Meniscus Lenses? Another question for Mr. Galli, and others...

[jb7]

I've seen meniscus lenses mentioned here a lot recently-
including Jim Galli's current favourite-

Now, I know what they are,
but in the context of old photographic lenses,
do they have a single element only?
Or is it a lens that contains a meniscus element, among others?
Can a meniscus lens be a cemented group?

And Jim, do you have any idea what is contributing to the qualities your current favourite is exhibiting?

I have a few in front of me now, and will have a look at putting one in a shutter....

I have done a search, but you know, Mohammed, and mountains, and all that...

[Jim Galli]

I've seen meniscus lenses mentioned here a lot recently-
including Jim Galli's current favourite-

Now, I know what they are,
but in the context of old photographic lenses,
do they have a single element only?
Or is it a lens that contains a meniscus element, among others?
Can a meniscus lens be a cemented group?

And Jim, do you have any idea what is contributing to the qualities your current favourite is exhibiting?

I have a few in front of me now, and will have a look at putting one in a shutter....

I have done a search, but you know, Mohammed, and mountains, and all that...

Landscape Meniscus lenses are always a cemented doublet. Even in 1850 they understood that a cemented pair caused the chromatic abberation to improve or vanish. So we call a doublet an achromatic meniscus.

As to quality, it's a crap shoot. Most of them are downright sharp at f 16. And most are throttled to about f12 by their builders. You have to "uncork" them to see what they're going to be like wide open. Wide open you see many different looks, some more subtle than others.

[eddie]

i have a nice jamin landscape lens. sucks in the coverage department.....what kind of coverage you getting jim? when i use the "water house stops" it gets worse. what gives? it is installed correctly i am sure.

e

[Jim Galli]

i have a nice jamin landscape lens. sucks in the coverage department.....what kind of coverage you getting jim? when i use the "water house stops" it gets worse. what gives? it is installed correctly i am sure.

e

Coverage is conservative because they get so wild out in the edges that usually they were vignetted mechanically by longish barrels to the stop. Take the lens out of the barrel and use it in a shutter maybe? You've gotta play with them to see what's going to work. I've got a 6 1/2" Lancaster that I simply popped the group into a wooden lens board and then protected the front a bit with an old Hollywood style flaring lens hood. So now it covers 5X7. Sort of.

[jb7]

Thanks for that Jim, very informative-
I've got the rear group out of a 6" Dallmeyer Enlarging Anastigmat-
it's a cemented doublet, about 75mm fl.

Going to see if I can mount it into my point and shoot plank...

[jnantz]

i have 2 meniscus lenses, they aren't very fancy.
one was harvested off of a box camera and the other off of a folder.
they both had a throttle as jim spoke and they are not doublets.

[jb7]

Sorry, getting mixed up in my nomenclature-
I'm not used to this-

Anyway, it's a cemented group, it goes into a copal 1 (gaffered up around the edge)
and it's around 75mm ƒ/2.5.
Nice and wild open, but seems to tame quickly with stopping down-

Unfortunately, it vignettes in the plank point and shoot, due to the small helical-
maybe I need to make a new camera for it, because it covers 4x5 with a lot of movement...

[Steven Tribe]

This is posted here as it is the latest that thread discussed landscape meniscus objectives and mentioned Jamin! There are the sad remains of a portraits/paysages Darlot/Jamin listed on the famous auction place. Not so sad if you want a landscape set from 1860. This has the original front lens (used at the back with the landscape set-up) and mounting for the washer stops and a single washer. EFL is 18".

I have no connection with the seller - except he used to be a bidding rival in the days when bidders' name were available!

[CCHarrison]

The history of the photographic lens usually begins with Wollaston's menicus lens (or "landscape lens") of 1812, which was an improvement over the bi-convex (double-covex) lens that was commonly used in Camera Obscuras. The bi-convex lens suffers from Chromatic aberration which causes poor sharpness and only direct, on-axis light rays to focus properly.

Wollaston's lens not only changed the shape of the lens to a meniscus type which allowed more light rays to come into proper focus, but by placing a diaphragm in front of the lens, the off-axis rays were prevented from smearing the image sharpness. The diaphragm moderated multiple types of optical aberrations and greatly extend the field of clarity and depth of focus, albeit at the expensive of lens speed. The key to this improvement was the use of the diaphragm to cut off light rays that would otherwise create significant loss of sharpness due to spherical aberrations.

In 1821, Charles Chevalier improved this lens by using a cementing a negative flint glass element with a positive crown element, which allowed the lens to focus visual and actinic light in the same plane - making it the first "achromatic" lens and about f/17 speed. This was the type of landscape lens fitted to Daguerre's original camera, made by Giroux. This type of lens would be used for the next 150 years or so, in simple fixed focus cameras as it was inexpensive to manufacture, provided good sharpness over a moderate field.

the first image on the left is Wollaston's Meniscus and Chevalier's "Landscape" Meniscus on the right..

Dan

[jb7]

Thank you Dan, appreciate that very useful and concise history and explanation-

I'm sure I'll have more questions soon...

joseph