View Full Version : Lerebours or Voigtlander...?

Scott --
24-Jul-2009, 06:49
Hi, all -

I'm considering two Petzvals right now - a Lerebours et Secretan and a Voigtlander & Sohn #3. The Lerebours is about 210mm, the Voigtlander is about 275mm. Still finding out speed of each lens, but I know nothing of either maker, and was wondering, comparatively, which is likely to be a better optic for portraiture on 5x7.



24-Jul-2009, 07:13
Personally, I'd go for the Lerebours, it is a more uncommon lens, and is probably older. There is not a lot of info on them, but Lerebours worked with some of the early daguerreotype inventors. His family had a history of making optics, and he discovered the color correction of petzvals formula wasn't perfect, so he came up with a better formula that all the makers then copied. I have one from 1855 and it looks like all petzvals, maybe even not finished as nicely as Voigts, but I like having an exotic.

Voigtlander of course was the first to use Petzval's design (and moved to Wein to avoid his patent protection), and for many years were considered the best. I have several and they are very nice, and nicely finished.

Both are excellent. Perhaps the features can decide; if the Voigt has waterhouse slots/stops it might help you on bright days. The Lerebours probably is a dag lens, with no stops. Determining if one has the later color correction is difficult without using it. The serial numbers won't help much, but a later one (post about 1850 I believe...) probably has it. Again, these are both top lenses, either would be fine.


24-Jul-2009, 07:28
I remember now, the color correction was fine, but the UV focus was at a different point. Very early lens users were having to focus, then tweak the focus a little more so the dag was correct....About 1840

"Lerebours learned of the problems with the colour correction of the Petzval design noted by Townson, and by Claudet, who operated in London and Paris, early on. The difficulty was that correction of the colours to a visual focus did not coincide with the actinic or photographic focus. He designed Petzval Portrait Lenses with improved colour correction in 1840." (Vade Mecum)

Petzval Paul
24-Jul-2009, 07:40
I think that the 275mm FL would give a better perspective on 5x7. 210mm is OK... but just OK. Certainly the longer Fl would be more flexible so you could get in close for tighter shots.

Jason Greenberg Motamedi
24-Jul-2009, 08:20
In my experience based on a rather limited sample (maybe four Lerebour and a dozen Voigtlaender) Lerebours made better (Petzval) lenses than Voigtlaender. However, both 8" and 9" would be rather short for 5x7--better for 4x5 or 1/4 plate. For 1/2 plate or 5x7 I would look for an 11" lens. My lens of choice for 5x7 would be a Dallmeyer 3B.

Scott --
24-Jul-2009, 09:02
Thanks, guys. I appreciate the info and input. FWIW, my current favorite portrait lens on 5x7 is a 210/5.6 Sironar-N (this (http://www.largeformatphotography.info/forum/showthread.php?p=478551#post478551) was taken with the 210, though I cropped the result a little). I'd think the 210/275 Petzvals would give me a similar perspective. I think the determining factor, though, is whether the Lerebours has a WH slot. I need the ability to stop down a little.

Unrelated, but I just found out that my local 'pro' lab, DCC Photo in Reading, PA, apparently has gone out of business. Website's gone, phone's been disconnected. I'm bummed... :(

Petzval Paul
24-Jul-2009, 10:04
If you are shooting film... yes, water-house stops are important. I think Jason's recommendation of an ~11" lens is certainly valid, but with a longer FL you'd miss out on some swirls and that's probably 1/2 the reason you'd want to shoot a Petzval, anyway. I do think 210 is a bit limiting, though. Moreover, Petzvals don't have much coverage. 275 should be about right, IMHO.

25-Jul-2009, 11:54
From the publication "The Photographic Art Journal" 1851, an article by Antoine Claudet (translated from French) stated:

"In Paris, M. Lerebours and Secretan are renowned for lenses of longer focus, which are better adapted for taking views than any I have yet tried.* From the beginning of photography, it was well known that the effective rays being the most refrangible, had a shorter focus than those producing the white light; and for this reason, Daguerre, himself recommended the use of achromatic lenses in which all the rays were supposed to converge at nearly the same focus. All camerae obscurae were furnished with achromatic lenses, and constructed so that the plate could be placed exactly at the same distance on the ground glass upon which the image had appeared the best defined. But with these camera obscura it was very difficult to obtain a photographic image so perfect as that seen on the ground glass; and it was only now and then, and as if by accident, that good pictures could be produced.

I soon recognized that anomaly, and imagined that it was owing to some errors in the respective position of the two frames ; one holding the ground glass, and the other containing the plate, which by warping, or some other causes, might have been shifted to different distances from the object glass.

Not being able to assign another reason for the errors, I constructed a camera obscura in which the ground glass and the plate were exactly placed in the same frame. In doing so, I hoped to avoid the least error or deviation. But to my surprise the more correct I was in my adjustment, the less I could obtain a well defined Daguerreotype picture. This proved to me that I had to seek for another cause of the difficulty ; and before going any further, I decided to try if the visual focus did or did not really coincide with the photogenic focus. For the experiment, I placed at a distance from the camera, with which I was accustomed to take pictures, several screens on different planes, removed one from the other 3 or 4 inches. These screens being covered with black lines, could be distinctly seen on the ground glass. I tried the focus on one of the screens, and, after having raised the ground glass, I placed it in the same frame for the prepared plate. In examining the image obtamed upon the plate, my surprise was quite as great as my joy, when I saw that the screen which had given the image well defined on the ground glass, was confused oh the Daguerreotype plate, and vice versa. I was no longer in doubt. I had discovered the reason of the difficulty which had prevented success. The photogenic focus had not coincided with the visual focus in my camera obscura, although the lens was considered perfectly achromatic. But the most surprising feature of that discovery was, that the photogenie, was longer than the visual focus. On first consideration it should have been shorter, as the rays operating in photography are the most refrangible. Although at first I could not comprehend the cause of this anomaly, it was sufficient for me to know that, in order to obtain a Daguerreotype picture perfectly well defined, I had only to set the focus on the ground glass for an object nearer the camera than the distance indicated by the experiment with the various screens.

Continuing my experiment, I found some lenses in which the photogenic focus was shorter, and some others in which the two coincided.

As soon as I had discovered the existence of two foci, I wrote a communication of the fact to the Academy of Sciences and to the Royal Society of London in May 1844. Since that time photographers have been able to find the true photogenic focus of their camera ; and opticians, who, at first, would not submit to the idea that their lenses were defective, have at last studied and considered the question, trying to construct lenses in which the two foci should agree.

M. Lerebours of Paris, was the first, who at my suggestion investigated the subject ; and he communicated a paper to the Academy of Sciences, in which he explained the cause of the difference. He stated that by altering the proportion between the angles inscribed in the curves either of the crown or flint glass, he could render, at will, the photogenic focus longer or shorter than the visual focus, and by the same means bring them to the same point. M. Lerebours was perfectly right, so far as the result applied to the correction of chromatic aberrations; but if according to the density of the two glasses, certain curvatures are required to correct the spherical aberrations, could we with impunity alter these curvatures only for the purpose of changing the. directions of the most refrangible rays ? For this reason I have always preferred lenses in which the spherical aberration is the most perfectly corrected, without caring whether the photogenic rays coincided or not with the visual rays, having the means of ascertaining how I could obtain on my Daguerreotype plate the best defined image. Another consideration confirms me in my opinion. Having observed that the red, orange, and yellow rays were opposed to the action of photogenic rays, when they existed in a certain proportion.* I am of opinion that every combination, by which the photogenic rays alone are condensed upon the plate, and the others dispensed on the spaces more or less distant from the photogenic points renders the action much more powerful. Rapidity being the principal object in photography, I prefer lenses in which tin two foci are separated, although the operation is a little more difficult and requires greater care.

The question of the photogenic focus is involved in another kind of mystery, which requires some attention. I have found that with the same lenses there exists a constant variation in the distance between the foci. They are never in the same relation to each other ; they are sometimes more or less separate ; in some lights they are very distant, and in some others they are very near, and even coincide. For this reason I constantly try their position before I operate. I have not been able as yet to discover the cause of that singular phenomenon, but I can state positively that it exists. At first I thought that some' variations in the density or dispensive power of the atmosphere might produce the alteration in the distance between the two foci; or that when the yellow rays were more or less abundant, the visual rays were refracted on different points on the axis of the foci, according to the mean refrangibility of the rays comprising white lic'ht at the moment. But a new experiment has proved to me that these could not be the real cause of the variation. I generally employ two object-glasses; one of shorter focus for small pictures, and the other of longer focus for larger images. In both the photogenic focus is longer than the visual focus ; but when they are much separated in one, they are less so in the other; sometimes when they coincide in one, they are very far apart in the other, and sometimes they both coincide. This I have tested every day during the last twelve months, and I have always found the same variation. The density of the atmosphere or the color of light, seems to have nothing to do with the phenomenon, otherwise the same cause would produce the same effect in both lenses. I must observe that my daily experiment upon my two object-glasses are always made at the same moment, and at the same distance for each ; otherwise any alteration in the focal distance would disperse, more or less, the photogenic rays, which is the case, as it is easy to prove. The lengthening or shortening the focus, according to the distance of the object to be represented, has the effect of modifying the achromatism of the lenses. An optician, according to M. Lerebour's calculation, can at will, in the combination of the two glasses forming an achromatic lens, adapt such curvatures and angles in both, that the visual focus shall coincide with the photogenic focus ; but he can obtain this result only from one length of focus. The moment the distance is altered, the two foci separate, because the visual and photogenic rays must be refracted at different angles in coming out of the lens, in order to meet at the focus given for one distance of the object. If the distance is altered, the focus becomes longer or shorter, and as the angle at which various rays are refracted remains nearly the same, they cannot meet at the new focus, and they form two images. If the visual and photogenic rays were separated parallel to each other; in coming out of tho lens, they would coincide for every focus ; but thig is not the case.* It seems therefore very difficult to construct lenses in which the two foci will agree for all the various distances, until we have discovered two kinds of glasses, in which the densities or the refractive power will be in the same ratio as the dispersive power."


25-Jul-2009, 17:23
This is a very interesting read to me, and it's nice to hear the clear thinking and experimentation as Claudet discovers the problem, then considers Lerebours suggestions to solve it. I believe history showed that Lerebours was at least partially right, because his methods were adopted by lens makers.

Being no optician, I wonder if he was right; that spherical aberrations are affected when a technician tries to synchronize the visible and what he's calling "photographic" focuses. Could he have been seeing a difference because the daguerreotypes (and collodion) predominate in the blue and UV spectrums?

More interesting is his hypothesis that even if the two can be synced, they will only be so for certain focal lengths, not all. I don't recall a lot of anecdotal discussions that "xyz lens is better at portrait lengths, not closeups..." or "it's very sharp at landscape distances..." etc. But perhaps there is something going on there? What I have read is that before the Lerebours calculations were adopted, photographers did what Claudet describes; focused, then changed the length a tad to compensate for the difference. I have not had to do this with any of my lenses, though some magic lantern lenses were so unsharp they may have needed something like this.....