75mm Hypergon on 8x10"!!

ic-racer · Dec 13, 2023

The Goers 75mm Hypergon lens is being remanufactured.

I just got one and am anxious to try it out.

I have mine mounted on a Shen-Hao FCL810-AC with bag bellows.

Chuck1 · Dec 13, 2023

I'd love to see some images.

grain elevator · Dec 13, 2023

Very cool! Show us the pictures, please!
One question: Shouldn't the propeller be blackened? Is that up to the use like I've read about waterhose stops, to blacken with soot?

Chuck1 · Dec 13, 2023

I was thinking the same thing.

ic-racer · Dec 13, 2023

I was thinking the same thing about painting the spinner black.

Here is the page from the 1913 catalog. Price in 2023 dollars about $1,500 USD.

Screen Shot 2023-12-13 at 8.02.04 PM.png

awty · Dec 13, 2023

Yes very cool

The link doesn't seem to have much info.
Does it have a buld shutter?
Two f-stops?
What's the image circle?

Need to start saving my pennies.

ic-racer · Dec 14, 2023

Most all information about the lens is on the screenshot of the Goerz 1913 catalog (post #5). One of the few things they did different on the reproduction is to put a ball bearing on the spinner.

Not mentioned is the actual amount of extra time needed to expose the edges. This depends on the reciprocity characteristics of the film.

There is a typo in the chart, the "1" is on the wrong row. Rows should read 8x10, then 10x12, rather than 18x10 and 0x12. So the coverage of this lens 000a, 3" focus (75mm), with star, 135 degree, is 8x10, not 18x10!.

Apertures are the same, f22 and f31 (f32). Lens cap is the shutter, etc.

ic-racer · Dec 14, 2023

The numbers on the f-stop scale (48 and 96) are the Goerz equivalent of f22 and f31.6 per the chart below:

ic-racer · Dec 14, 2023

With the configuration in the above picture the lens would not quite focus to infinity.

This is a better configuration. The front standard base tilt is farther back and the lens tilted forward to re-align it with the film plane. Also, the lens needs to be raised to about "20" on the marker to account for the offset hole in the lensboard.

abruzzi · Dec 14, 2023

what I've found online suggests the film should be exposed 80% with the fan spinning and 20% with the fan dropped out of the way. Doing that with very slow film should be managable, but with 100 speed exposed at 50, is a outdoor environment only gets down to 1/15 on a sunny day. Like a center ND filter I'd guess that the contraption will reduce exposure by a few stops. This might get you down to about a half second or so, which is still difficult. Indoors or in darker environments will make it much easier, but I have few of those here. Maybe shooting film with the worst reciprocity may help add some time.

Mark J · Dec 14, 2023

grain elevator said:
Very cool! Show us the pictures, please!
One question: Shouldn't the propeller be blackened? Is that up to the use like I've read about waterhose stops, to blacken with soot?

It could do with being black on the back of the spinner and the three support arms. Any light reflected from the front has no real chance of getting into the imaging light path ( unless you're doing close-ups with the lens - unlikely ! ).

ps. we are on the edge of our seats waiting for a photo from this !

Kino · Dec 14, 2023

abruzzi said:
what I've found online suggests the film should be exposed 80% with the fan spinning and 20% with the fan dropped out of the way. Doing that with very slow film should be managable, but with 100 speed exposed at 50, is a outdoor environment only gets down to 1/15 on a sunny day. Like a center ND filter I'd guess that the contraption will reduce exposure by a few stops. This might get you down to about a half second or so, which is still difficult. Indoors or in darker environments will make it much easier, but I have few of those here. Maybe shooting film with the worst reciprocity may help add some time.

Seems a lens for self-poured dry plates or wet plate photographers...

ic-racer · Dec 14, 2023

The exposure time without the fan is the metered exposure time for the selected aperture and film, just like any other lens.

However, an additional edge exposure is needed with the fan in place. This additional exposure does not affect the center as the fan blocks the center. The additional exposure is only for the edges and is about six times the exposure for the center.

Since it is too fiddly to put the fan up after the initial exposure, the additional edge exposure is done first and then the fan falls down with the pull of a string, at which time the base exposure is accomplished.

The fan is not like a center filter because it totally blocks the central image.

nosmok · Dec 14, 2023

Very cool, can't wait to see results!

abruzzi · Dec 14, 2023

Kino said:
Seems a lens for self-poured dry plates or wet plate photographers...

or paper negatives (or paper positives).

The maker stated that using a Sinar shutter blocks some of the field of view on 8x10, but I don't know if he tried reverse mounting the sinar shutter, something I'll try. (Normally the sinar shutter mounts to the rear of the front standard and the bellows mounts to the rear of the shutter. But it is possible to turn the shutter around and mount it to the front of the standard, and then mount the lens board directly to the shutter. The front standard on a Sinar is about a centimeter thick, so doing this places the lens closer to the shutter by about that amount, but on most lenses, there is too much rear protrusion that it interferes with something.)

DREW WILEY · Dec 14, 2023

It's a spy drone lens. That's the reason for the little helicopter blades.

ic-racer · Dec 14, 2023

The real timing for the exposure is the time from when the fan drops out until the lens cap is replaced.

I practiced these timing sequences before I attempted any film.

3 sec, 1/2 sec
6 sec, 1 sec
12sec, 2 sec.

I waited until near sunset so my exposure was 1 sec at f32. Film is processing now.

I put a knob on the lens cap. It is slippery plastic and at least once, during practice, I dropped it when trying to replace it on the lens.