Saturday, April 13, 2013

HS50EXR – Review Part 15 – Shooting in Burst Mode is Mandatory

The HS50EXR has a massively long focal range. As much as many telescopes, as I clearly showed in part 8 of this series on astrophotography. And this camera also has brand new technology for phase detect auto focus. And something I am noticing as I go along is that the PDAF can be deadly fast and mostly accurate, but that it also misfires a lot. So much so that I have taken to shooting the HS50 exclusively in burst mode.

The reason is pretty simple. As we’ve experienced in our dSLRs, shooting a moving subject like a bird is something that often requires quick reflexes, where you see the animal, point at it and immediately start shooting. Even if it has paused, you know that won’t last for more than a second or two before it again moves.

So you rarely get a chance to point, compose, half press, check focus, half press again, and so on. Instead, what you do is blast off a set of images in a burst. And you rely on PDAF (or contrast detect auto focus – CDAF – in lower light) to deal with the changing circumstances and attempt to refine the focus between shots.

And so I found an absolutely perfect example to show you why you might want to do this. But before I show you the actual crops, let me who you what this looks like in Lightroom.


Here you can see that I have the images recorded in bursts in the film strip. The ones that are greyed out have been rejected and will later be deleted en masse. The selected images are the JPEGs that I sent to CS5 for creation of the crops image at full size. Photoshop remains a far better editor for those tricks than Lightroom.

What I did was to look at the JPEG images side by side using Lightroom’s compare view:


This is only available in the Library module, but it is more efficient to spend more time there anyway. So I select the first and second JPEGs in the series (first and third actual images) and it brings then up together. You also have to click 1:1 in the magnification panel at the top left so that you can see the sharpness of each. It is absolutely clear here that the later image in the burst is better.


I then clicked x on each of the JPEG and RAF files for 468 and moved on.

By the end, I realized that the burst got sharper as I went a long. The fourth image is tack sharp while the first is blurred. Which is why my tests try to eliminate this sharpness issue by shooting from tripod or shooting in bursts.

You really need to open this file to its full size to see how blindingly obvious this effect can be …

Note that they all look nice at the default display size, but even so you can clearly see the difference between the first and last images. That’s what I look for when I look at web sized images and I know when someone has been lazy. The plethora of embarrassingly bad tests of this camera on the forums shows me that few people have really tested it to see how the new AF acts. The answer is that it is more like PDAF in bright sunshine, with all the risks associated. And most are still shooting singles and then drawing wild conclusions from the results …

It is what it is … but I have to recommend that people consider this camera as a burst shooter, like they would with a dSLR if they know what is good for them. I have always shot multiples … even when I am not in burst mode, I am constantly shooting until the subject leaves. I have always found a surprising differences in sharpness from shot to shot …