Saturday, January 8, 2011

Fujifilm X100 – Image simulations …

The Fujifilm X100 has taken the Fuji forums by storm … well, it has taken a few people by storm and left the rest wondering. It is a very nice looking, retro styled camera with a fixed lens at 35mm effective (23mm objective) and a pretty snazzy viewfinder with digital overlay. Kind of like a heads up display that fighter pilots enjoy …

There is no real question that the CMOS APS-C (no … no EXR sensor) is going to be pretty nice. It should be clean as a whistle at 800 and have only light grain at 1600, if any at all. So I doubt that we should be wondering too much about that. We also know that people who were raised on fixed lens cameras and those who have already gravitated that way are going to love this thing.

But what about the rest of us? What kind of bokeh can we expect at such a short focal length? Even at f/2, this is still just 35mm … some consider that slightly wide. And how much fun can you have with one focal length?

Well, each of these is pretty easy to test. The first one does require an APS-C camera with an f/2 lens at 35mm. That’s a pretty rare commodity, although one could purchase an older manual focus lens for Nikon and get it that way. A but much for an experiment though. I have two lenses and a body that fits the bill perfectly … the D700 is full frame, so all I need to perfectly replicate the field of view and bokeh is a lens that can shoot at 35mm and f/2.8. Why 2.8? Because the APS-C sensor in the X100 wide open at f/2 has exactly the same depth of field as the full frame sensor in the D700 at f/2.8.

Now, you might wonder how I can say that the bokeh will be identical. After all, that is the quality of the out of focus area, not the amount of blur. Well, you would be right … I cannot really say that with perfect precision … the Fuji fixed lens may have a certain je ne sais qua … but then je ne sais qua I could do about that :-)

Instead, I am going to say that the bokeh will be close enough to give is a good idea of what to expect. And since I will display the results at web sizes, you might not be able to tell the difference side by side, were that possible at this time.

So back to the test. I have the Tamron 28-75 2.8 and the Tamron 19-35 3.5-4.5, both of which have the required 35mm focal length, and both of which are wicked sharp … although only in the center wide open for the 28-75. Obviously, I am forced to use the 28-75 wide open to replicate the DOF and guess at the bokeh, so that’s what we’ll do.

Remember the other question we might want to answer? What would it be like to shoot at one focal length all day? That one can be tested by anyone with an APS-C camera and any kit lens, since that can be set to 23mm and perfectly replicate the field of view. I recommend that you use gaffer tape to fix the lens at that focal length and then see if it does not drive you nuts when out and about.

Ok … I need to perform two experiments in order to really see whether I could stand to accept the focal length limitations of the X100. One involves fooling around with the camera around the house to see how it feels to stay away from extremes, something that I always enjoy. The other involves shooting people and / or a church or museum to see how it feels to have to stand at a certain distance from the subject for every shot of a certain type.

The first experiment I perform yesterday in the evening … just walking around the house. The second will have to wait a bit.

So … without further ado, I pointed the camera at the D300 box sitting up on a speaker and waiting for me to decide whether I will be selling it. Great camera, but it is almost the same size as the D700 and that makes little sense to me. This is certainly not the field of view I would choose for this shot :-) although I must admit that at a close subject distance, 35mm at f/2.8 will roll off nicely to a smooth background …


Poking the camera out the front door on a cool, crisp night let’s me see how it works for general scenery. And it works just fine. The Lilac bush is obviously rather dormant, but the detail is magnificent as it will be with the X100.


Going indoors, I want to grab a shot of the Christmas Tree as I prepare to take it down this weekend … maybe :-)


The field of view is fine for that shot. Again, a nice smooth background caused by the rather short subject distance ratio to the long background distance.


On the other hand, this focal length is not my favorite for isolating details such as the Christmas Piranha. So 35mm might be problematic for me in a church or museum. I like details and I like them fully framed sometimes.


Then again, you can get a bit closer to larger details as shown above, and they turn out well. The lighting here was old halogen above the mantel and tree lights below, so don’t get too excited about the weird color shift at the mantle. And here you can see that the background is already smooth, despite being only a few inches behind Santa. I predict a lot of people shooting the X100 wide open.


Yet back off even a couple of feet – again, above – and there is very little background blur, so be prepared for that. Portraits might be a bit tough if the background is not pretty. This camera will require the same level of discipline in choosing the right angle to the background and light as any small sensor camera. The focal lengths that wipe backgrounds out from a distance are not available.


One last shot of the mortar and pestle to show you that isolating a detail with any distance to the background does leave a very nice and smooth fall off. The Tamron is known for very decent bokeh, so this should be a pretty good simulation of the X100’s abilities.

Note that the Tamron does not have stabilization, just like the X100. I had to shoot the Piranha 4 times and raise ISO to 3200 to get one perfectly crisp shot. At 1600 I could not get one. This underscores the weakness Fuji introduced by not stabilizing either the lens or the sensor.

The D700 already had noise in that last shot at 1600 because I underexposed by a full stop to (a) protect the lights from the stove and (b) to get a faster shutter speed. I had to address this in ACR and with Topaz Denoise … the X100 is likely to be pretty unpleasant in such circumstances. Again I am thinking museums, churches and maybe parties. Stabilization always helps.

You can see that the background can be rolled off if you maintain a close subject distance. You can also see that you had better like this focal length if you are going to shoot it exclusively. I encourage you to perform the experiment I outline above before laying down a grand on the X100.

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