Request for information about a Hermagis lens

**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.

**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 n°4 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?

**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 à Paris 18xx")
Asterisk: "the 4bis reference only appears circa 1914"
This observation doesn't match with data table