1502, 2023

Oscilloscope meets PPBAdv meets PSU’s

Linwood/ February 15, 2023/ Uncategorized

This is data, there are very few conclusions here, because I do not understand enough about what I am measuring, but it has some interesting photos (well, four versions of basically the same photo) of scope traces. I set up the following: A power supply (4 different ones), powering a Pegasus Powerbox Advance, which in turn was powering a 0.5A dew strip at about 50%, and I then measured three things: (1) what did the PWM output look like (not very interesting, as you expect a 50% PWM square wave), (2) what did the input power look like in terms of noise, and (3) what did the output power look like in terms of noise. Here is an example: Yellow is input power, Blue is output, and Purple is PWM. Underneath is a FFT showing the noise frequencies, basically just a lot of “stuff” spread over a wide variety of frequencies, but pretty far down. Note the yellow and blue are at 200mv per division, so

2803, 2016

D5 vs D4 in Basketball

Linwood/ March 28, 2016/ Nikon Hardware/ 0 comments

Here’s a followup. I shot Basketball this evening, and during warmup I shot some in the same environment with the D4 and D5, between 3200 and 25,600. I processed these in Lightroom with the same default preset I use, no special approach to the higher ISO. They are also a tad bright I think in a few cases, but I did not adjust exposure as I did not want to bias the ISO results. These are a center crop of the same portion of the frame, then I up-scaled the D4 a bit to be the same size. This is a scaled down view for here, but just click the image for a full size view. I’m going to stick with my “underwhelmed” answer, with regard to ISO. There’s a lot to like (I’ll try to post a followup on focusing, which I am still pretty enamored with, later). PS. Oh, wait… you wanted to know which was which? Can’t you tell? The D5 was on

2503, 2016

Those D4’s have great high ISO (D4 vs D5)

Linwood/ March 25, 2016/ Nikon Hardware/ 0 comments

I still want to see some humans under arena lights and similar, but a brief test of colors inside have taught me that the D4 is one heck of a good high ISO camera, and the D5 leaves me a bit under-whelmed. I started at ISO 3200 and went up to 204,800 increasing shutter each stop, shooting a flower under indoor light where it was steady. It’s at F2.8 and may not be perfect focus but seems close enough on the center to see some. I switched in Lightroom to Camera Standard, and synchronized the color temperature as I had the D4 set to a fined tuned WB that was a bit warmer. This is a standard preset I have, applied to all, with no attempt to better tune the high ISO settings, but it is the same preset on both cameras. Here’s what it looks like as thumbnails (click for larger image). You can see the background shadows drop into color noise a little later

1911, 2015

Cutting the Nikon 10.5 Fisheye

Linwood/ November 19, 2015/ Nikon Hardware/ 0 comments

After some research, I decided to remove the lens hood from my 10.5 fisheye. I use the lens periodically, but always on FX bodies. I shoot it in FX image size to give me a few extra pixels; this just takes that to the extreme. In the research I did, I found most people used a hacksaw to cut the hood, and did it in place. Some talked of cutting “until you hit the metal” which seemed like a bad idea, though apparently it works. I decided to take a different approach – disassembly, at least somewhat. Below are the steps I took with photos along the way. The first step was to remove the focus ring, and slide it up just above its normal location. It is a bit sticky (I think held with light adhesive) but it is easy to lift up and slide. Don’t stretch it more than you need to! This exposes a metallic gold tape held at each end with black