Grundlach 8x10 convertible Series numbers?

[cyrus]

I have come into possession of a Grundlach anastigmat 8x10 "Series IV" convertible f 6.8 lens serial no 203648. I've never seen a series IV before, what was the difference between the different series?
The glass on the two elements are very nice, but the shutter sticks. There is a third brass extender of sorts or was that supposed to have a lens in it too?
Any ideas as to coverage?
Much appreciated

[Fotoguy20d]

The series iv is an f6.3 and not convertible. Looks to me like someone put the cells in a series II shutter.

I think it's a IIb Tessar type.

Dan

[Louis Pacilla]

Dan hit the nail on the head with all but one thing. The formula. which looks to be of the Gaussian Type with 8 air to glass surfaces so make sure you use a lens hood as it could flair and lose a bit of contrast but should be plenty sharp. It will not have near the covering power of the TR series II or III.

Here you go.

[cyrus]

Thanks gentlemen!
I thought it was pretty suspiciously described but still, it is a pretty sweet lens. The shutter is being cla-ed, will let you know how the lens works on my 11x14

[Louis Pacilla]

Thanks gentlemen!
I thought it was pretty suspiciously described but still, it is a pretty sweet lens. The shutter is being cla-ed, will let you know how the lens works on my 11x14

Watch out using the Gaussian Type lens 12" fl on 11x14 as it may not cover wide open & you'll have to stop down a good bit I would think simply to not miss your corners shooting straight on. Again, this is NOT the Turner Reich triple convertible 5 glued elements in a cell with 85-90 deg but a double Gauss design which is what your lens is with maybe 50-60 deg stopped down.

[cyrus]

Yes thanks, understood.

The original description was as a convertible which it obviously wasn't when I received it and it looked suspiciously not convetible (even having never tried these sorts of lenses before) but since it was just about the same price or less and I liked the look of the glass anyway, I thought, eh, lesson learned now I'll keep it and play with it.

I actually don't mind falloff and vignetting a bit at all. I don't know why people think bokeh is great but vignetting is bad. They're both just (de)effects, that the artist types appreciate and can use to express themselves, that's all. So while the gearhead in me rebels at the idea, I've discovered that using lens with LESS coverage is actually a good effect on my portraits and even landscape, for a moodier feel. Cheaper than getting the same effect with studio lighting too.

I'm not sure if this was an argument in favor of or against impluse buying crap online though... we'll see how the lens looks in my shots