|Hugo Meyer wide angle Aristostigmat f7.7, probably studio variant|
The big brass lens in the image above is heavier than a modern SLR, it's sized for a big studio camera. The image shows in its lower left corner a drawing of an Aristostigmat f6.8. Much smaller variants for hand cameras were available, fitting in Compur shutters. Intermediate sized focusable variants may have been the fastest like the Hugo Meyer Aristostigmat 180mm f4.4. The Aristostigmat was patented in 1900 and became a good commercial success when compared to the poor success of Bausch & Lomb's similar patented "Double-Gauss" lens of Alvan G. Clark. The Gauss lens was an achromatic doublet with a little air between the lens elements. The Aristostigmat was made as symmetrical pair of two such Gauss lenses. Only "meniscus" type lens elements were used to reduce reflections. The type of achromats reduced spherical aberration. the new glass sorts used improved reduction of chromatic aberration, and the paired achromats together reduced astigmatism as well as the 6-element Planar of Dr. Paul Rudolph.