John Vilt 13x18 Petzval lens on Pentax *ist DS

[Spotmatic]

Just for fun... This lens is NOT designed for DSLR's, as it dates from somewhere around 1870. So I didn't expect super sharp pictures (how can it be as I'm using only a fraction of the lens' optics, and it's being used wide open), and there are lots of abberations (purple fringing and CA) too.

I'm not sure about the focal length. It has a back focus of about 19cm (measured from the back element). From front to back element the length is about 85mm; the internal opening is 45mm in diameter.

I just cannot wait to use it on a few wet plates

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[Jesito]

Highly interesting...
Could you please post a picture of the lens on the camera?.

It seems to deliver a nice colouring, even not being tack sharp...

Regards.

Jes.

[Spotmatic]

Jes, I wish I could. In this case I had my Pentax fitted with a bellows unit and 3 extension tubes in front of that. I held the lens firmly against the front extension tube (the lens and the extension tube are around the same in diameter). Actually it's a miracle I got "sharp" pictures this way

[LucisPictor]

Forget about sharpness. These images are amazing!!

Did you boost contrast?

[fotomachi]

[poilu]

great! first time spot post non sharp pics
I guess result can be slightly better with a firm adapter and on a 5D
I am surprised about the PF, I thought older lenses were immune

[Nesster]

[Spotmatic]

Thanks for the tips, Jussi! I'll certainly use them when I find a somewhat smaller Petzval (from a projector, maybe).

In the meantime: here's a monochrome version in which I used only the blue channel (to mimic the collodion process somewhat; that process is only sensitive to blue light). I'm not a B&W man though (in Photoshop that is) so you may or may not like it

[kds315*]

Very well done Peter! I have a few such old brass lenses, lusting for more testing??

[patrickh]

Peter
To quote another thread, you could make an old coke bottle look like a good lens

patrickh

[Spotmatic]

I keep hearing that on all forums I visit. What's that with coke bottles and jam jars? Did I do something wrong to you guys and gals?

[Sevo]

The centre of Petzvals is very sharp, even by modern standards - the design is still used for fast narrow angle, far throw projection lenses. But once you use it on the intended format you should get plenty of CA swirlies. "Portrait" and the ratio between short focal length and large plate size do suggest that it is a soft portrait lens from the age of the first Petzval renaissance (around 1890-1930) rather than a daguerrotype or projection lens, so it should hopefully degrade very nicely on large plates.

Any pointers yet on the maker or dealer (the inscription often is by the latter)? The name might be Dutch or Flemish.

[Spotmatic]

I have disassembled and cleaned the lens today, and I hoped to discover some pencil writings on the outside of the elens elements (like in Darlots). Unfortunately there were none. It made clear however that it's indeed a Petzval: a glued doublet in front and two airspaced elements in the back.

Purely subjective, based on the design of the lens itself and the style of the engravings, I guess that we are indeed looking at a lens that was originally made in the 1870's - 1890's. (My personal opinion: earlier and not later).

I have found exactly one photography-related link to John Vilt: a 1880's field camera. http://collectiblend.com/Cameras/Vilt,John/Field-Camera.html. That's all. The name does not particularly sound Dutch or Flemish; John would be a very uncommon name. I guess it's English or American?

One last question: the "13x18", does that refer to centimeters as opposed to inches?

[Sevo]

13x18cm is one of the basic, first order metric plate sizes, the intermediate in the 9x12/18x24 row, and the focal length matches up as well. It is not impossible that it is of UK origin - they had a mix of metric and imperial measures in photography and optics thanks to the neighbouring French/German/Austrian influence. But the US were very remote from that and I've seen few metric markings on their lenses, so that it is rather a unlikely candidate, unless someone wanted to imitate a (perhaps more highly regarded?) European lens.

An ending in "lt" is linguistically more in line with a Dutch origin than any other Germanic language, and the only likely name source that I could locate for Vilt is a Dutch village, in Limburg. I would not rule out a Dutch origin of the name - John does seem to have been a given name in the adjacent region of Germany, which shares a language with Limburg even today (though growingly rare and endangered).

That said, Google brings up a variety of US John Vilts of Austrian-Bohemian origins, all of them a generation younger than this lens. I can't locate the name in Austrian registers, which rather looks as if the name was assumed (perhaps as a simplified transcription from some Austrian name) at the time of immigration - so if that is the angle to it (which would mean that that name switch had already occurred in an earlier generation), it would be American, after all.

Sevo