Meandering discussion about the utility of aerial lenses

[PolarBear1973]

This is a great picture in itself. Looks like you just buried a good friend and that's his hat! Impressive!

Asher

Thanks! Here's another shot I took yesterday with the same camera:



12 second exposure at f/32.

[Jay Decker]

Water Trough Hydrant

8x10 Kodak 2D
Air Ministry 14" f5.6 TTH Cooke Aviar - Wide Open
8x10 Efke 25
Bickleton, WA

[Asher Kelman]

Water Trough Hydrant

8x10 Kodak 2D
Air Ministry 14" f5.6 TTH Cooke Aviar - Wide Open
8x10 Efke 25
Bickleton, WA

Well this is marvelous, Jay! I'd have thought Jim Galli took this picture, but there's no swirl! I wonder how this would be on a portrait. The DOF is perfect for the faucet.

Stopped down, for a building, I wonder what that could give.

Was there any possibility of movements had you wished?

Asher

[Dan Fromm]

Per the VM, used on 5"x5". Aviars cover a little more than their focal lengths sp the 14"/5.6 should be good for 8x10. Uncoated, flary, in my tests sharpest wide open.

Asher, do your own homework. Get a copy of the VM and consult it before using Google. Use Google before asking questions.

[Jay Decker]

Well this is marvelous, Jay! I'd have thought Jim Galli took this picture, but there's no swirl! I wonder how this would be on a portrait. The DOF is perfect for the faucet.

Thanks Asher. This lens is a Jim Galli hand me down. You can see the images that Jim took with this lens earlier in this thread here. I purchased the lens from Jim for two aesthetic characteristics, out of focus rendering and internal flare (yes, I intentionally wanted a lens with flare). More specifically, I intend to shoot some back lit portraits with this lens to take advantage of the OOF rendering and flare.

Stopped down, for a building, I wonder what that could give.

Was there any possibility of movements had you wished?

The image below has a development issue, but was taken with the same lens stopped down to f/11. And, it had quite a bit of vertical rise (the perimeter of the image is vignetted in image editing software). It was pretty windy, and I think there is a little motion blur in the image.

[Asher Kelman]

Thanks Asher. This lens is a Jim Galli hand me down. You can see the images that Jim took with this lens earlier in this thread here. I purchased the lens from Jim for two aesthetic characteristics, out of focus rendering and internal flare (yes, I intentionally wanted a lens with flare). More specifically, I intend to shoot some back lit portraits with this lens to take advantage of the OOF rendering and flare.



The image below has a development issue, but was taken with the same lens stopped down to f/11. And, it had quite a bit of vertical rise (the perimeter of the image is vignetted in image editing software). It was pretty windy, and I think there is a little motion blur in the image.

Jay,

I'm so glad you have that lens. I considered it too. I am also taken with the lenses that work well for art, opened up. What's important, more than descriptions, is actual experience and these pictures. Both the vade mecum and original descriptions are informative, but nothing beats the actual delivered photograph. You'll have a lot of fun with this!

Thanks for sharing.

Asher

[genotypewriter]

This camera, with a vacuum back would then not appear too far fetched!

Asher

At that price, hope the quality is different from what the lens name suggests ;)

However, I just need a lens for 8x10 or 5x7, whichever is more $$ and weight practical to end up with 16ft, (~ 5 meters high), and detail at 25cm.

So it's a matter of cost and whats' available in a setup that can be moved in a station wagon and set up 100 meters from the vehicle.

The lens has to be available and have a straightforward engineering path using available film, color and B&W.

The larger the film, up to 11x14, the easier it is to get the details from it by scanning. I have a Topaz II which I'm in the process of trying to bring alive.

It seems I need 24 x magnification from 8x10 and that would mean 24 x4 lp/mm= 100 lp/mm - 160 lp/mm

Thanks for your help.

Asher

Pardon me if someone has already pointed this out but this intrigues me to do some numbers...

If you want 300dpi or around 12 lines/mm on a 5 meter (or 5000mm) reproduction, you're looking at a:

12 * 5000 = 60000 line image (say on the long side).

To get 60000 lines from a 8x10" sheet of film (assuming you can get the whole 10" or 254mm), you need a lens that can resolve:

60000 / 254 = ~236 lines per mm.

Now let's calculate the minimum f number you need to get that resolution without being limited the airy disk size:

First for blue (say 450nm) light:
(1/236) / (1.22 * 0.00045) = f/7.7

Then for red (say 680nm) light:
(1/236) / (1.22 * 0.00068) = f/5.1

So you need to find yourself a 8x10 lens that produces 236 lines per mm across the frame at apertures not smaller than f/5-8... stopping the lens down further means you can't produce that many lines. If it's a 5x7 the f numbers would need to be even smaller.

It also makes me wonder how much you're going to have in focus across the frame on a 8x10 at f/5.1 because of the DOF. You'll have to shoot things that are very very far away.

You must also look in to how film impacts all these. Just to put things in to perspective, you're talking about getting 48 megapixels worth from a 35mm slide/neg of film. Which we all know is way past what we can comfortably get out of slide film. In fact, 24MP from a 35mm slide is like the practical limit even with drum scanning. Resolution capabilities aside, don't forget that chunky film grain either!

Just some food for thought :)

GTW

[Asher Kelman]

Thanks TW for your helpful look at the challenge. I decided it's simpler for me to use the Camera Obscura I'm also building, as I can use any film size and test any lens and no film holders are needed, just a vacuum board. From this I'll determine what the lenses can do and then I'll get a mobile version of the right size LF/ULF camera for making giant enlargements that can be viewed up close for detail.

I've now a good series of lenses and after these are mounted on lens boards I'll start testing. I'm writing my progress here. I'm starting with Cibachrome, (ie Ilfochrome) paper at 3 ISO, but at the same time, will also test faster film to research this different project for giant enlargements.

Asher

[Superzeiss]

genotypewriter mixed up " lines per mm " and " line PAIRS per mm ".

Imagine 250 black lines on one mm, your millimeter will be pretty black . . .

That is why there has to follow one white line on one black line.

In this case, you have 250 black lines, and 250 white lines, and the width of one

line is 1/500 of a millimeter. In other words : 500 dots per mm, exmakes 12,700 dpi.

So divide GTW's math by 2 . . . .

The sweet F-stop for Ashers project ( to print 5000mm at 300dpi from 250mm negative at ) is approx. f- 12,5 .

Best wishes, Thomas

[Jay Decker]

Sharon

8x10 Kodak 2D
Air Ministry 14" f5.6 TTH Cooke Aviar - Wide Open
8x10 Efke 25 in 510-Pyro
Kennewick, WA