selfbuilt's Convoy S21E review

Some of you out there may remember me. :slight_smile:

I was never very active here, as I posted most of my reviews on candlepowerforums. I did have an account here, but I lost the password and that old e-mail is no longer in use, so I recreated one with my Reddit user name (should be self-explanatory).

As I explain on my newly revamped flashlightreviews.ca website, Iā€™ve decided to start doing some new reviews focusing initially on the 1x21700 battery class. These will be posted on my actual site, which has been updated with greatly expanded functionality, including a database feature and the ability for you post your comments right on the reviews there.

This is my second review since my return, and the first one focused on a budget light.

Convoy S21E

As I discuss in that review (and on my site), I previously stayed away from so-called budget lights for a number of reasons. But most of that was due to a very different environment and issues with budget lights when I first started reviewing in ~2008. I can see quite a few things have changed in the time I was away, and I thought it was a good idea to start with a new baseline of a popular budget model.

I went for all three emitter classes in this model, so I can directly compare performance (and have more than one sample to evaluate). I hope you find it useful - I certainly found the results interesting.

Hereā€™s a teaser runtime:

Anyway, I canā€™t promise to be very active on the forums going forward, but I will monitor for comments. And will try to stop by when I post a new budget light review you may find interesting.

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Welcome home.
That graphā€¦ instant recognitionā€¦ And it feels good : - )

Welcome seeing you again, and this time over HERE!
I bought more than a few flashlights after reading your reviews.
Some of them still in the rotation.

Good to see you here Selfbuilt! As an old CPF guy, I have missed seeing your stuff.
BTW, BLF is not limited to ā€œbudgetā€ light discussion or reviews. Lots of flashlights with reviews here are definitely NOT what I consider to be in the budget class. Certainly, do let us know when you do any reviews. I am sure that they will be welcome and appreciated here.

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Welcome back, cpfselfbuilt!
Your reviews are legendary. :slightly_smiling_face:

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Thanks for that. :slight_smile: I am still focusing on the multiple comparisons per chart, as always.

I have made a few minor tweaks to the charts though, to help with visibility.

Thanks - I still carry many of the same lights from my old review days. Itā€™s nice to have photon-monsters for show, but I am a lot more fussy about interface, beam profile and tint for my actual workhorse lights (and a few hundred lumens is typically still plenty).

Hey Mandrake, good to see you again too. Appreciate the warm welcome.

Yes, I can see BLF has evolved beyond its namesake, which is good to see. I would say that budget lights have also evolved beyond their origins, given by this example and a few other lights I have in testing in the moment.

Thanks, happy to be back!

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Yeah, some things have definitely changed in the time you were away. :innocent:

Given your interest in quantitative measurements, you might enjoy some of the developments along those lines. These range from simple, like using cd/lm to quantify how floody or throwy a light isā€¦ to complex and requiring additional tools, like beam profiling, spectral analysis, and the ā€œsnob indexā€.

Maukka and Parametrek developed a way to quantify how annoying the PWM or other oscillations are in light sources, called the Snob Index:

They also built methods for measuring the beam shape and color and various angles, as demonstrated in @maukkaā€™s FW3A review:

@Parametrek has also created a simpler beam profiler which is easier to use with far less specialized equipment:

Colorspace measurements have become pretty common too, using spectrometers of various types. One popular type is the Opple, but itā€™s fairly primitive, and can only detect a few frequency bands.

People also usually do runtime graphs inspired by yours, often using a free Android app called ā€œceiling bounceā€ from @zak.wilson. However, it often seems that people have low-resolution light sensors on their phones, or maybe just donā€™t understand how to do gain staging, so the graphs often come out blocky. It has worked fine on both the devices I tried it on though, giving me ~13 bits of precision.

There have also been some efforts to reclassify ā€œwhiteā€ itself, to better match what people find looks good in lighting tests. This would deviate from the BlackBody Line in favor of a more perceptual curve. At low CCTs (and some ā€œneutralā€ CCTs), the ideal line has a negative duv (pink bias), while at high CCTs it has a positive duv (green bias), with a pure neutral range betweenā€¦ because thatā€™s what people in studies perceive as looking good.

Hereā€™s a couple studies on thatā€¦

Thereā€™s more, of course, but thatā€™s probably plenty for now. :sweat_smile:

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Thanks for all the links ToyKeeper - I look forward to reading them.

And thanks for all you do on the open-sourced UI front (with Anduril, etc.)!

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Thanks for another fine review.
I have a variety of lights ā€“ Zebras, HDS, Emisar, Reylight and the new Quarks ā€“ and the Convoy 21e is my current favorite for dog-walking.
This light really shows off the strawberry color on Babe, our long-haired Dachshund.
I like the beam and tint on the 519a emitter. The size, weight and ergos make the light feel great in my hand.
Iā€™m also a 21700 convert.
All this plus the nice Convoy price.
I have three so far.

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Hey there @selfbuilt , welcome (again) to BLF, really glad to see you active here! I just now noticed this issue. I can help you regain access to your old account and merge this new account with it so you can use your current registered email. Just send me a PM and Iā€™ll help you out.

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Looks like the account merge got taken care of, since it now says you joined in 2013. However, it also says your first post was just a couple weeks ago. Did you have zero posts on your account before the platform migration, or did the account merge just not pick up your old posts?

Looks like itā€™s up to date now, maybe it was just waiting for a periodic stats update run.

Itā€™s still showing me 3 topics created, 14 posts created, and the first was on 2023-04-18. I.e. no sign of life before a couple weeks ago, except that the account join date is in 2013.

Could be due to signing up and then never saying anything, or it could be a side effect of how the merge worked. Itā€™s hard to tell.

I think the underlying problem is that some phones are configured to only update on large changes so the screen brightness doesnā€™t fluctuate rapidly because

  • Nobody could possibly use the light sensor for anything else
  • That kind of smoothing couldnā€™t possibly be done at a higher level than the light sensor driver

My Pixel 4A is not consistent about its large jumps. I can see a whole bunch of different values somewhere around, for example 80 lux when shining moving a light around to produce large fluctuations. I suspect this is happening at the OS level, as Iā€™m not getting that behavior on a Pixel 3A XL running a third-party Android build.

I may have to install a third-party Android built on my main phone to test this theory. If the dev tools used to build Ceilingbounce werenā€™t abandonware, I think I could probably force updates.

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