Depth of Field Adapter on Steroids

ProfHankD wrote:

JonesLongShot wrote:

Tons o Glass 0 Class wrote:

Hmm. I'd expect a slight "echo" of things from the thickness of the mirror glass. There are plenty of very thin cheap films, often sold for window privacy/UV blocking, that are one-way mirrors. However, a teleprompter is designed to be photographed through, so that's a very appropriate thing to try.

Oddly the projected image just seems to be absorbed by the black walls. I guess you could try reversing the mirror and put the focusing substrate on the wall facing the mirrorless camera. I just didn't try that. I just painted the entire interior black. Vanta Black would probably be perfect.

Vanta Black isn't a paint. Get some Black 2.0 or Black 3.0.

It was just the blackest thing I could think of.

I like the idea of the shift lens too. Just another way to solve the off axis problem. Probably a better solution than mine to be honest as my implementation does have light losses. However it is really easy to get an excellent on axis image and in a fairly compact assembly with a beam splitter.

The shift lens is an elegant solution... although arguably you can do the same just by pointing the camera straight at the image with an offset -- in other words, implementing the shift on the big lens rather than the little one. Of course, using the big one for the shift, you might have the off-axis artifacts of the big lens obviously decentered.

I looked at lab grade beam splitters and quickly decided they were not a good option. The prices prohibitive. Teleprompter glass is easy to get. I purchased samples that were 9 inches by 9 inches for like $12 each. I figured this was effectively a somewhat lofi type of project so lab grade beam splitters probably wouldn't make a huge difference.

High-end teleprompter glass should be very good. I haven't seen any as cheap as $12; I'm seeing more like $60.

I purchased samples from twowaymirrors.com. Looking back at my order I see they were 6x6 and not 9x9 and the actual price was $14.95 ($24.04 with shipping.) This is what I ordered.

6" x 6" (152.4x152.4mm) Teleprompter Mirror Sample - 1/8" (3mm) Thickness

twowaymirrors.com/product-samples

6x6 was large enough to experiment with.

The most important material is the focusing substrate as it defines the look and detail of the final image more than anything. I tried lots of different papers and things like white polystyrene and bead blasted aluminum. In the end I liked really fine paper the best. This part still needs lots of experimentation. The finer the surface structure, and the more reflective the material, the more it approaches an actual mirror and that completely destroys the whole thing.

Ordinary white paper was what I ended-up using in the FourSee TDCI Multi-Camera . The best image quality was actually using an Illford inkjet paper, except it was glossy enough to give some reflections.

One more variation of these photographing-the-focusing-screen type rigs is by using a tilt-shift lens to image the projection, like Zev Hoover did for his "large format video camera":

https://www.dpreview.com/articles/3423280809/how-i-built-a-large-format-8x10-video-camera

I think his project is fantastic.

Not bad, but pretty pricey with that shift lens...