When we average repeated captures of the same scene we hope for a steady improvement in signal to noise ratio. Each independent frame carries its own sample of random noise, and when we average those frames the signal adds coherently while the noise tends to cancel out. The result is a cleaner image that should… [Read More]
Aliasing with sinusoidal chirps
Today I will show you some plots similar to yesterday’s graphs, but with a different input waveform. For today’s post, I used what signal engineers call a chirp, which is a sinusoid of variable frequency. In this case, it starts on the left below the Nyquist frequency and ends on the right well above that…. [Read More]
Aliasing with more complex signals than sinusoids
A while back, I posted some examples of one-dimensional sampling and optimal reconstruction using sinusoidal signals. I’ve had some questions about other kinds of signals. In this post, I’ll look at targets that are similar to the USAF 1951 target, which has series of three black bars on a white background for various line spacings…. [Read More]
Fujifilm GFX 100RF inclusive review
The Fuji GFX 100RF arrived from LensRentals looking brand new. The first surprise was how compact it felt compared to the other GFX cameras. For a medium-format camera it is downright svelte, close in heft to a Nikon Z7 with a small 35mm lens. The design calls to mind a modern digital version of the… [Read More]
Fuji GFX 100RF shutter bokeh effects
Leaf shutter cameras have bokeh issues at high shutter speeds. A few months ago, I posted some really ugly examples from the Hasselblad 90mm f/2.5. We saw a bit of that with the GXF 100RF a few days ago when I posted the out of focus point spread function shots at 1/1000 second. Here are… [Read More]