Thursday, June 14, 2012

Fuji X-S1 Review – Part 3 – The Mighty Saturn

So long as I can review cameras in summer, I will shoot Saturn as a very difficult test. I was impressed that the F770EXR was able to do a credible Saturn earlier this year, and I was totally shocked at how well the HS25 captured Saturn with its incredible zoom and despite shooting only JPEG.

So it was with great anticipation that I set up this evening on the best evening of them all with the moon nowhere in sight (it rises much later on) … this should have been a slam dunk.

But it wasn’t. There was this mush bursting out of the planet on every image. This bleeding looked a little nebulous and more or less ruined the outline of the planet. Of course, I salvaged the best image -- shot in high resolution by the way as there was no advantage to low resolution – by painting out the blob to create a reasonable facsimile of the planet.

So using the JPL simulator, I was able to determine what Saturn should look like:

Here’s what I got in RAF and then JPEG … (same image, both processed in Lightroom 4 and then CS5.

fuji x-s1  500iso  f/5.6  1/25  634mm efl (RAF)

Same image (JPEG)

And just to remind you what the HS25 did …

The image is more complete and the planet and rings are separated. It tool a lot of processing to get there, but I did not cheat and do local painting like I had to for the X-S1. So this isn’t just a win for the HS25 over the X-S1, it’s a bit of a thrashing.

I’m profoundly disappointed in this result. Hopefully, I can improve on it while I have the camera. I hope it isn’t somehow limited.


  1. Why magnify the image so much? Because it was just not very clear, so I felt that more magnification might allow us to see the rings and the separation from the planet a bit better. It didn’t really work out.
  2. I realized a moment ago that this weird aberration is exactly the sort of thing that might manifest with the drooping lens. What it does is destroy acuity, and that’s what this blog did. So I will attempt next time to use gaff tape to hold the lens in the middle when fully zoomed. Difficult, but it might work.

Here is a 1:1 and an 8:1 representation of Saturn at 1:1 and 8:1 on the sensor … note that they appear approximately the same size on the sensor because the HS25 has more optical magnification but the X-S1 has more digital magnification (12Mp instead of 8Mp as each was shot.)

x-s1_vs_hs25_bloom It is more than a little obvious that there is a spectacular bloom coming out of the left side of the planet. I noted this on every image I shot and it was the reason why I decided to shoot at L size instead of M. I needed more digital magnification to see what was going on.

I must say that this is pretty disappointing, especially since the much cheaper and JPEG-only HS25 does not suffer the same issue. But we already know that the X-S1 lens droops, so perhaps correcting that will mitigate the aberration. We shall see.