Swapping Lens cells

[croppitt]

Hello all. Got a tricky one that would be keen to hear peoples thoughts.

So, I have a Schneider Apo-Symmar-L 150mm f/5.6 on a linhof comfort board.
I have just bought a Rodenstock APO Sironar S 150mm f 5.6.

Would you
A. just swap lens cells
B. Send to Linhof to get them to do the swap. They suggest I should do that to be sure the lens is set up correctly.

Anything I should be aware of?

*Note: The copal shutter in the original Schneider Apo-Symmar-L 150mm f/5.6 is the newer version ( has click stops) so ideally I like to keep that shutter.

Thoughts?

[Dan Fromm]

Shutters are pretty standard, and I both lenses fit a #0. Just unscrew both lenses cells and put the Sironar cells in the shutter on the Linhof board. If there are shims between the Sironar cells and their shutter, transfer them with the cells. If there are shims betwee the Symmar cells and their shutter, remove and keep with the cells.

[Conrad . Marvin]

The spacing Should be the same on like number shutters, but take out the lens that you don’t want to use and put it aside. Measure the total length of the lens that you Do want to use. Unscrew the cells and put them into the shutter that you want to use and measure the total length. If it measures the same then you are good to go. If there were any spacer rings they should be used in the same place on the “new” shutter. Since you are using the same focal length lens with the same maximum f-stop, the scale should also work.

[Mark Sawyer]

If you're really worried, you can compare whether the two front cells have the same focal length, as a change in magnification would change the entrance pupil size and shift the aperture scale slightly. But I wouldn't expect much difference, let alone enough to matter.

[croppitt]

Thanks to everyone that was a great help. All good ideas to check - brilliant forum




If you're really worried, you can compare whether the two front cells have the same focal length, as a change in magnification would change the entrance pupil size and shift the aperture scale slightly. But I wouldn't expect much difference, let alone enough to matter.

[Dan Fromm]

If you're really worried, you can compare whether the two front cells have the same focal length, as a change in magnification would change the entrance pupil size and shift the aperture scale slightly. But I wouldn't expect much difference, let alone enough to matter.

Why on earth would the OP want to swap a Sironar's front cell with a Symmar's front cell?

[croppitt]

Dan, I think you've missed the gist of the post! you might want to read the original post from the beginning. I was garnering advice about swapping the whole lens onto a comfort board. :o

[Dan Fromm]

Dan, I think you've missed the gist of the post! you might want to read the original post from the beginning. I was garnering advice about swapping the whole lens onto a comfort board. :o

You have a short memory. Please see post #2 above. I was replying to post #4 above.

[croppitt]

You have a short memory. Please see post #2 above. I was replying to post #4 above.

Hi Dan, Sorry, I just don't understand. Could you explain. No idea what bit you think is the wrong approach. Any help or advice is greatly appreciated as I am no expert.:confused:

[William Whitaker]

What is a "Linhof comfort board"? Never heard that term...

[croppitt]

What is a "Linhof comfort board"? Never heard that term...

https://www.linhofstudio.com/products/Linhof-Lensboards/Linhof_Comfort_Recessed_Lensboard_with_QRS

[William Whitaker]

https://www.linhofstudio.com/products/Linhof-Lensboards/Linhof_Comfort_Recessed_Lensboard_with_QRS

Seems like £265 = DIS-comfort. Just sayin'...

[Dan Fromm]

Hi Dan, Sorry, I just don't understand. Could you explain. No idea what bit you think is the wrong approach. Any help or advice is greatly appreciated as I am no expert.:confused:

I answered your question directly and correctly in post #2. I read post #4 as talking about swapping front cells, remarked on that in post #6. Mark might have been suggesting that you check the front cells' pupillary magnifications, which have nothing to do with focal length, to find out whether aperture scale on the shutter on the recessed Linhof board will be right for the lens you're swapping in.

[Mark Sawyer]

Why on earth would the OP want to swap a Sironar's front cell with a Symmar's front cell?

Forgive my lack of clarity, Dan. I wasn't suggesting making a hybrid lens. I was suggesting comparing the two different front cells' focal lengths, to see if they had the same magnifying power. If one is stronger, it would magnify the aperture more, giving a larger entrance pupil. That would throw the aperture scale off. But as I said, in this case, I wouldn't think by much.

[croppitt]

Okay, got it. Thanks, makes sense. Best John

[Mark Sawyer]

...Mark might have been suggesting that you check the front cells' pupillary magnifications, which have nothing to do with focal length, to find out whether aperture scale on the shutter on the recessed Linhof board will be right for the lens you're swapping in.

The focal length of the individual front cells may be different, meaning their individual magnifications also would be different, so yes, they have something to do with each other.

[croppitt]

The focal length of the individual front cells may be different, meaning their individual magnifications also would be different, so yes, they have something to do with each other.

Makes sense, thanks Mark