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Comment by dylan604 | Hacker News Reader

other than for the lulz of "i shot photos with a video camera", this would have been so much easier with a mirrorless or DSLR. why record 160 frames to just export 1 frame. also easier to get >6K images as well.

sometimes, the "just because" really just makes me shake my head. I love the 3D printing of an adapater and playing with lenses in ways never envisioned by the vendors. after going through all of that hassle, to just tack on the hassle of exporting stills from video sequences is just odd.

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Focus stacking is indeed done with a DSLR most of the time. You cannot get nearly enough DOF at this scale with any kind of lens.

The author can do it from video because he has a 6K camera, and that is actually way easier compared to manually taking 160 separate shots + changing focus for each of them (you need specialized hardware for that, most cameras will give you a dozen shots at most due to coarse focus increments).

How do you figure? You take a single image, then move the camera or adjust focus, lather, rinse, repeat. In video, you do the same thing, except now you have to process each video clip to get export the single frame.

Oh, now I see why you’d think that. That would be insane.

No, you record a single video while moving focus and export each frame - that’s what makes it easier.

> The camera itself is mounted on an old edelkrone slider with a motion module. I record short 4K ProRes422HQ clips and use them for focus stacking directly in helicon focus. For this fly I used an average of 160 frames [from one clip]

Did you read the article?

"I record short 4K ProRes422HQ clips and use them for focus stacking directly in helicon focus. For this fly I used an average of 160 frames."

Clearly, he recorded multiple clips, and then exported individual frames from individual clips.

After all of that, he didn't even record in RAW.

Why the aggressiveness? If you want to believe that, be my guest.

This is a film production company, they most certainly have a stack of DSLRs they could use it it was that much more convenient, and with much better resolution. Not sure why you’d assume stupidity.

The software supports importing videos directly: https://m.facebook.com/heliconsoft/photos/new-version-of-hel...

As for RAW, unless you need that bit of extra dynamic range, it makes no difference (they don’t here, as it’s a studio shot with fully controlled lighting), ProRes422 is enough for 10-bit HDR even.

He says he records short clips and uses 160 frames from them. I don't see why you'd choose to read it as "recorded one video per depth".

And sure, it's not raw, but ProRes422HQ is pretty damn good, being both high pixel depth and very high bitrate.

This has to be the method. It makes the most sense given the strengths of a 6K video camera. Record lots of frames and use a dolly to take focus slices of the subject.

"Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that.""

https://news.ycombinator.com/newsguidelines.html

Also, can you please make your criticisms thoughtfully rather than as shallow dismissals or snark? Your comments in this thread are rather on the wrong side of the line, starting with https://news.ycombinator.com/item?id=26427684. You obviously know a lot about this topic, which is great, but the thing to do with that knowledge is share some of it, so the rest of us can learn, and leave out the putdown aspect.

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...

Processing 160 (or more, many many more) RAW files is much more of a pain in the neck than just taking the time to get everything right in camera and dealing with the jpegs.

Eh, my computer can deal with a RAW file in less than a second on one core, wouldn't be that big a deal.

Plus, a lot of RAW files are TIFF, so I'm sure GPU-accelerated stacking is in reach.

As someone with extensive experience in doing what you're describing with a DSLR, the video option sounds like a wonderful shortcut and I've wondered if it was possible to do it with my current equipment.

I've never done macro photography before, so this might be a silly question - but could you really get shots like this from a single DSLR image? Most macro photos I see have some part of the image in razor sharp focus, then a strong bokeh effect for the rest.

Not from a single image. The reason for the set up is to obtain many images at different focal distances. That can be done by either moving the camera (of any kind) or by changing the focus for each image.

Typically, it is not done by adjusting focus, and uses a sliding rig to change the position of the focal plane. For most camera lenses, the precision of the focus ring mechanism is too dodgy to precisely change the focus. With the slider, the focus ring is left alone, and the precision of the slider is use to bring the next "layer" into focus. The author even commented on the slider he used was not as precise due to it being belt driven and that switching to a lead screw system would have provided more accuracy.

OK. I have no first hand experience, but I saw that Helicon makes a product which incrementally adjusts a camera's focuser.

https://www.heliconsoft.com/heliconsoft-products/helicon-fb-...

Communicating directly with the lens' focus motors does sound more appealing and more compact than a sliding rig. However, "Helicon FB Tube automatically shifts the focus by one step with each shot thus producing a stack of images of unlimited length that can be rendered into a fully-focused image." That would mean that it is waiting for a shutter release type of signal from the camera body which would not be useful in shooting video as the original article's workflow.

Macro photography in my limited experience is as much about technique as equipment. No matter the camera, with that level of magnification you have to stack the images to get that much of the subject in focus. You can increase the depth of focus using the Scheimpflug principle and a smaller aperture, but there are real physical limits to how much. Decreasing the diameter of the aperture is limited by diffraction -- the image becomes less sharp even if more is in focus.

No. That's the point of focus stacking. However, using a still camera, you eliminate a lot of the work that was added because this was video.

you can use the same software this guy was using, and take multiple photos and stack them https://www.heliconsoft.com

the comment you're replying to was pointing out that using a camcorder and extracting stills from the video is a PITA, and it would be more straightforward to use a DSLR that can simply take stills. and they're right, but if the blackmagic was all this fellow had... well, it clearly worked well and a DSLR or mirrorless would've cost a few hundred dollars more.

since he was using a 3D printed adapter instead of buying one for $10, i can only assume he blew his entire budget on the blackmagic hardware.

The actual article said he didn't want to wait for 4 weeks while something shipped from China, so he 3D printed. Nothing implied not being able to afford a $10 part.

I would also stipulate that someone with a BMD 6K camera has other cameras as well. The BMD is typically the upgraded to vs started with type of camera. Sure, edge cases and what not

> Nothing implied not being able to afford a $10 part.

take a pill. it was a joke about the price about the blackmagic hardware.

> I would also stipulate that someone with a BMD 6K camera has other cameras as well.

no kidding.

According to a web page I found from 5-minute googling[1]:

  Depth of Field[mm] = (2 * u^2 * N * c )/ f^2

where:

u = distance to object[mm], N = f number(focal length divided by effective aperture diameter), c = diameter of acceptable circle of confusion[mm], f = focal length[mm]

Assume Sony A7M4 with Milvus 2/100: let u, N, c, f = (160mm, f/22, 4um, 100mm): DoF = 0.396mm ~ 1/3rd of a penny thick

The answer is no, not possible without focus stacking. But focus stacking is a SLR technique anyway, so the part that he's flexing his fancy camera a bit is true.

1: https://damienfournier.co/dof-the-simplified-formula-to-unde...

I think the flex here is photographic quality images from a video camera. 6000 pixels across is a higher resolution than the top digital cameras from a few years ago. Combine that with an easy way to extract hundreds of frames which can be stacked and you have a relatively simple way to create these deep macro photos. Similar techniques (e.g. lucky imaging) have been used for years by astro-photographers even in the days of 320x240 webcams.

It’s a mirrorless with 24MP APS-C sensor. Top mirrorless from a decade ago already had 24MP APS-C sensors. Top smartphone from a decade ago had better resolution(41MP).

I’m not saying the camera can’t be impressive, I’m saying you’re vomiting marketing script.

I'm not doing anyone's vomiting for them. I'm not in the target market here. There's no way I'm dropping $2000 on a camera that shoots only video.

As far as marketing goes, 41MP of noisy pixels from a 1/1.2" 2012-vintage sensor is not comparable to 24MP from today's APS-C sensors. Here's an image sample linked from a DPReview article from 2013 to get my point across.

https://www.dpreview.com/files/p/articles/7739037780/nokia-l...

From this article: https://www.dpreview.com/news/7739037780/nokia-image-samples...

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