Sunday, September 14, 2014

Fuji S1 – Review Part 19 – Finding the best focal length for shooting macro …

Apparently, the HS50EXR has a funky magnification curve such that maximum magnification is somewhere in the middle of the focal range.

Well, I’ll cut to the chase and clearly state that the S1 does not have any of that funkiness. The maximum magnification in non-macro and macro modes appears at 215mm, or 1000mm EFL. With macro on you get slightly better magnification. That looks like this:

Now, the sensor on this camera is a wee 6.17mm across, so this magnificent 74mm width means that we’re getting a paltry 1:11.99x. Super zooms like the Nikon 18-200VR typically manage 1:3, or 1/3rd life-sized. But … since the sensor is so small, the actual physical object (e.g. a bee) still fits quite nicely in the frame. A large bee will obvioualy take up more than 1/4 the width of this frame, so the magnification remains very useful for hunting small creatures, as I have found.

The magnification gets worse very fast without macro enabled, but it still gets worse immediately with macro enabled, so walking about and shooting flowers and insects will inevitably be done at full zoom with the S1.

So why does it not have the best magnification at full wide, as cameras used to do? I’;m not sure about that, but it is definitely not able to focus close enough to get the same magnification. And we are getting close enough now that there is a definite problem getting light around the lens. For example …

That image is awful because of the light problem. It is also showing 1:14.1 magnification, quite a bit worse than 215mm. But we can actually get quite a lot more magnification be engaging Super Macro. Unfortunately, it is so close to the subject that all the light is blocked out. I consider this mode useless under all but the most unlikely circumstances – a back lit transparent subject, basically.

Here’s what that looks like:

And here is the subject to front element distance:

Note also that setting super macro automatically zooms out all the way to 4.3mm.

As a control, I mounted the Sigma 105mm 2.8 Macro onto the G6 and set it to minimum focus distance, which is 1:1 macro. Allegedly. And how did it do? Well …

That 98% life-sized, so effectively 1:1 …


A note on methodology:

I mounted a set of macro rails on my sturdiest tripod and attached the S1 to it. I pushed the camera forward slightly at each focal length until it would not focus. I then backed it up and started moving forward with the rail until if failed. I then backed off a bit and tried until it locked in. I moved forward in ever-smaller increments until I found the sweet spot.

Note: This is a pain in the ass, period. Fuji does not immediate focus when you back out from a failure. You have to go back quite a bit until it locks again, and then move forward in tiny increments. If you make a mistake, you have to repeat the process. No on in their right mind would do that on a regular basis, so one will rarely get the absolute maximum magnification. But you can get close enough for practical purposes …


And finally, the raw data. First the table of focal lengths plotted against magnification. It is expressed and interpreted many ways …

Things become clearer when graphed …

As you can see, you get really close to maximum magnification at 59mm (3x tele) … but 1000mm still wins. Of course, if you want to shoot closer, this might be more comfortable. But the backgrounds won’t be quite as nice, so bear that in mind …