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Lens Blur in the new Google Camera app

googleresearch.blogspot.com

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Re: Lens Blur in the new Google Camera app

#71

Post by jwarren »

raldi wrote: post #60
jawns wrote: post #5

Regarding the technology (achieving shallow depth of field through an algorithm), not Google's specific implementation ... Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR). You can simulate it in Photoshop, but generally it takes a lot of work and the results aren't great. The "sh…

> Up until now, a decently shallow depth of field was pretty much only achievable in DSLR cameras (and compacts with sufficiently large sensor sizes, which typically cost as much as a DSLR In 2008, I had no trouble taking shallow-depth-of-field photos with a dirt-cheap Canon A570 pocket camera. For example: https://farm3.staticflickr.com/2069/2076688334_aeae12583b_b....

Some things worth noting:

Depth of field increases as the focus point moves deeper into the frame.

Depth of field decreases as your lens length increases.

Depth of field decreases as your sensor size increases.

The A570 will have a relatively large sensor compared to a mobile phone, and your subject was very close to the lens. These things considered, the depth of field isn't impressively shallow. Reducing the sensor size to that of a phone and moving the subject further away will make shallow depth of field impossible. The portrait examples on that Google page are exactly the sort of thing that wouldn't have been possible previously.

Re: Lens Blur in the new Google Camera app

#72

Post by gomox »

reustle wrote: post #67
grecy wrote: post #12

We had an interesting discussion about this a few nights ago at a Photojournalism talk. In that field, digital edits are seriously banned, to the point multiple very well known photo journalists have been fired for one little use of the clone tool [1] and other minor edits. It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not ve…

> It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not very representative of what my eyes saw I beg to differ. Pictures with a shallow depth of field feel more real because that is how the eyes work naturally. Hold up your hand at full arms length, and focus on it with your eyes. Everything else around it is blurred.

An f/1.8 lens on a DSLR has much shallower depth of field than your actual eyes though.

Re: Lens Blur in the new Google Camera app

#73

Post by seba_dos1 »

Looks exactly like "shallow" mode of BlessN900 app for Nokia N900 from few years ago.

It's funny to see how most of the "innovations" in mobile world presented today either by Apple or Google was already implemented on open or semi-open platforms like Openmoko or Maemo few years before. Most of them only as experiments, granted, but still shows what the community is capable of on its own when not putting unnecessary restrictions on it.

Re: Lens Blur in the new Google Camera app

#74

Post by avaku »

sp332 wrote: post #62
avaku wrote: post #58

Earlier quoted context omitted.

It does simulate the lens, it says so in the article

Oh... well it doesn't do a very good job. The last example has her hair blurred where it should be sharp. That's not very lens-like.

Yeah, in the first example too (hair at the bottom). But it's still much better than Gaussian blur...

Re: Lens Blur in the new Google Camera app

#75

Post by alanh »

reustle wrote: post #67
grecy wrote: post #12

We had an interesting discussion about this a few nights ago at a Photojournalism talk. In that field, digital edits are seriously banned, to the point multiple very well known photo journalists have been fired for one little use of the clone tool [1] and other minor edits. It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not ve…

> It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not very representative of what my eyes saw I beg to differ. Pictures with a shallow depth of field feel more real because that is how the eyes work naturally. Hold up your hand at full arms length, and focus on it with your eyes. Everything else around it is blurred.

You’re both right, to some degree. While you are correct that the eyes focus at a certain depth, much like a camera, the difference is that we can chose to focus at any depth (assuming good eyesight). This is not true of a photograph if it has no depth. (It’s also true that, if the photograph has both fore and background in focus, edges may be harder to pick out and depth harder to discern, even though we would have no trouble with our own eyes. That’s the basis of much trick photography, after all!)

All photos are unnatural. To quote the artist (and, dare I say, photographer) David Hockney: “I mean, photography is all right if you don’t mind looking at the world from the point of view of a paralyzed cyclops—for a split second.”

At risk of this becoming too long-winded, allow me to point out another “normal” variable of photography that is wholly unnatural (beyond the issue of focus and the fact that one moment is extended to infinity): Shutter speeds faster than 1/150s or slower than 0.5s. Our own eyes will never see the individual blade of a helicopter so clearly as a simple iPhone camera will when shot against a bright sky. Nor will naked eye see a waterfall as a blurry, peaceful average the way a long exposure portrays it.

Re: Lens Blur in the new Google Camera app

#76

Post by georgemcbay »

grecy wrote: post #12

We had an interesting discussion about this a few nights ago at a Photojournalism talk. In that field, digital edits are seriously banned, to the point multiple very well known photo journalists have been fired for one little use of the clone tool [1] and other minor edits. It's interesting to think I can throw an f/1.8 lens on my DSLR and take a very shallow depth of field photo, which is OK, even though it's not ve…

On a slightly related tangent, every time I see someone post a "#nofilter" photo on facebook I have to bite my tongue to stop from asking them how their camera managed to separate the RGB channels without a Bayer (or similar, eg Foveon) filter.

I mean, I sort of get what they are saying and I hate the overuse of Instagram filters probably much more than the next guy, but the odd relevance people place towards getting an image "directly out of the camera" is bizarre considering the incredible number of decisions (sometimes correctly, often not) the average digital camera has made for you in getting the measured light into a jpeg.

Personally I much prefer to shoot in RAW and then post-process because cameras, as amazing as they are in some ways, are still incredibly dumb when it comes to context and intent and I'm going to do a better job at getting the white balance, dynamic range, contrast, etc right (for how the shot was intended) than the camera is.

Re: Lens Blur in the new Google Camera app

#77

Post by seba_dos1 »

mcescalante wrote: post #20

I may be wrong because I don't know much about image based algorithms, but this seems to be a pretty successful new approach to achieving this effect. Are there any other existing "lens blur" or depth of field tricks that phone makers or apps are using? I'd love to see their code open sourced.

Well, the only "new approach" I can see here is letting the user decide which part of image should be sharp. BlessN900 camera app for Nokia N900 was doing exactly what this new app does few years ago, but it was choosing the focus point automatically.
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