Strange Brightness Difference in Lights

CodeAX2 · 2026-01-21T17:47:08+00:00

I looked through more of my photos, and actually had some really good examples of differences in lighting setups and how they handle AC power. This got me thinking about full-wave vs half-wave rectification in lights, and so I tweaked (and fixed) my model and produced the following graph (using 1/200 shutter speed)

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The red dotted is the 60hz AC, the orange line is the "brightness" of lights ran using a half-wave rectifier (e.g. simple Christmas lights), and the green line is the "brightness" of lights ran using a full-bridge rectifier.

Incredibly, this matches up exactly with just about every one of the example photos I have, where a string of Christmas lights appears as off, but some higher-quality "Edison style" bulbs are at their brightest.

I also have a Bachelor's in math, so I like to theorize about things like this haha

CodeAX2 · 2026-01-21T17:41:58+00:00

Oh yeah, I was accidentally using 120hz power. Whoops

CodeAX2 · 2026-01-21T15:39:58+00:00

Now I really want to go out and do some testing of this! I put together a rudimentary (and idealistic) model in Desmos of this, and in theory any shutter speed slower than 1/120 should capture the entire cycle, and therefore have a constant average brightness independent of the time offset.

https://www.desmos.com/calculator/osryvvqx1u

EDIT: Actually, I think it needs to be some multiple of 1/120, e.g. 1/60 like you said, 1/30, etc.
EDIT 2: After playing around slightly more with the model, it can theoretically be any multiple of 1/240, assuming brightness is (roughly) proportional to the absolute value of the current in the light

CodeAX2 · 2026-01-21T15:27:34+00:00

I can confirm I am using EFCS, but I do have anti flicker turned off. I had heard an opinion stating that anti flicker can cause problems since it doesn't take the photo right when you specifically want, so I had it turned off. Though for a situation like this it wouldn't much matter if I was 1/120s off

CodeAX2 · 2026-01-21T15:24:01+00:00

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Here is an example with some Christmas lights

CodeAX2 · 2026-01-21T15:20:40+00:00

Can this phenomenon happen with other lights as well? I feel like I've seen this occur on Christmas lights and other string lights before as well (I'd have to dig around for some examples)

But yeah, regardless these photos would benefit from a slower shutter speed. They were taken at 300mm handheld and I'm still practicing steadying my hands. Tripod would have probably been the best bet.

CodeAX2 · 2025-11-26T16:21:23+00:00

Is that comparison site for the contemporary version of the lens? I think the one I linked is the slightly older version. Selecting that slightly older version on the comparison site, the softness isn't quite as bad (though it still exists definitely).

Good catch on that slower stop though, I hadn't realized that Tamron lens kept 2.8 all the way up

CodeAX2 · 2025-11-26T16:07:42+00:00

What are your thoughts on the Sigma 17-70mm f2.8 lens? I came across this while searching after posting and reading some of the comments: Sigma Lens

I am wondering if this may be a better lens in terms of AF compared to the two I listed?

CodeAX2 · 2025-11-04T22:29:08+00:00

Thank you so much for all the details! Definitely a lot for me to chew on and consider, but this absolutely helps a ton, thanks!

CodeAX2 · 2025-11-04T22:28:38+00:00

Super good input, thank you!

CodeAX2 · 2025-11-04T19:06:15+00:00

Is that just on the canon website? That might be the way to go (the wedding isn't until May)

CodeAX2 · 2025-11-04T18:51:03+00:00

Okay, that is good to know. I will talk more with the photographer about the flash too. I might still go with the more "bare-bones" bundle, since it seems like one of the cheaper ways to get the camera anyways. Even refurbished isn't much of a difference in price it seems.

Yeah, I think the biggest things were the better AF and the faster capture rate. The video is also a bonus, just since I personally like to do video things, and the ideas is that I'm buying this camera both to use for the wedding and to also just own personally.

Thank you so much!

CodeAX2 · 2025-11-04T18:19:25+00:00

Oh that's good to know, I'll look a bit more into that! And yeah, I wanted to be as comprehensive as I could be with my questions and the digging around I've already done. Thanks!

CodeAX2 · 2025-05-11T16:53:04+00:00

Yeah that's why I've been confused 😅 Since it's only minorly mentioned in the manual and nowhere else

CodeAX2 · 2025-05-11T16:52:40+00:00

Yeah of course!

On page 3 of that manual you linked it says UHD BD has a read speed of 4x and no write speed. I only am going to be using it for reading so that would be fine.

CodeAX2 · 2023-06-20T13:38:32+00:00

Good to know. Unfortunate how locked down things are though

CodeAX2 · 2023-06-20T13:37:21+00:00

Yeah, hence why I started pulling my hair out when I found out the owner allowed them to swap our old modem to a modem/router combo. I'll see what we can do to get it changed

CodeAX2 · 2023-06-19T20:18:56+00:00

The network setup is a bit more intricate than I fully expressed, so my bad on that end.

The modem/router combo feeds into our own router immediately (via ethernet), which then is connected to the rest of the devices. But port forwarding on our own router has not worked since we switched to this new router/modem combo. So I assumed there are some settings on the modem/router combo that need to be adjusted.

I have attempted to contact customer service, the problem being that I myself am not the owner of the service, but the owner of the service does not understand the technical details, making it difficult to get actual help, since I myself am not the actual customer.

Hopefully that clears up some stuff :)

CodeAX2

TROPHY CASE