Please help with Darlot lens

[photojournalism]

Hello!
Can anybody provide any info for this lens 360307003629 ?
Seller said that rear is cemented doublet and front is 2 air spaced. On the face of it's a classic Petzval lens, but no reason to distrust the seller.
I have two ideas 1. This is incomplete lens 2. This is early convertible lens with rear landscape lens and with front portrait adjustment.
Any ideas?
Thanks.

[Fotoguy20d]

I really don't think its an "early tessar". It could be a backwards petzval. But, at that price, I'd be very leary of buying it unless I knew exactly what I was getting. I have a Darlot projection lens, around 8" focal length (to the mid point) - it's got the normal construction. FWIW, mine covers 4x5 with some swirling and seems to be able to cover 5x7 with good petzval characteristics, so if its 10" it should cover more. Maybe a darlot expert could provide some more insight.

Take a look at these:

http://www.largeformatphotography.info/forum/showthread.php?t=67247

http://www.largeformatphotography.info/forum/showthread.php?t=66676&highlight=reversed+petzval


http://www.largeformatphotography.info/forum/showthread.php?t=66626&highlight=petzval+backwards

[photojournalism]

Thanks for the links but they tell about different composition of rear Petzval element.
And we have another formula, so I'm interesting is it original or not?
I have never heard about this lens design were the front is air spaces and rear is doublet.
Also you can see that the rear element is bigger, so you can't change it with the front one - otherwise it would be too simple.

[BarryS]

It's a Darlot Petzval regardless of the seller's claims. You can't discount the seller's claims entirely because they sell a lot of barrel lenses, but the front and rear groups were likely switched at some point. The brass bindings for the cells don't have to have the same thread side because the glass elements can be easily removed and swapped in Darlot Petzvals. A reversed Petzval will form an image that may not be a lot different than the original configuration. Maybe the previous owner did it to have a home brew landscape configuration when the "front cell" was removed.

[CCHarrison]

I agree with Barry - element groups are backwards and just need to be reinstalled with the proper orientation.

Dan

[photojournalism]

Sounds good, if all elements were in the same size in Darlot Petzval lenses. Thanks.

[Fotoguy20d]

Sounds good, if all elements were in the same size in Darlot Petzval lenses. Thanks.

I don't know why you're so sure the lenses are different sizes. The front looks bigger because of the hood perhaps, but I suspect they are the same diameter. Contact the seller and ask him to measure the diameter of the glass on each.

[Steven Tribe]

I was in contact with the seller within a few hours of it being listed. Mostly to correct the "AD" funny conclusion - but also to say that it must be a Petzval (or the remains of one) 'cos it couldn't be anything else from Darlot that looks like this.
He couldn't alter the listing as a "spoiler" (someone who knows that there is a bad mistake in the listing which may reduce interest) had already bid.
He said "the powers that be" say it had a cemented doublet at the back . I replied that the front and rear cells must have been switched.
This not the first time that a MW listing has become a farce.

[photojournalism]

Yes, AD interpretation was great! But if serious, I'm afraid that lens could be modified or collected from different lenses, if the seller is not expert. Any way, thanks all for answers.

[Richard Rankin]

I was in contact with the seller within a few hours of it being listed. Mostly to correct the "AD" funny conclusion - but also to say that it must be a Petzval (or the remains of one) 'cos it couldn't be anything else from Darlot that looks like this.
He couldn't alter the listing as a "spoiler" (someone who knows that there is a bad mistake in the listing which may reduce interest) had already bid.
He said "the powers that be" say it had a cemented doublet at the back . I replied that the front and rear cells must have been switched.
This not the first time that a MW listing has become a farce.

I sort of thought they might do that on purpose to generate interest by making people think they have found a bargain. It gets them queries and postings which would make people think there is a lot of interest and activity on the item and drive up the bids.
Richard

[Steven Tribe]

I can garantee that there is no devious plan behind the listing. No one is fool enough to say "this is not a Petzval" and hope for bidding success.
The messages I have received from MW (I have bought from their website) suggest the right-hand doesn't know what the left-hand is doing.

[Richard Rankin]

I've also bought from them a couple of times over the years and never had any problem, but doubt I ever asked many questions of them and never paid top dollar for anything from them.

I find these kinds of listings, and many others like them, quite amusing, but the 'AD = quick acting' has to be one of the best. Ebay has provided a brand new forum for snake oil salesman who somehow provide incredibly detailed information on one hand and then try to hide behind their ignorance at the same time. You gotta love the internet...

[Mark Sawyer]

Or sometimes sellers don't have a clue...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260648561402&ssPageName=STRK:MEWNX:IT

[Steve M Hostetter]

Or sometimes sellers don't have a clue...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260648561402&ssPageName=STRK:MEWNX:IT

Mark,, this is hilarious :D

[Steven Tribe]

Well actually there is a real sea chart magnifying glass - with the 3 adjustable legs - listed at the moment. To start with, the seller had no idea what it was.
Engraving gives a lot of difficulty. Darlot has been Parlor quite often and Voigtländer very often has a new partner, John. Of course, many photographic stores have been acredited with lens manufacture in their backroom.

[Mark Sawyer]

Well, at least now I'll have a way to view my vintage ship boat maps... :)