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nkrustev
30-Mar-2011, 03:29
Hi guys,
I have always found help in this forum, so I am writing for help again here.
I recently acquired a Hermagis lens and now I am trying to find more information about it.

The focal length is around 15 inches. It says it is an f/4. It looks like an Eidoscope but I do not think it is. The front element is a cemented double and the rear is air-spaced.

I would be thankful for any information. When was it produced? Why does it say "BIS" at the end of the first row? What does the "Serie I N4" mean? What kind of design is it? Is there literature about it with more technical info? How does it compare to the famous Eidoscopes?

My beat-up iphone is just for size reference only.

http://photo-zona.net/images/user43270/album18102/large/1301480088_fshq9543_6W2C0668.jpg

Steven Tribe
30-Mar-2011, 04:19
Bis is usually used as a "size" modification. There will be a "straight" 4 size as well.
Hergamis made 2 series of the Portrait lens. This series 1 is the "slow" version from F3.4 upwards. The focal lengths which this might be are: 39cm plate,45 for 10x12 and 60 for 12x16. The VM mentions an ad around 1924, assumes they are Petzvals - but doesn't give size numbers.

luphot
30-Mar-2011, 07:02
Hello
here's a doc on hermagis petzval portrait lenses serie I (JL Princelle vademecum)
It appears that n4 bis is 350mm FL with 86mm lens OD witch gives f/4.
It's given to cover 13x18cm (5x7in) but it might cover much more
You can see in the bottom page the same lens as yours with quite same serial n, circa 1894

Stephane
30-Mar-2011, 08:01
So Luphot, since you posted them in another thread, what do these serial# represent?

http://www.largeformatphotography.info/forum/attachment.php?attachmentid=51203&d=1297343859

nkrustev
30-Mar-2011, 08:59
Wow, never doubted you guys.
Mr. Luphot I am having trouble reading the attached pdf (it is quite fuzzy) and the information is very interesting. Would it be too much to ask you to put a bigger version.
Where do you get the "circa 1894"? There is an asterisk next to the 4 BIS size and some explanation about it under the table but I cannot make it out.
How do you think they compare as to the image they produce (series I, II and III).

luphot
30-Mar-2011, 09:43
I tried bigger but attached file is limited to max 650x650 pixels
The data table gives serial # 20000to 35000 from 1890to 1900, so 283834 is just before medium year 1895 (it's an estimation) The date might be written on glass edge (usually "Hermagis Paris 18xx")
Asterisk: "the 4bis reference only appears circa 1914"
This observation doesn't match with data table

Stephane
30-Mar-2011, 10:36
20 000 to 35 000 is different to 283 834
It is a zero extra, which, according to your table would be post-1934.

luphot
30-Mar-2011, 11:16
seems that I need glasses!

Stephane
30-Mar-2011, 11:18
seems that I need glasses!

Wished there was another explanation ;)