【convoy】H4 and B35AM options are updated

It’s weird at certain angles I can see green and purple AR coating on M21F.

What is used in M21F? Because mine (arrived last week) looks purple and not green at all. But I am not very sure how to identify whether it is green or purple AR coating.

Stand next to day light (window) and look at an AR lens from the side, really flat angle (you are looking for the reflection). It should look purplish.
Look through the lens at a white object, for example I put lens above my white window frame and look through it at the frame, the window frame would now have a green tint.

Typical properly designed AR lens look like above: Purplish reflection from the side, and green color when you look through it at an object. I have Convoy M21B, M21E, M21F and two S21D’s, and all of their lenses look like this, meaning as expected. The amount of green that goes through is estimated to be very small. I have taken beam shots with and without AR lens, and cannot tell them apart as far as green tint is concerned.

This article describes why the green tint gets through and purple gets reflected. Hope this helps.
http://rick_oleson.tripod.com/index-166.html(link is external)
So, if coated lenses are purple, won’t my photos have a purple tint?
No…. actually, they’ll have a slight yellow-green tint – the extra light that didn’t get reflected passes on through to the film, and there’s a little more of the 550nm yellow-green than there is of the other colors. But it’s not very much – glass only reflects about 4% of light from each surface to begin with, and the coating has some effect at all wavelengths – so there’s maybe a couple of percent of extra green light getting to the film. For most normal photography, this isn’t enough to be noticeable in the pictures. However, some lens makers were concerned about it, and did something to reduce the risk of off-color photos.

yes, you can buy the lens directly

I can imagine it’s almost impossible to notice the difference when used alone. But when having 2 flashlights, same emitter, one with purple and one with green AR, the difference is clearly noticeable by eye. Green AR results in a more pleasant tint imho. I tried photographing the difference a while ago, but I’ve found it’s very hard to capture the difference on camera.

I am holding two lights right now, side by side. One has a greenish reflection, and one has a purpleish reflection. They are very obviously different, and others have told you this before.

4X18A GT FC40 sample
only 3 modes 5–30–100%
output current of driver ,4A
OP reflector

Very cool, Simon! This will be a great for long runtime and bouncing the light off a ceiling to illuminate a room.

Please ! Can I install sbt90.2 with 25mm MCPCB on 3x21a ?

How is the development of the 3x or 7x XHP70 flashlight going? Is the head size known already?

Simon, I bought a blue 18350 tube based on the above statements and expected one with rectangular threading. But to my surprise I received one with trapezoidal threading (which off course doesn’t fit). I’m a bit confused how this is possible.

His statement “apart from cyan ,other are all rectangular” only applies to complete S2+’s, not the 18350 tubes. He has stopped production on tubes with trapezoidal threads but that does not mean that he has sold out of tubes with trapezoidal threads. It’s clear from the 18350 tube product page that blue 18350 tubes still come with trapezoidal threads instead of square threads, since it says “blue-trapezoidal”.

Yeah I noticed that, but if you scroll down a bit:

It’s ambiguous to say the least and possible that I misunderstood, but I interpreted that as all have rectangular, except cyan, irrespective of what the buttons say. It’s not the end of the world, but at least let’s get it cleared up once and for all if possible.

Ooooor, maybe this should be read as “Of all currently sold S2+ flashlights, only the cyan one has trapezoidal threads, so if you want a matching 18350 tube, make sure you only get the trapezoidal tube if you have an older host with matching threads”. That would explain where part of the misunderstanding comes from. Having a feeling stupid moment here :person_facepalming:


I agree, it is confusing. Currently you can't buy compatible 18350 tubes for many S2+ lights due to the wrong threads being available.

better use 40mm MCPCB

size similar to 3X21A

i gave up 7x XHP70.2 ,Regarding the charging interface, I have to provide a 20V adapter, which will increase the cost a lot.
instead ,i plan to design 13* SST40/SFT40/519A ,
80A FET+constant driver is in design now ,

sorry , I didn’t express my meaning clearly。
i mean S2+ cyan flashlight has trapezodial thread, i didnt mean 18350 tube ,
pls ask refund on aliexpress directly if you can not use it

How about the 7x XHP70 with out a charging port?

On the one hand, it lacks portability, and on the other hand, I worry that users will install the battery backwards.

Thank you, but it would feel wrong to do so. At the end of the day it’s my own fault by making a wrong assumption. Hopefully it will help others reading this, so they don’t make the same assumption I did.

Was brewing some coffee to wake up and then it hit me. Since the cyan tube is not available at all, why not use the blue tube instead. The resulting colour combo looks quite ok, so happy ending after all.