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Meniscus lens on Six-20 Folding Brownie
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PostPosted: Fri Apr 13, 2007 3:11 pm    Post subject: Meniscus lens on Six-20 Folding Brownie Reply with quote

Well, I bought one - for the whooping sum of 8 Euros! Laughing

Looks quite old and probably not working - in any case I bought it for the meniscus lens. I will take it off and try some mad experiment with my 5D !

Wish me luck (I need it!!!)


PostPosted: Fri Apr 13, 2007 3:22 pm    Post subject: Reply with quote

I cross my fingers, I never heard about this lens.


PostPosted: Fri Apr 13, 2007 3:30 pm    Post subject: Reply with quote

Attila wrote:
I cross my fingers, I never heard about this lens.


Take a look at what Veijo has done with a Meniscus Achromat !!!

http://www.galactinus.net/vilva/retro/eos350d_meniscus.html


PostPosted: Fri Apr 13, 2007 3:41 pm    Post subject: Reply with quote

Looks a lens with haze or full covered with dust Sad


PostPosted: Fri Apr 13, 2007 4:07 pm    Post subject: Reply with quote

Attila wrote:
Looks a lens with haze or full covered with dust Sad


Look at the bottles images. No hazy lens of today will give that bokeh.
Of course it's not the lens you will use for sharpness. But for bokeh effects and for romantic portraits, it may just be THE lens.


PostPosted: Fri Apr 13, 2007 4:14 pm    Post subject: Reply with quote

Yes, right. Try to cover an old not used lens with cream around the center, perhaps effect is same Smile Kidding but perhaps true.


PostPosted: Fri Apr 13, 2007 4:32 pm    Post subject: Reply with quote

Attila wrote:
Yes, right. Try to cover an old not used lens with cream around the center, perhaps effect is same Smile Kidding but perhaps true.


Well, the Meniscus is (at least for what I can understand, someone else will be able to be more precise) a non-corrected lens. As you know, the non-correction of optics is a basic ingredient for an amazing bokeh. No lens of today, not even the cheapest one, is not corrected. They all are corrected against optical defects. Is the degree, or control, of the corrections (especially peripherical ones), that can make the difference between the lenses of today. But because of what just said above, no lenses of today will ever be able to give the bokeh of these very old lenses, because all modern day lenses are corrected.


PostPosted: Fri Apr 13, 2007 4:37 pm    Post subject: Reply with quote

I always learn something thank you for your detailed explanation.


PostPosted: Fri Apr 13, 2007 5:08 pm    Post subject: Reply with quote

Attila wrote:
I always learn something thank you for your detailed explanation.


I am not sure that what I said is correct !


PostPosted: Fri Apr 13, 2007 5:12 pm    Post subject: Reply with quote

Let we see might be other member has different opinion.


PostPosted: Fri Apr 13, 2007 6:09 pm    Post subject: Reply with quote

The pictures taken by Veijo with that lens, look" Ethereal", using his word, .
My words - stunning images.

Sorin


PostPosted: Fri Apr 13, 2007 6:33 pm    Post subject: Reply with quote

Hi!

I like these pictures a lot and I can understand what you want to do, Orio.
Actually, I am waiting to get two large format lenses to experiment at my EOS with. Wink

A Meniscus lens is a single lens where, strictly spoken, the concave side has the same curve as the convex site. This kind of lens is neither converging nor diverging.
In astronomy they speak about a positive meniscus lens which is thicker in the middle than at the edges and serves as a converging lens and a negative meniscus lens that thickens toward the edges and works as a diverging lens.

However, there are some "Achromatic Meniscus types" that are built as a "two elements in one group" configuration. As far as I know, the old Kodak pocket cams had such a corrected set-up.

Oh, I love to chat about lenses and lens design, if only I knew more about it. But I am learning... Wink

Carsten

P.S.: More information here: http://en.wikipedia.org/wiki/Lens_(optics)


PostPosted: Sat Apr 14, 2007 3:49 am    Post subject: Reply with quote

Thanks Orio.. for triggering.. I was planning to buy from long time... But always end up buy 50s folding camera, folding... so cant be used on SLR.. more like oldie rangefinder...
Just today, I bought 1917-18 manufactured camera for a big fortune, $17.
http://www.brownie-camera.com/85.shtml

as the camera was used in 1918, so its one of the first one... will show the results, once I will get...


PostPosted: Sat Apr 14, 2007 4:59 am    Post subject: Reply with quote

Ballu wrote:

Just today, I bought 1917-18 manufactured camera for a big fortune, $17.
http://www.brownie-camera.com/85.shtml

as the camera was used in 1918, so its one of the first one... will show the results, once I will get...


The 2C uses size 130 film, which is obsolete. The frame size is 2 7/8 x 4 7/8, which means that the camera can/has to be adapted to use size 120 film. This can be done with 5/8" worth of spacers for the film spools and some tinkering. Do this, and you'll have a 6 x 12 pocket camera Smile

Veijo


PostPosted: Sat Apr 14, 2007 5:23 am    Post subject: Reply with quote

vilva wrote:
The 2C uses size 130 film, which is obsolete. The frame size is 2 7/8 x 4 7/8, which means that the camera can/has to be adapted to use size 120 film. This can be done with 5/8" worth of spacers for the film spools and some tinkering. Do this, and you'll have a 6 x 12 pocket camera Smile

Veijo

Veijo, I am fan of your site and art. I am planning to out this on 350D. But I wont break the camera, unless it will be totally wreck...
The camera has Autographic lens.
Do you have some information, how this lens will behave on 350D.
But hearing 6x12 size, I am having second thoughts now.... why not keep just for film...
Your views will be really appreciated...
-Ballu..


PostPosted: Sat Apr 14, 2007 7:17 am    Post subject: Reply with quote

Ballu wrote:
vilva wrote:
The 2C uses size 130 film, which is obsolete. The frame size is 2 7/8 x 4 7/8, which means that the camera can/has to be adapted to use size 120 film. This can be done with 5/8" worth of spacers for the film spools and some tinkering. Do this, and you'll have a 6 x 12 pocket camera Smile

Veijo

Veijo, I am fan of your site and art.

Smile

Quote:
I am planning to out this on 350D. But I wont break the camera, unless it will be totally wreck...


The lens is usually very easy to remove without wrecking the camera: just open the back and loosen the retaining ring, and the whole lens head will get off.

Quote:
The camera has Autographic lens.
Do you have some information, how this lens will behave on 350D.


The lens isn't Autographic. This term refers to a type of film with a special backing. At the back of the camera, there is a covered opening which can be opened after exposing a frame in order to scratch some markings for exposure through this backing - i.e. "manual EXIF". The Autographic cameras came with a metal stylus for this purpose.

The 2C was made with three types of lenses, either an Achromatic (probably a Achromatic Meniscus) or a Rapid Rectilinear, which is a symmetric design, or a Kodar, which is an astigmatic lens. I have used the first two these types on a 350D, and they have very different characteristics, the RR is much better corrected. The Kodar is probably even better than the RR. The focal length of the 2C is probably longer than 140mm - a medium tele for the 350D, which will use only a very small section from the middle of the frame. The image quality depends very much on the type of the specific lens and the focusing mechanism you construct for the lens - from bad Lensbaby type IQ to something "too good" (not different enough considering all the trouble.)

Quote:
But hearing 6x12 size, I am having second thoughts now.... why not keep just for film...


The 6x12 size is more like just a curiosity because the IQ doesn't match it. All the lens aberrations will be more visible, and you'll have problems with film flatness. However, the resulting photos will certainly look different than any photos you get out of the 350D.

Veijo


PostPosted: Sun Apr 15, 2007 4:48 am    Post subject: Reply with quote

Orio wrote:
Attila wrote:
Yes, right. Try to cover an old not used lens with cream around the center, perhaps effect is same Smile Kidding but perhaps true.


Well, the Meniscus is (at least for what I can understand, someone else will be able to be more precise) a non-corrected lens. As you know, the non-correction of optics is a basic ingredient for an amazing bokeh. No lens of today, not even the cheapest one, is not corrected. They all are corrected against optical defects. Is the degree, or control, of the corrections (especially peripherical ones), that can make the difference between the lenses of today. But because of what just said above, no lenses of today will ever be able to give the bokeh of these very old lenses, because all modern day lenses are corrected.


These Kodak Meniscus lenses aren't completely uncorrected, they achromats, i.e. some of the chromatic aberrations have been corrected. However, the spherical aberrations and coma are still there plus a lot of flare. Many of the cameras limit the aperture to be smaller than the basic aperture of the lens in order to prevent the most excessive aberrations. The VPKs have a removable limiting plate and the aperture mechanism in front of the lens, the Six-20 Folding Brownie seems to have them behind the lens although I'm not sure whether there is an extra aperture plate. However, for the "best" results, you ought to get only the lens to use it as wide open as possible, which isn't very fast, anyway. Also focusing will be easier wide open, e.g. the VPK Meniscus is only something like f/6 even after removing the aperture limiting plate and it isn't exactly what you'd call a high contrast lens.

Veijo