Hacker News Reader

> Tilt-Shift lenses are great and I own one but ... just like many things in photography now-a-days, computation can do much of this.

No it can't. You can not reliably tilt the plane of focus, something that precisely the tilt-shift lens does.

> No, it's not perfect just like an iPhone doesn't take as a good a picture as a high-end Canon/Nikon/Sony.

iPhone actually does very middle of the road pictures. You can never beat a Canon/Nikon/Sony simply because you do not have the sensor size. I am not even going to try to bring metering discussion here.

> And even on a large screen (my 65" TV) they still look great at a glance.

Depends on the viewing distance. Put ink on paper, and then we will talk.

> Let me change the perspective live while I'm taking the picture. IIRC I found apps that do this but they want $10-$20 a month. Here's hoping Apple and Google add it to the default camera apps. This could be even better because given computational photography the phone can take 10-20 shots at 1000fps and then merge them for higher res in the areas where there's less censor pixels per arc angle.

No, you are wrong. When you are shifting, you actually move over the "sensor" in the focus circle, not merely do a cropping gizmo like apps do.

If you want to really understand why view cameras still whip ass and tilt shift lenses are relevant, try taking photograph of a tall building and see how the edges are not parallel and if you try to correct that in software, you will see distortions.

I'm sorry but for 90% of picture consumption today, i.e. on phones, the original commenter is right. iPhone photos are good enough to look at on your phone. I'd guess that something like 90% of photos today are a) viewed on a phone and b) looked at for less than three seconds each.

You don’t get a TS lens because you’re trying to make a discardable commodity image on a discardable commodity phone… yes, 90% of the images humanity takes aren’t worth viewing, much less keeping, but that doesn’t mean iPhones are “good enough” for images that are important, and in the coming decades we’ll really regret all of our visual legacy having been recorded with lossy compression through crap lenses on ludicrously small chips.

(context: high end tilt-shift lenses are used for architecture photos to make buildings and complexes look all square everywhere and not tapered skywards due to perspective effect. The stakes are higher and spending more effort than snapping and editing on an iPhone is justified)

You can’t do the ‘tilt’ part computationally (except by going all-in and computing a depth map), but simple perspective corrections do a good job of emulating ‘shift’. Shift is typically used for subjects at infinity (such as buildings) where small changes to the plane of focus are irrelevant.

Computational shift is a quick and dirty fix for a random picture with the – auspiciously, should I say – «misaligned» perspective that can be salvaged without the detriment to the composition.

Oftentimes that is not the case, though, and results in a crop anywhere between 25 and 40% completely ruining the composition.

Both have their merits, and I occasionally use the computational shift to fix the perspective in my phone camera snapshots with a varying degree of success, but if the circumstances are conducive, I will bring and use my full frame DSLR with the trusted manual TS-E 24mm lens. It is much more fun that way, too.

Tilt, however, is a completely different cattle of fish…

I know the author poo-poos on it, but I thought the miniature effect was cool and I'd buy a tilt-shift lens for my old medium-format camera solely for that purpose. I've never seen a phone pull off an effect like that, and even if it could, sometimes it's just more fun to do it the hard way.

It's very simple to create a similar effect in post.

For example blur the image where the blur radius is high at the top and bottom of the image and zero at the center.

Of course this does not take depth into account but simulated the effect well.

There are a lot of tutorials about this subject.

Without compositing images, or small aperture with artificial blur, computation can’t help you with the tilt effect like the one of the store sign reading Arche, can it? The geometry of that shot is interesting to me.

I like the compositing idea though. Could that get us 50 % of the effect with 5 % of the bulk and cost?