A thrower has a “V” pattern to the collimated beam, in most cases, and as such it needs some distance to get the hot spot out there. It can be difficult to get a proper long distance measurement, so it would seem that 5-7M is pretty common range. I use 5M, once in a great while I’ll go to the trouble to go further out.
This is all good, seeing we are in the same approximate range of performance on similar performing mods/LED's.
Dale - I'm basing the 10+ meters on what manxbuggy1 and rdrfronty told me, and think they posted. They did this, from what I recall, at a wide range of distances and found on most throwers, going above 10 meters resulted in a more accurate result, then after that all the way up to 100's of meters (I believe), it didn't matter - they would get the same results: for example, 20 meters or 100 meters did not matter - same calculated kcd. This is what they said/posted, so I've been going on this premise. I think still til this day, they did the most extensive amount of testing on measuring throw, and published results that has ever appeared on BLF. This is based on the # of lights, distances, even multiple meters.
Also I know a dedomed modded TN31 I tested at ~3.5 meters that I sent them, they tested and got the same results at the same 3.5m distance, and then when tested at 10 meters (or just over), got about a 10% bump. That proved to me what they've been posting has verifiable merit. Of course in this case, it's only 1 light, 1 type of light, and maybe there's issues with the meters as well. Also for long distance testing, I'm sure humidity, temperature and other factors can contribute to inaccuracies, but that's why it's best to keep the distance short, but just over that "magic" point, which may be the focal point, as you mentioned. Actually as a result of this TN31 testing, I bumped my indoor distance to 5m, longest I could manage and still read the meter myself.
I tested a handful of thrower lights in similar fashion - indoors at 5m, then outdoors at about 10-12 m, and got similar bumps, always seemed to be some low percentage, but measurable. Think'n 5-8% at most.
Once in a great while I’ll measure out the 15M distance, set the meter on a tripod with a camera on a tripod in front of and beside it, recording video. Then when I shoot the light at the meter I have it recorded so I can go back and get the meter numbers. It’s a PITA but the only way I could figure out to do it by myself. I guess it would be good to measure multiple lights while the camera was recording, simply announce the name of the light so you’d know what numbers went where when you played it back and wrote it all down. 
Edit: I should probably set this up and get 15M readings for my L6 that has posted 439Kcd and the L2 XHP-35 that’s done in the lower 300’s. Probably the TN42 that’s shown 702Kcd at 5M as well. Then see what comparative numbers show up at the greater distance.
EditII: Come to think of it, isn’t the night before Halloween a New Moon?
I can measure 10m indoor and I put my meter on a tripod. My meter has min and max store function. I used max to read. Values after I shot it with L2
Yea, the tripod deal for the meter is a great setup. I grabbed my daughter to hold/read the meter at the measured off distance. The camera setup is cool.
Dale - I was totally unaware of an L2 w/XHP35 did that well, that's great news! Been begging for #'s in the past, but didn't get answers - not you, but others building XPH35 mods. Do you have posted details on the full mod somewhere? I never saw where an XHP35 HI (if it is a HI) can beat a dedomed XPL V6 or XM-L2 U4.
Also if you have details somewhere on that L6 that does 439 kcd...
Take a look on the Convoy L6 thread if you have time .
I only remember he used MTN buck driver , dedomed xp-g2 with the smo reflector.
No luck - found posted domed XPH-35 doin 170 kcd in a L2, so maybe he sliced dedomed it. He mentioned it could double the kcd.
I don’t remember exactly, will have to dig up notes. I do remember that my MaxToch 2X Hunter with XHP-35 does 322Kcd as compared to some 332Kcd in stock trim, but at significantly more lumens output. I could have misquoted that L2 XHP-35, my memory may have supplied the 2X Hunter number instead. (old age, not what it’s wrinkled up to be)
Easier to just go take a new reading… 
Back in Dec/Jan '14, I measured a MaxToch 2X for JMPaul320 at 358 kcd, taken at 5m, mine measured 311 kcd. Can't find notes on it, but at that time, must have been dedomed U2 1A's. I did more tweaking on JMPaul's 2X than my own (focusing and more aggressive resistor mod), and never went back to tweak my own.
Could probably do better with a U4 or XPL W2 nowadays.
My Convoy L2 does have a sliced XHP-35 in it. I don’t remember doing it but it shows as a sliced one as compared to an HI. (the little striations on the surface from the blade) With the cells in it and rested, didn’t even check voltage, it just gave a 209Kcd after 30 seconds. (234Kcd at start)
The 4 little 26350’s are at 4.0V, driver is a modified LD-2 from led4power, I modded it to do 3.13A at the tail, 2986 lumens otf. (from memory, don’t quote me) I’m serious, if I walk across the house and take a meter reading and don’t write it down, come back to my computer to figure the lux… there’s every chance the meter’s reading has disappeared from my head. I can even say it to myself as I traverse the house, only to forget it or be unsure of it when I sit down. Bothersome stuff, that. When I just now pulled the 4 half cells out of the L2, I’d forgotten they were half cells, was expecting two 26650’s. Duh! lol
Dale, believe me, I'm very close to that, and can totally relate 
. I got a pretty good notebook on mods/measurements, including indexing, but only good if I remember to write stuff down in it... Sometimes, like today, I bring it to work with me, if I remember to.
I can’t find any notes on when I sliced it, not even in messages to JDub on these Convoy lights. Gotta be something somewhere, but can’t find anything.
And I am entering the zone… gotta get ready to go shoot pics at a wedding rehearsal and then the wedding tomorrow so I’ll be slammed for the next week at least working on the multitude of pictures we invariably take at a wedding. Tonight begins it, tomorrow my old dogs get tortured!
Have fun guys, catch ya on the flip flop! 
Here is where you talk about slicing the XHP35 in the L2.
Wow. I clearly remember the incident with the fox, totally lost the part where I sliced the dome off the XHP-35. lol Thanks Easy, prc8 it.
Did some searching and went through fasttech’s selection and found some options for single 18650 larger-than-C8 reflector lights.
Fandyfire SP02:
https://www.fasttech.com/product/1343110-fandyfire-sp02-5-mode-400-lumen-led-flashlight
Trustfire T1:
https://www.fasttech.com/products/1601/10000663/5231200-trustfire-t1-led-flashlight
Brinyte S28:
https://www.fasttech.com/products/1601/10000772/4090900-authentic-brinyte-s28-led-flashlight
Sipik HK60:
https://www.fasttech.com/products/1601/10000619/1742400-sipik-hk60-900lm-1-led-5-mode-cool-white-led
Brinyte XML-900:
https://www.fasttech.com/products/1601/10000772/1103800-brinyte-xml-900-1-led-5-mode-900-lumen-white-led
SME-T622:
https://www.fasttech.com/products/1601/10020308/4325101-sme-sme-t622-led-flashlight-set
Uniquefire UF-X6S:
http://www.icebay.com/uniquefire-uf-x6s-cree-xm-l-t6-led-1000lm-5-mode-white-flashlight-w-strap-grey-2-x-18650.html
This light is sold out everywhere that I could find except the above address. Note there might be some issues with converting this light to 1x18650. Also the ZY-T13 in the BLF link, which is also sold out most everywhere.
I just ordered the fandyfire SP02 to mod because I want a serious but lightweight thrower. My UF-1504 aspheric light is a serious thrower, but it is so heavy I’m less likely to carry it. Also the reflector light can be made more water resistant.
The Brinyte S28 looks like it’d be a nice light. Very good beam profile from the reflector. The SP02 will be very ringy, horrid beam. The Sipik HK60 is interesting, a variation on the HD2010
Easy, since you are in the US( Dale too) here is the ultimate deal for you( sadly i cant order one more)
The best 50mm+ single XPG2 thrower for XPG2 modding at a great price too, i count it a luxury version of the C8 and ofc ways better, mine hit 280k cds with s2 emitter, sadly i lost it while in the woods a year ago
Damn you have damn good prices in the US…. as usual
In the picture the head looks much bigger than a C8
Thanks, that looks like a good option. I guess there are more options for this size light than I thought.
The reflector looks great but the light is put together a little odd.