fun is this? Loving it!

Deb

Sirius Glass · Dec 11, 2014

DebbieT said:
Hi all!

Recently purchase a calumet 4x5 camera with an extra long rail. In my haste to find an affordable lens and get shooting I bought one off ebay. I am now not sure what I purchased. . Normally I am very selective about purchasing gear, but the price made me hastey.

Here is the description:

"For sale is a Caltar II 210mm f5.6 large format lens. Glass is clean. It is mounted in a Copal #1 shutter that is labelled SW-Nikkor 150mm f8. You could make another mark beyond f8 to provide an f5.6 setting. Shutter sounds good and the aperture blades are clean."

My question is... How can this Caltar lens have a Nikkor shutter? Will this cause problems?

Any feedback would be appreciated as Im new to the format.

Deb

I had the same problem. I sent it to S. K. Grimes and he made the correct aperture scale for me. Worth the $75.

E. von Hoegh · Dec 11, 2014

DebbieT said:
Hi all!

Recently purchase a calumet 4x5 camera with an extra long rail. In my haste to find an affordable lens and get shooting I bought one off ebay. I am now not sure what I purchased. . Normally I am very selective about purchasing gear, but the price made me hastey.

Here is the description:

"For sale is a Caltar II 210mm f5.6 large format lens. Glass is clean. It is mounted in a Copal #1 shutter that is labelled SW-Nikkor 150mm f8. You could make another mark beyond f8 to provide an f5.6 setting. Shutter sounds good and the aperture blades are clean."

My question is... How can this Caltar lens have a Nikkor shutter? Will this cause problems?

Any feedback would be appreciated as Im new to the format.

Deb

It's possible that some kind soul with the same lens can scan the aperture scale for you. The Caltar is a rebadged Schneider (IIS) or Rodenstock (IIN), either way it's excellent if properly mounted and spaced.

Jon Shiu · Dec 11, 2014

I would say don't buy it. Save yourself the time and trouble/expense and get a lens in the original shutter, otherwise you can't be sure on the accuracy of the aperture. The 210mm f5.6 lenses are not expensive these days.

Jon

Konical · Dec 11, 2014

Good Evening, Debbie,

I agree with Jon. The Caltar 210 is a fine lens, but it's easy to find one (or a similar Rodenstock, Nikon, Schneider, Fuji, etc.) properly set up in a shutter.

Konical

John Koehrer · Dec 11, 2014

The OP already has bought the lens.

And yet another method of figuring your f stops:
Viewed from the front The maximum f stop of your lens should measure 37.5mm. Each halving of that is one f stop.
37.5=f5.6
18.75=f8
9.37=f11
and so on..........

Jon Shiu · Dec 11, 2014

If the buyer and seller agree to cancel the sale due to a mistake, it is no big deal.

Jon

Sirius Glass · Dec 11, 2014

Sirius Glass said:
I had the same problem. I sent it to S. K. Grimes and he made the correct aperture scale for me. Worth the $75.

I tired measuring and calculating the f/stops. Then making labels. That was not a problem since I am an engineer. All that work was not worth the effort and I sent it off to have a new metal plate made. It was worth the effort and I would do it again if the situation arose.

E. von Hoegh · Dec 12, 2014

John Koehrer said:
The OP already has bought the lens.

And yet another method of figuring your f stops:
Viewed from the front The maximum f stop of your lens should measure 37.5mm. Each halving of that is one f stop.
37.5=f5.6
18.75=f8
9.37=f11
and so on..........

Errrm...

If 210/37.5 = 5.6, then 210/18.75 = 11 and 9.37 is f:22, intervals of two stops due to the fact that area equals pi times the radius squared.

Jim Jones · Dec 13, 2014

John Koehrer said:
The OP already has bought the lens.

And yet another method of figuring your f stops:
Viewed from the front The maximum f stop of your lens should measure 37.5mm. Each halving of that is one f stop.
37.5=f5.6
18.75=f8
9.37=f11
and so on..........

The F/stop is determined by the ratio between focal length and the entrance pupil of the lens. The entrance pupil is the apparent diameter of the diaphragm as seen through the front lens cell, not the physical diameter of the diaphragm. Allow for parallax when making this measurement.

desertrat · Dec 13, 2014

Paraphrased from Photographic Facts and Formulas:

Mount lens and focus a very distant object on the ground glass. Without disturbing the focus, place an opaque card with a pinhole in the center against the inside surface of the ground glass. Removing the camera back is probably the easiest way to do this. Replace the back with card installed and bring the camera into a darkened room and place a strong light source near the center of the of the screen where the pinhole is. Sprinkle a little fine talcum powder on the front surface of the lens. The visible circle of light on the front lens element represents the true aperture of the lens. Measure the diameter of the circle of light and calculate the f number.

You could probably place the card against the rear surface of the ground glass, much easier, and the focus shift would probably introduce a negligible error in your f number calculation. Trying to accurately measure the circle of light on the lens element would probably introduce more error than the focus shift. I don't believe the f number calculations need to be super accurate to make the camera usable. Variations in lighting and exposure would probably swamp out the error in measurement.

John Koehrer · Dec 13, 2014

E. von Hoegh said:
Errrm...

If 210/37.5 = 5.6, then 210/18.75 = 11 and 9.37 is f:22, intervals of two stops due to the fact that area equals pi times the radius squared.

Jim Jones...."The F/stop is determined by the ratio between focal length and the entrance pupil of the lens. The entrance pupil is the apparent diameter of the diaphragm as seen through the front lens cell, not the physical diameter of the diaphragm. Allow for parallax when making this measurement."

Ooops!

What they said.

RalphLambrecht · Dec 13, 2014

momus said:
Don't bail out too soon. When you get the lens, ck to see if infinity focus is sharp on your camera's ground glass. I suspect that it will be fine. If it is, no worries. You can figure out the f stops in all likelihood too w/ a little research,

I 2nd that,plus Caltar doesn't have a bad reputation.If I remember correctly ,it was Calumet's house brand;an economy but decent lens.Being bias to Nikon,I went with all Nikkors aas I did in the darkroom and for 35mm;never was disappointed by Nikon yet

Sirius Glass · Dec 13, 2014

As the OP and the anyone casually walking down the street chewing gum can see making you own basically inaccurate scales is not worth the hassle, just send it off and have a correctly made f/stop scale.

Alan Gales · Dec 13, 2014

RalphLambrecht said:
I 2nd that,plus Caltar doesn't have a bad reputation.If I remember correctly ,it was Calumet's house brand;an economy but decent lens.Being bias to Nikon,I went with all Nikkors aas I did in the darkroom and for 35mm;never was disappointed by Nikon yet

Ralph, from what I heard, you are correct about the Caltars being a Calumet house brand. They were a little cheaper than their name brand counter parts but actually the same lenses. The lens in question is actually a Rodenstock Sironar (APO) N which is a great lens. Caltars can be rebadged Rodenstocks, Schneiders, Topcons or Ilexes.

Ian Grant · Dec 13, 2014

Sirius Glass said:
As the OP and the anyone casually walking down the street chewing gum can see making you own basically inaccurate scales is not worth the hassle, just send it off and have a correctly made f/stop scale.

Totally agree where it's possible I'd try and get the correct scale, they are still available for Copal shutters.

Part of the problem here is the seller has no idea of the ratios between FL and aperture etc and is rather gun-ho about it. Unless it's a ridiculously cheap price or you're confident of what you are doing pass on it.

Ian

Alan Gales · Dec 13, 2014

Ian Grant said:
Totally agree where it's possible I'd try and get the correct scale, they are still available for Copal shutters.

Part of the problem here is the seller has no idea of the ratios between FL and aperture etc and is rather gun-ho about it. Unless it's a ridiculously cheap price or you're confident of what you are doing pass on it.

Ian

I'd pass too. There are plenty of 210mm f/5.6 lenses out there in modern Copal shutters for the cheap. Take your pick from Rodenstock, Schneider, Nikkor, Fujinon or Caltar. They are all sharp and contrasty and have very little difference between them. Let price and condition be your guide as to which to buy.

ic-racer · Dec 13, 2014

Alan Gales said:
I'd pass too. There are plenty of 210mm f/5.6 lenses out there in modern Copal shutters for the cheap.

This, this, this ^^^

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