Putting a copal 1 150mm f5.6 lens on a copal 3 shutter via adapters, what to expect?

[MartyNL]

Hi all, so since a Xenotar 150mm f2.8 is way beyond my budget, it got me thinking about putting a standard 150mm f5.6 copal 1 lens into a standard copal 3 f5.6 shutter via adapters for the front and back cells.

So will this set-up make my f5.6 lens a much faster lens?
And what do you think I should expect, image wise?

[Oslolens]

Nope, no more light.
Buy a 150mm f3.5 Xenar in shutter, or a 150mm Heidosmat to front mount, or 58-Copal-to 58mm-filter-adapter to use two +3 close-up lenses to get a 166mm f3.7

Also this will cost you, though.
My bokeh tests: https://www.flickr.com/photos/47052585@N06/albums/72157634939838558



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[Oslolens]

The Copal 3 only has 45mm opening.
My Ilex #5 has 65mm opening, but only changes the f stop from 7.4 to 5.1 on a +3 close-up (333mm) lens. If used on two +3 close-up lenses you end up at f2.55 but might want to use a smaller aperture anyway.
I paid $75 each for my adapter ring for my Ilex #5, but found to my surprise the 14" early Ektar will take 72mm filter straight on.

How big shutter do you have room for?

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[ic-racer]

Hi all, so since a Xenotar 150mm f2.8 is way beyond my budget, it got me thinking about putting a standard 150mm f5.6 copal 1 lens into a standard copal 3 f5.6 shutter via adapters for the front and back cells.

So will this set-up make my f5.6 lens a much faster lens?
And what do you think I should expect, image wise?
If you want to use that method to increase speed, it is much easier to just fit a new aperture scale. Maybe one that goes to f1.4 :)

[MartyNL]

Back to the drawing board, it seems!

[Bernice Loui]

What is the intended goal ?


Bernice



Hi all, so since a Xenotar 150mm f2.8 is way beyond my budget, it got me thinking about putting a standard 150mm f5.6 copal 1 lens into a standard copal 3 f5.6 shutter via adapters for the front and back cells.

So will this set-up make my f5.6 lens a much faster lens?
And what do you think I should expect, image wise?

[MartyNL]

What is the intended goal ?


Bernice

To try and create a Xenotar 150 f2.8 but without the expense!

[Oslolens]

Here is the f3.5 Xenar 165mm, almost there: https://www.ebay.com/itm/265248126088?hash=item3dc2053488:g:-CwAAOSwGO1hBPBj

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[Dan Fromm]

To try and create a Xenotar 150 f2.8 but without the expense!

Fast, inexpensive, good? Which two do you want?

[MartyNL]

Fast, inexpensive, good? Which two do you want?

Fast and inexpensive. Good is relative.

[MartyNL]

Yes, I've seen this lens and a Xenar type D both a lot cheaper than a Xenotar!
The thing is, I have copal 3 shutters and lenses for copal 0 & 1 and I was hoping for a work around. It seems there are no examples?
Perhaps I should just find out the cost of adapters and if viable, give it a try myself. Could be fun!

[Bob Salomon]

Yes, I've seen this lens and a Xenar type D both a lot cheaper than a Xenotar!
The thing is, I have copal 3 shutters and lenses for copal 0 & 1 and I was hoping for a work around. It seems there are no examples?
Perhaps I should just find out the cost of adapters and if viable, give it a try myself. Could be fun!

How would the larger shutter make the glass larger?

[Dan Fromm]

Yes, I've seen this lens and a Xenar type D both a lot cheaper than a Xenotar!
The thing is, I have copal 3 shutters and lenses for copal 0 & 1 and I was hoping for a work around. It seems there are no examples?
Perhaps I should just find out the cost of adapters and if viable, give it a try myself. Could be fun!

Marty, what you're trying to do is impossible. That's why there are no examples.

[Dan Fromm]

How would the larger shutter make the glass larger?

Bob, the OP believes in magic. I know why I don't, for me magic is another way of saying wishful thinking. Why don't you believe in magic?

[MartyNL]

How would the larger shutter make the glass larger?

I realise it's not the same as having big glass. Although you hear of people removing the aperture insides of brass lenses in order to increase the size of the aperture and therefore using a larger portion of the existing glass/image circle.
I'm just very curious what the effect would be and if anyone has tried it before?

[Paul Ewins]

You could buy them new in a Compur Electronic 3, but that didn't change the maximum aperture. f5.6 is the maximum aperture for that design regardless of how it is mounted and a number 1 shutter is simply the smallest (and therefore cheapest) shutter that wouldn't reduce that. The example with brass lenses is more complex because the aperture excludes the outer edges of the image circle that had the worst aberrations. In more modern designs that simply isn't necessary and the shutter gives a straight through path when wide open.

[Bob Salomon]

I realise it's not the same as having big glass. Although you hear of people removing the aperture insides of brass lenses in order to increase the size of the aperture and therefore using a larger portion of the existing glass/image circle.
I'm just very curious what the effect would be and if anyone has tried it before?

It’s the diameter of the useable front element and the focal length. Nothing else. You can’t increases the speed of your lens. Stop wasting your time.

[Sean Mac]

Fast and inexpensive. Good is relative.

https://www.largeformatphotography.info/forum/showthread.php?35097-A-new-line-of-Chinese-pictorial-lenses!

:)

[cowanw]

MartyNL I expect you are referring to the practice of chokeing down something like a Cooke portrait lens to F8 or 11 to make a Rapid view landscape lens. Yes has been done but you do need the choked lens to be able to unchoke it.

[Rod Klukas]

The exit and entrance pupils inside a lens will never allow you to make it faster. They are fixed for the lens.

Also the groups are set in a collimated, setup, at the factory. Just changing shutters may lose you some of the original factory setup's sharpness. Many times lenses had carbon shims inserted behind the front group, to more perfectly set the infinity focus, and the sharpness.

It may be close but not as perfect as when checked with a collimator.

Rod