Expert: David Silver - 4/10/2006

Question
I have an old brass camera lens I picked up in Europe (Holland).
There is beautiful hand engraving on it.

No. 5166
Derogy's
V, A picture of a crown, Patent
Paris & Londres
essaye de garranti
par Jacobs
d' Amsterdam
The lenses are about 3 Inches in diameter.
The lens focuses about 9 inches on a wall measured from the stop plate.
It has a slide in stop plate.
I think open for viewing and stopped down for exposing.
The lenses are not coated.
Any idea what this can be?
Casey Veenendaal.


Answer
Hi Casey,

Eugene Derogy of France was an important maker of high quality portrait lenses from the 1860's to 1880's.  The example you found was specifically marked for export, and has the name of the Dutch merchant who sold it.  Typical of lenses from this early period in photography, there is no specific model name by which we can identify the optical formula.  These are usually identified through internal inspection.  However, value more depends on age, size, and condition.  Your example dates from the late 1870's, the end of the "wet plate" period in photography.  The "stop plate" you describe is most likely a Waterhouse stop.  This was a simple method of setting the aperture in the lens, and most lenses came with a cased set of three to six different stops with a range of apertures.  It is not unusual today to find a lens with just one Waterhouse stop left in it after all these years.  Without the stop in place, the effective aperture of most portrait lenses of this type and vintage is around f8 by modern standards.  A focal range of about 9 inches indicates this lens was probably designed to cover up to a 6 1/2 x 8 1/2 inch "full plate" for landscape work and perhaps a 4 1/4 x 6 1/2 inch "half plate" for portraits.  Derogy is just one of MANY such lens makers from this period, and they made far more simple portrait lenses than anything else, so their products are relatively common.  If the lens is in truly excellent overall condition, and it has the mounting flange (the metal gasket that would be attached to the camera with three or four screws, and the lens was then screwed into this), you would expect to get around $300 for it today.

Best wishes,

David Silver