Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!

SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Aldis Uno Anastigmat 4.5/4"
View previous topic :: View next topic  


PostPosted: Fri Nov 30, 2007 5:51 pm    Post subject: Aldis Uno Anastigmat 4.5/4" Reply with quote

Last night I extracted the lens from the Ensign Carbine and fixed it to an M42 extension ring so I could mount it on the bellows. To-day was cold, a few degrees below zero Centigrade, and rather windy, and the Sun sets very early, at about twenty minutes past three PM. It had been cloudy, but just before sunset the sky cleared, somewhat, so I had a few rather uncomfortable minutes to take some shots, the 350D at ISO 400 and rather slow speeds given the focal length of the lens and the circumstances - still I had to push the photos one stop so they are a little bit noisy.

Here are the decent shots downsampled and unsharpened plus links to two full-scale, also unsharpened photos. The target is the Cathedral, as usua.







Full-size: http://galactinus.net/vilva/retro/eos350d_uno_files/u8353.jpg







Full-size: http://galactinus.net/vilva/retro/eos350d_uno_files/u8358.jpg

Judging on the basis of these photos (ignoring the noise, which is no fault of the lens), the Uno seems to be a quite decent lens with a rather good contrast due to the minimal number of air/glass surfaces. Now I'm impatiently waiting for more light and perhaps slightly more comfortable circumstances for more test shots.

Veijo

PS. it is a pity the camera was almost certainly beyond repair. When I examined it more closely, I found out that it has a rather clever pressure plate system: the cover of the red frame counter window at the back is connected to the pressure plate so that when the window is uncovered, the pressure plate is released, and when the window is covered, full pressure is applied to keep the film firmly in place.


PostPosted: Fri Nov 30, 2007 6:00 pm    Post subject: Reply with quote

Quote:
Judging on the basis of these photos (ignoring the noise, which is no fault of the lens), the Uno seems to be a quite decent lens with a rather good contrast due to the minimal number of air/glass surfaces. Now I'm impatiently waiting for more light and perhaps slightly more comfortable circumstances for more test shots.


Veijo, really you think these pictures show a good contrast? The tonal range seems quite compressed to me. Maybe it's the time of the day and the available light.
What impresses me, instead, is the resolvance. I can read a lot of detail from these emages, judging on the full size samples you provide. So much detail, it does not have much, or at all, to envy from expensive contemporary lenses. I even think that with some local contrast enhancement, the detail would "pop-out" even more. Perhaps even a simple adjustment of black and white points would be enough to make of these pictures, images that could be taken (with regards to detail rendition) with some expensive lenses of today.

-


PostPosted: Fri Nov 30, 2007 7:05 pm    Post subject: Reply with quote

Orio wrote:
Veijo, really you think these pictures show a good contrast? The tonal range seems quite compressed to me. Maybe it's the time of the day and the available light.


The culprit is the available light with a very low contrast. The whites weren't really whites, and there are no blacks to speak of. The light was very diffuse, and there were no very deep shadows. I was actually astonished when I saw the photos. There isn't very much difference in the tonal range of these photos and some taken under almost but not quite as bad circumstances with e.g. the 2.8/60 Macro-Elmarit, and even with the noise, the micro-contrast is pretty good, see e.g. the columns in the second full-size photo. With four air/glass surfaces, the attenuation of an uncoated lens system might be about half a stop, which is just discernible. The glass of the lenses is also very clear, and there are no scratches or dust.

Quote:
What impresses me, instead, is the resolvance. I can read a lot of detail from these emages, judging on the full size samples you provide. So much detail, it does not have much, or at all, to envy from expensive contemporary lenses. I even think that with some local contrast enhancement, the detail would "pop-out" even more. Perhaps even a simple adjustment of black and white points would be enough to make of these pictures, images that could be taken (with regards to detail rendition) with some expensive lenses of today.


Well, adjusting the balck and white points would certainly enhance the photos, but then they wouldn't be anything like the reality was, the contrast was so low that I had trouble focusing even though this lens is quite easy to focus at f/4.5. I was afraid that all the photos would be out of focus, but only one photo of twelve was clearly misfocused.

There certainly is enough resolution even for the 350D. The text on the book in the first full-size photo is about as sharp as I've ever seen. The photo was taken at 1/250s with hands shaking of cold, and still it doesn't much differ at this detail from a photo taken with the 2.5/105 Nikkor at 1/1250s, see http://galactinus.net/vilva/retro/eos350d_n105_files/n105_7455.jpg , which has a better contrast, of course, being taken in full sunshine.

I have put local contrast enhanced versions of the Uno full-size photos at

http://galactinus.net/vilva/retro/eos350d_uno_files/u8353_lce.jpg and http://galactinus.net/vilva/retro/eos350d_uno_files/u8358_lce.jpg

Veijo


PostPosted: Fri Nov 30, 2007 7:52 pm    Post subject: Reply with quote

I am looking forward to seeing what this lens can do in a good light condition. I am convinced it will be a very positive surprise.
Thanks for sharing these images. I learned a lot from your series with ancient lenses.

Does this lens show any colour aberration of purple fringing (what is the correct definition, by the way?) I don't seem to see any. if so, then the performance would be absolutely impressive!


PostPosted: Fri Nov 30, 2007 8:18 pm    Post subject: Reply with quote

Orio wrote:
Does this lens show any colour aberration of purple fringing (what is the correct definition, by the way?) I don't seem to see any. if so, then the performance would be absolutely impressive!


There are very few high contrast edges in these photos so it is hard to tell for sure. I examined all the photos I had taken, and looking very closely and critically I could find a hint here and there, however, nothing that would be visible on a print, I think. Tentatively I'd say that this lens is in the same category as the APO-Lanthar and the Cooke triplets, i.e. perfect enough for all practical purposes. The contrast ought to be slightly better than that of the Cookes, which have two air/glass surfaces more, and consequently all the colour aberrations might be slightly more clearly visible - when not masked by sensor noise.

Veijo


PostPosted: Fri Nov 30, 2007 8:21 pm    Post subject: Reply with quote

vilva wrote:

There are very few high contrast edges in these photos so it is hard to tell for sure. I examined all the photos I had taken, and looking very closely and critically I could find a hint here and there, however, nothing that would be visible on a print, I think. Tentatively I'd say that this lens is in the same category as the APO-Lanthar and the Cooke triplets, i.e. perfect enough for all practical purposes. The contrast ought to be slightly better than that of the Cookes, which have two air/glass surfaces more, and consequently all the colour aberrations might be slightly more clearly visible - when not masked by sensor noise.
Veijo


I am really impressed by this performance, because some of the most expensive lenses that I have - namely Leica and Contax- sometimes show CA in surely higher amount than this.
Veijo I am a bit confused about the "purple fringing" definition, is it the same as colour aberration, or a different thing?
-


PostPosted: Fri Nov 30, 2007 9:07 pm    Post subject: Reply with quote

Orio wrote:

I am really impressed by this performance, because some of the most expensive lenses that I have - namely Leica and Contax- sometimes show CA in surely higher amount than this.

Veijo I am a bit confused about the "purple fringing" definition, is it the same as colour aberration, or a different thing?


Purple fringing can be caused by certain types of chromatic aberration but in digital photography also by the sensor or sensor-lens interaction, especially with very high contrast lenses under high contrast conditions, which is one explanation for the better behaviour of the older lenses. Lens design is a science but also an art and a balancing act. Probably a lens cannot be perfect in all respects, and the art is in making the correct compromises. Perhaps in the olden times the limited accuracy of the available methods took care of the compromises, at least to an extent. Anyway, the more I use the old lenses, the safer I feel with them. Using them means accepting certain limitations, a rather limited range of focal lengths, limited speed, lower contrast, but on the other hand, all tools have limitations, TINSTAAFL (There Is No Such Thing As A Free Lunch.)

Veijo

See http://www.dpreview.com/learn/?/Glossary/Optical/chromatic_aberration_01.htm

http://en.wikipedia.org/wiki/Chromatic_aberration

and http://en.wikipedia.org/wiki/Purple_fringing


PostPosted: Fri Nov 30, 2007 9:19 pm    Post subject: Reply with quote

Quote:
Anyway, the more I use the old lenses, the safer I feel with them. Using them means accepting certain limitations, a rather limited range of focal lengths, limited speed, lower contrast, but on the other hand, all tools have limitations


And the more you show us your results, the more you are convincing me of what you say!
If only I wasn't such a total dumb at handiwork. Rolling Eyes

Thanks for the links, they were very informative - I seem to undestand a little discrepancy on the concept of purple fringing from dpreview to Wikipedia - as the former seems to identify it precisely with the microlenses, while the latter seems to describe the purple fringing more as one of several possible visible actualizations of chromatic aberration, rather than a specific type of chromatic aberration per se.


PostPosted: Fri Nov 30, 2007 9:46 pm    Post subject: Reply with quote

Even after having read your explanations, I'd like to state my first impression:
I also would have said, low in contrast but high in resolution and a very fine, almost "noble" detail rendering.

Looking forward to seeing some results in good conditions.


PostPosted: Fri Nov 30, 2007 11:57 pm    Post subject: Reply with quote

Amazing what results you are getting from these ancient lenses. I for one would never have given any of them a second thought. Apart from the light effects, I am not convinced about any serious sharpness in these samples, but wait for the good light versions


patrickh


PostPosted: Sat Dec 01, 2007 8:44 am    Post subject: Reply with quote

LucisPictor wrote:
Even after having read your explanations, I'd like to state my first impression:
I also would have said, low in contrast


I'd never insist that an old uncoated lens has anything like the contrast of an MC lens, that would be absurd. Probably the contrast bottoms at something like eight stops, but that is enough for most practical purposes, especially if one makes prints - the dynamic range of a print is less than seven stops, often hardly more than six stops. However, an original eight stops is plenty given the possibilities of adjusting the contrast during PP, e.g. Ansel Adams did most of his work within this limited contrast space.

EDIT: even five stops on paper is near the upper end of the scale as it means something like 97% reflectivity at the white end and 96% absorbance at the black end. The white end is easier to slightly improve, but getting higher absorbance is difficult. Anyway, I'd say that a six stop dynamic range print is already more or less impossible.

Quote:
high in resolution and a very fine, almost "noble" detail rendering.


Here is a crop after some noise reduction and very slight sharpening:



Then two bookshelf crops at f/4.5, both unsharpened and without any lens specific contrast adjustment, the first one is an upper left corner crop with low and medium contrast detail. The fall-off at the left is due to the light coming from the right and gives an idea of the low contrast behaviour of the lens.


The second crop is from near the center of a frame. The ruler was tilted to afford some leeway in focusing and also to minimize contrast lowering reflections. On a 20 cm x 30 cm print, the dimensions of this crop would be 42 mm x 42 mm, a 14x magnification relative to the original size of 3 mm x 3 mm on the sensor; on screen the magnification is much higher.



Veijo


PostPosted: Sun Dec 02, 2007 9:28 am    Post subject: Reply with quote

Here is the Uno mounted on my 350D, at about infinity focus:



I had to use a reversal ring to mount it on the bellows as I didn't have a short enough extension ring available at the moment - a 7 mm ring would have been about optimal.

Veijo