View Full Version : What is a Goerz Tri-Color?

Matt Miller
17-Jun-2004, 05:51
I was perusing through ebay last night and came across a 7 1/2" CP Goerz Tri-Color lens (Item #3820875120). I have never heard of the Tri-Color. What type of lens is this? For what use was it manufactured?

17-Jun-2004, 06:49
For taking three-color separation negatives with a beam-splitting camera such as the Curtis or National. Probably a Dogmar configuration.

Ernest Purdum
17-Jun-2004, 07:43
I've occasionally seen reference to the Tri-Color before, but never a catalog listing or an advertisement. I'm sure Bill is right about it being basically a Dogmar, which was a frequent choice for the "one-shot" color cameras like those he mentioned. Why a Dogmar? By the time the light got split up into the three colors the effective film speed was pretty low, so to take people pictures a comparatively fast lens was an asset. A primary requisite was the ability to bring all three colors to the same focus. The Dogmar satisfied these criteria better than anything else available at the time. It was a dialyte, the same basic construction as the Artar, the 203mm f7.7 Ektar, and several other highly regarded lenses. Like these, it was relatively unaffected by differing subject/image ratios. This slso would have been significant to the advertising photographers who were frequent purchasers of one-shot cameras.

No lens is perfect and the Dogmar did have one major disadvantage. It had four airspaced elements, therefore eight air to glass surfaces. The lens you saw was very likely made before WW II, therefore uncoated. A user would have to be careful about flare and contrast reduction. Even so, some excellent color photographs were made with one-shot cameras bearing dialyte lenses.

Unless somebody digs up an applicable patent or something, I don't suppose we will ever know if the "Tri-Color" was just a renamed Dogmar or if the name change indicates a slight change of the basic design.

Chad Jarvis
17-Jun-2004, 09:26
I believe later coated versions became the "blue-dot" Trigor.

Jim Galli
17-Jun-2004, 10:06
"I believe later coated versions became the "blue-dot" Trigor."<b>

I have a BD Trigor and it is in every sense a Dagor type. Perhaps with slightly different cell spacing for it's intent, but a Dagor none the less. Obviously it's intent was for some name recognition to it's earlier counterpart in splitting up film colors. But I would bet the earlier one is a Dogmar too. Buy it and find out.

Jim Galli
17-Jun-2004, 10:08
</b> Sorry, turned bold on instead of break........

CP Goerz
18-Jun-2004, 11:39
The tri colour was also an enlarging lens too. Not all lenses could be used with Three Colour Cameras as the rear element of the lens had to be somewhat flush with the lensboard, any intrusion into the camera and it may pop its way through the pellicles and ruin your week.

CP Goerz.