New 75mm Hypergon Lens

[Kiwi7475]

This is what I was going to do.

With the fan 'up' and timer ready, place my hat over the lens, pull the dark slide, start spinning the fan while holding the dark slide, and remove the hat and start counting. When the 'edge' exposure is done, flip the fan down and keep counting until the end. Then put my hat over the lens again and insert the dark slide.

How to do flip it without getting your hand/fingers into the field of view of the lens?

[Kiwi7475]

How to do flip it without getting your hand/fingers into the field of view of the lens?

Maybe I can answer my own question— the lever that flips open the star has a hole so a simple string can probably do the job by pulling on it at the right time…

Just need to be real gentle to make sure nothing shifts in the camera when you pull.

[ic-racer]

How to do flip it without getting your hand/fingers into the field of view of the lens?

As Kiwi7475 posted, I'm planning on attaching a string. Perhaps the string could be looped on the hose, so pulling the air hose will trigger the fan to drop.

Based on another post on the forums here, I just ordered a box of 50 the 1/2 price Fomapan 8x10 film that Freestyle is selling. Planning on using the whole box with this lens.

[rayfor]

Refering to simulation, the exposure time on the edge should be 4.9 times to the center. Considering long exposure time, this ratio should be larger. Also, with simulation data, I was able to design a fan for single exposure with pure mathematics. Would anyone like to try this? Also I'd like to make few 200mm hypergon. This is the only hypergon I could not even find a picture of.

[Kiwi7475]

Refering to simulation, the exposure time on the edge should be 4.9 times to the center. Considering long exposure time, this ratio should be larger. Also, with simulation data, I was able to design a fan for single exposure with pure mathematics. Would anyone like to try this? Also I'd like to make few 200mm hypergon. This is the only hypergon I could not even find a picture of.

I’d be more than happy to test the new fan.

Also interested in the 200mm if you end up producing it.

[Corran]

Rayfor, in my opinion the next focal length of choice would be 150mm.

The 210mm XL is out there and available (if expensive!) for ULF use, but the 150mm should cover up to 16x20 and so would be more exotic IMO. For instance on my 12x20...and still of use for 11x14 or 14x18.

I would be interested in trying your other fan too.

Can't wait to get the 75mm.

[Corran]

PS! It doesn't work on my Wehman LOL. Bellows won't compress enough.

Attachment 244627

I've noticed the lever to drop the fan doesn't seem to work without the lens pitched forward slightly. I wonder if that's why many photos I've seen from Hypergon lenses seem to be slightly aimed down from level...

I think I can tie a very small piece of string to the fan and tug it down...carefully! to not disturb the camera.

[Kiwi7475]

PS! It doesn't work on my Wehman LOL. Bellows won't compress enough.

Attachment 244627

I've noticed the lever to drop the fan doesn't seem to work without the lens pitched forward slightly. I wonder if that's why many photos I've seen from Hypergon lenses seem to be slightly aimed down from level...

I think I can tie a very small piece of string to the fan and tug it down...carefully! to not disturb the camera.

Yep, sometimes it doesn’t just go down if it’s not pitched down slightly… I’m thinking maybe using a really thin synthetic string (like a fishing line of 0.01”) attached to the lower bar of the star (the one that goes vertical once you mount the lens board on the camera) to pull it down.

(I think the original Hypergons had another bulb to get air to push on the star and move it out of the way, which is quite clever… maybe this was not in the 75mm if this is an exact replica?)

Also note how the star has a notch at the top for the lever (which ends like a flat screwdriver) to fit in. It’s not supposed to go all the way in (meaning if you keep the lens board flat and then grab the star with the lever, the end of the lever holds it past the notch, which is neither very stable nor makes the star leveled wrt the optics).

And yeah, compressing typical bellows to 7.5 cm is not easy!

[Corran]

I was also thinking about that area, maybe drilling a small hole in that lower bar for the string. Good idea on the fishing line, I have some very thin stuff here.

I'm going to try building a 75mm box camera with stuff I have here. I think if I can use the rear GG panel and bail back from my Wehman and use a 12x12 frame as a box along with some plywood sheets I should be able to make something, but I'm really not a wood worker. My mom is though and I'm visiting her for Christmas...

[Greg]

I once was in contact with a photographer (in possibly Vietnam?) who either he did or he had Chamonix modify one of their ULF Chamonix cameras to use with his Hypergon. Unfortunately lost his Email. If he is a member of this FORUM, I would love to know more. If not, Hugo could you chime in?