Comment by hristov | Hacker News Reader

Comment by hristov | Hacker News Reader

Parent Full thread

Focusing with point and shoots should not be a problem. They all have a huge depth of field due to their small sensors, so you have to try really hard to put something out of focus. Smudged pictures on point and shoots are usually not a result of lack of focus, but something else (e.g. shaky camera).

Even with DSLRs you usually only need one focus point. You can focus at the center and re-frame. It is very simple to do, and is much simpler than choosing a focus point (and much safer than trusting the camera to automatically choose a focus point for you). Multiple focus points can be very useful in certain rare circumstances: when shooting something really fast off of center without being able to pre-focus or when your camera is bolted down on a stand. Even then I cannot possibly imagine one anyone would need 51 points. This is obvious feature creep.

But yeah, I am really not sure who the intended market for this camera is. Focusing is just not a pain point, in my opinion. This camera could be used by artists and professional photographers to play around with the depth of field to get a great artistic shot, without making their subjects wait. But with the micro-lens design, will it have enough image quality for professionals? I guess we will see.

Focusing with the center AF sensor only and recomposing will generally put the plane of focus behind the intended subject (assuming the lens does not have an extraordinary degree of field curvature). The geometry is easy to see if you remember that your focus distance is the distance from the sensor/film plane to the subject, not the distance from the lens to the subject. The problem is more noticeable with a wider lens, a larger aperture setting and a closer subject, but it's always there. That's why Hasselblad (who only offer one AF point in the H4D camera system) has incorporated positional sensors and focus correction in their latest models.

If your camera offers the option, choose a focusing composition that will put your subject as close as possible to its final position in the picture and use the focus point closest to that position.

You cannot re-frame when shooting moving subjects - kids playing, sports, birds, cars, motorcycles, boats - there's all kinds of instances in which your subject doesn't stand still and even has unpredictable moving patterns, so keeping your subject in the center of the frame and/or re-framing is in many instances not feasible.

Nikon DSLRs have this 3D tracking feature in which you select an object to keep in focus and it refocuses based on its movement inside the frame when it hits the focus points. And when the subject exists the frame and re-enters, auto-focus comes back. 51 focus points may seem like feature creep, but as I said, it's freaking awesome when shooting moving targets like birds.

Even for subjects that are still, like for portraits, you have a lot more freedom for composition as you just select the person's eyes and then you can move around while the eyes are kept in focus.

Of course, you can do a good job with a single focus point, but professionals and amateurs need predictable results, because good moments for taking photos are rare and you don't want to screw up because your camera wasn't properly focused.

That's why I can see partly the utility of this technology here, but on the other hand I can see serious problems with it too, the biggest one being that for most people quantity of photos trumps quality. Another problem that I can see is the one I mentioned above; precise and predictable focus is not that much of a problem with modern cameras. And yet another: mega-pixels and quality of optics count a lot. Well, maybe once passed a certain threshold, the there's less ROI from a higher MP, but still, under 6 MP a camera is only usable for publishing on Facebook.

My consumer DLSR has 4 FPS and I don't worry about focus as I just continuously shoot like 20-30 pictures in a row to make sure one of them is good, and usually one of them is.

> under 6MP a camera is only usable for publishing on Facebook.

2560x1600 pixels is 4.1MP. At 1:1 that will completely fill the most monstrous computer monitors one can get for under about $10k. At 300 pixels per linear inch (a very reasonable resolution for photos; about the same as the iPhone 4 "retina" display) it will give you a picture with 10" diagonal.

Unless you're making posters or big prints for photographic competitions or something, even at 4MP raw pixel count is not going to be your problem. It's completely untrue that below 6MP your pictures will be useless for anything beyond Facebook.

(Of course pixel count starts to matter more if, e.g., you're taking pictures of distant birds or distant celebrities with a not-especially-long lens and you need to crop heavily. Most photographers, most of the time, are not doing that.)

Don't forget about pixel quality (it's understandable because the industry has been encouraging it for years).

A 6MP sensor would produce a fantastic 10"-diagonal print if its pixels weren't affected by noise and it was combined with a high quality lens. Unfortunately sensors of that resolution are typically small (=noisy pixels) and placed in point-and-shoot cameras (=cramped, low-quality optics).

Or you could buy a top of the range pro DSLR from 5years ago with this resolution, with fantastic lenses and bullet proof build for the price of a modern entry level camera

I find the higher mega-pixel really helps on cropping. Especially when photographic wildlife like a dragonfly its nice to be able to crop a photo to just focus on that while still maintaining resolution. For me 10MP minimum is for this purpose rather than large prints. 2c this looks like a really cool technology, I would love to see it built into phones.

Reply on news.ycombinator.com