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Comment by jcattle

7 hours ago

I mean, your prompt is basically this skit: https://www.youtube.com/watch?v=BKorP55Aqvg ("The Expert" 7 red lines: all strictly perpendicular, some with green ink some with transparent ink)

I couldn't imagine the image you were describing. I've listed some of the red lines with green ink I've noticed in your prompt:

Macro Close Up - Sharp throughout

Focus on tiny gear - But also on tweezers, old watchmakers hand, water drop?

Work on the mechanism of the watch (on the back of the watch) - but show the curved glass of the watch face which is on the front

This is the biggest. Even if the mechanism is accessible from the front, you'd have to remove the glass to get to it. It just doesn't make sense and that reflects in the images you get generated. There's all the elements, but they will never make sense because the prompt doesn't make sense.

The last point (reflection by front glass versus mechanism access so no front glass) is the only issue I see with it. Other than that I can easily visualize an image that satisfies the prompt. I think that the general idea is a good one because it's satisfable while having multiple competing requirements that impose geometric constraints on the scene without providing an immediate solution to said constraints as well as requiring multiple independent features (caustics, reflections, fluid dynamics, refraction, directional lighting) that are quite complicated to get right.

To illustrate that there aren't any contradictions (other than the final bit about the reflection in the glass). Consider a macro shot showing partial hands, partial tweezers, and pocket watch internals. That's much is certainly doable. Now imagine the partial left hand holding a half submerged pocket watch, fingertips of right hand holding front half of tweezers that are clasping a tiny gear, positioned above the work piece with the drop of water falling directly below. Capture the watchmaker's perspective. I could sketch that so an image model capable of 3D reasoning should have no trouble.

It's precisely the sort of scene you'd use to test a raytracer. One thing I can immediately think to add is nested dielectrics. Perhaps small transparent glass beads sitting at the bottom of the dish of water with the edge of the pocket watch resting on them, make the dish transparent glass, and place the camera level with the top of the dish facing forward?

https://blog.yiningkarlli.com/2019/05/nested-dielectrics.htm...

A second thing I can think to add is a flame. Perhaps place a tealight candle on the far side of the dish, the flame visible through (and distorted by) the water and glass beads?

  • Without the last point with the watch glass it is also easier to imagine for me. Still, you'd have to be selective.

    Do you want it to actually look like macro photography (neither of the generated images do)? Then you can't have it sharp throughout and you won't be able to show the (sharp) watchmakers face in a reflection because it would be on a different focal plane.

    Dropping the macro requirement, you can show a lot more. You can show that the watchmaker is actually old, you can show the reflection, etc.

    Something has to give in the prompt, on multiple of the requirements. The generated images are dropping the macro requirement and are inventing some interesting hinging watch glass contraptions to make sense of it.

    • Yeah, fair enough. I figure "macro" sees sufficiently loose use that a model should be able to make sense of it but to get the prompt into perfect shape that ought to be replaced with something like "a closeup showing X, Y, Z in perfect focus". Still the only real problem I see is the aforementioned contradiction regarding the front glass. Short of that single detail an artist could easily satisfy the description as written to well within reason.

Yeah I dunno bud, I have a degree in film and three Emmy awards for technical production (an expert), I could shoot that prompt (unlike the so called "expert" in the skit). Canon EF 100mm Macro USM at f32 should be able to produce that, focus doesn't need to imply aperture, and a quick google search shows me there are loads of front gear pocket watches available. Also it produced something very clearly not shot with a 100mm anyway, as the telephoto compression is wrong.

  • Yeah I dunno bud, I've watched a few watch repair videos on youtube and have seen macro photography which other people did.

    Sure there are pocket watches where the movement is visible from the front (you'd still likely service them from the back, but alas). Even if you'd do service from the front where the glass is, you'd still have to remove it to drop in a gear.

    Anyway, I think that we aren't really talking about the same thing. I'm nitpicking your prompt while you constructed it to mostly see the performance of the model in novel situations and difficult lighting and refraction environments. And that's fair.

    How satisfied are you with the generated image results? What would you do different when shooting this proposed scene yourself?

    • Reasonable people can disagree - I think you made some good points, I've been sitting for the last 20 minutes wondering where the DoF at 32 on a 100 runs out, maybe you're right I'm not 100% sure.

      The prompt I did mostly to see how it does with the gears and the tweezers, and the perspective of the gears (do they.. I don't know the opposite word of distort, straighten?, but do they seem like they're actually round, could they work?) I think those are really hard things for AI, the glass distortion, reflections the DoF etc were just to see how it approached that, and like the other comment below said, I tried to pick something that that wasn't likely to be in training data, so it reasoned about it more.

      Nano was able to spit it out consistently, Images 2 really struggles, and has yet to complete one I was satisfied with, whereas with nano it nails it almost every time, the 2 images I showed originally are the first shot of the prompt with the models. (here are the 3 other gens from Images2: https://drive.google.com/drive/folders/1s8gik_x0B-xDZO6rOqoz...)

      How would I shoot it? I wouldn't, fixing a watch in water is a dumb idea. ;)