MC-E beam angle and utility

[gcbryan]

I'm a little confused by terminology and prevailing wisdom I guess regarding the use of a MC-E in a dive light in limited viz conditions.

Since it has multiple emitters it can't be focused in as tight a beam as a small single die emitter. Limited viz conditions are more trying due to the backscatter so it's generally accepted that MC-E's produce too wide a beam for signaling partially due to the backscatter problem.

I think I'm more or less correct in stating the things that I've read in this way.

Yet, so far at least, I'm not having those problems with the MC-E. I'm not talking about multiple MC-E light heads for cannister lights of course but just a sincle MC-E hand held.

I guess I can see the description of wide angle as being correct in one sense but in another it seems tight to me. If I take the light out to my backyard it's lights up the entire backyard so that's a wide angle. But the 8 degree or so brighter central spot is very distinctive and I can see that with no problem.

Underwater signaling with the tight central spot is no problem. The spill is wider than some of my other lights but when diving so far I've found this to be an advantage as I am able to see more rather than just see what is in the spot and then have the surrounding area be black. Up close the spill is an advantage and when shining the light out into the void it's the central beam that's doing the work.

Backscatter with this light could be a problem if viz was 6 feet rather than 15 feet I suppose and I would just switch back to the 50% power setting.

I'm just trying to figure out whether or not I understand what people are referring to by considering this a wider beamed light. Do I just have a particularly good reflector and in effect have a tight beam by anyone's definition or is it the angle of the spill that people are talking about?

 

[Packhorse]

For me ( and this is personal opinion) I find the amount of side spill from the MC-E's too much for low viz diving conditions. This results in to much back scatter.
Single MC-E set ups with proper MC-E reflectors dont really have the problem as much as a home build set up trying to cram 3 4 or even 5 MC-E's into a 50mm reflector not designed for MC-E's in the first place.

As for signalling a MC-E can be OK ( much better than a fixed focus 10w HID) but a single XR-E aspheric will produce a more intense beam and be a better signalling tool.

I was on a dive last week in a cavern. The viz was pretty good at around 10-12 meters but inside the cavern the viz was terrible due the amount of Big Eye ( small fish with big eyes) in there.
My W200/MC-E lit up the cavern really well but I couldnt really see past the fish. The W200/R2 managed to cut through the fish much better allowing me to see what was behind them.

If only there was a small single die LED with a dispersion angle of 90 deg or less that could produce 2000 lumen with out drawing huge current.

 

[gcbryan]

Thanks for the detailed explanation.

I have a W200 coming (and have had for the last month and a half!) and I think initially at least I'll use it stock as a backup. That and the single MC-E primary should make a good combination.

FYI- someone disassembled and measured the o-rings in the Cree MC-E/P7 light and posted the results as follows:

Bezel o-ring Inside Diameter 46.22 x Cross Section 2.046 Hardness shore 57
Body 0-rings Inside Diameter 20.87 x Cross Section 2.215 Hardness shore 55

I understand that if I were to replace them I should probably use duro 70 but as far as I can tell from most of the online sites that sell o-rings these aren't standard sizes. I can't find them.

Am I just reading the charts wrong? (I realize they're in mm).

 

[gav6280]

Have you looked at polymax?

http://www.polymax.co.uk/acatalog/O-Rings_2.5mm_Cross_Section_NBR.html

 

[gcbryan]

They don't seem to ship to the U.S. That would probably be an expensive o-ring anyway. I'll have to look a little harder.

Have you looked at polymax?

http://www.polymax.co.uk/acatalog/O-Rings_2.5mm_Cross_Section_NBR.html

 

[H20doctor]

here in the Pacific Northwest , we have vis down to less than 3 meters.. and i cant see a w200 cutting through our waters, Maybe you could provide video Packhorse ? id love to see that so I could compare it to a 10 watt HID , say like a OMS or a Halcyon

 

[Packhorse]

No video sorry, but a pic of a W200 R2 on the left and a 10W HID ( Wellch Allyn fix focus as used by most HID dive lights) on the right.

I think the photo speaks for its self as to which would cut through murky water better.

 

[gcbryan]

No video sorry, but a pic of a W200 R2 on the left and a 10W HID ( Wellch Allyn fix focus as used by most HID dive lights) on the right.

I think the photo speaks for its self as to which would cut through murky water better.

It also shows which one would let you see more underwater once you got to where you're going.:D

Seriously, that does look like one tight beam. I'm hoping that the new W200 with the possible Q5 will look like that.

 

[Packhorse]

No the q5 version will not look like that. That one uses a r2 and aspheric lens.

No doubt about it the HID puts out more total light and is a better light fit moderate to good vis. But in low vis the w200 with aspheric wins. In other words best to have one of each!

 

[gcbryan]

Could you simply drop in an aspheric lens into a stock W200 and get much the same effect?

No the q5 version will not look like that. That one uses a r2 and aspheric lens.

No doubt about it the HID puts out more total light and is a better light fit moderate to good vis. But in low vis the w200 with aspheric wins. In other words best to have one of each!

 

[gav6280]

It also shows which one would let you see more underwater once you got to where you're going.:D

Seriously, that does look like one tight beam. I'm hoping that the new W200 with the possible Q5 will look like that.

Threre is a Q5 version?

 

[gcbryan]

Threre is a Q5 version?

The newest model W200 may be a Q5. I noticed they're listed that way at KD and Packhorse noticed that the board or something looks like that of the Q5.

I ordered my W200 from DX but the W200 seems to be changing all the time with flicker/no flicker, less and then more o-rings, no driver and then driver, so it may be that the latest W200 is a Q5.

 

[Packhorse]

Could you simply drop in an aspheric lens into a stock W200 and get much the same effect?

Of course, but its a bit more involved than just dropping in the aspheric.

I cant find the W200 on KD???

 

[gcbryan]

I just looked and I can't find it now either. I don't know where else it could have been though?

 

[gav6280]

http://ultrafire-shop.net/UltraFire_Shop.php?view=productPage&product=8&category=10

 

[gcbryan]

http://ultrafire-shop.net/UltraFire_Shop.php?view=productPage&product=8&category=10

Thanks. My light was back ordered for a while so maybe that was because of the new version being produced. Still waiting for delivery any day now.

Have you had a chance to dive your new MC-E yet?

 

[gav6280]

Thanks. My light was back ordered for a while so maybe that was because of the new version being produced. Still waiting for delivery any day now.

Have you had a chance to dive your new MC-E yet?

No not yet, as just paid my last payment (£800) on a holiday for Feb on Blue Horizon in the Red Sea. So hopefully now will be able to, also i only get Mondays off work....

Please do let us know what happens with your W200 as if it's now finally an Q5 or even R2 and a proper driver, i will definitely be ordering one too.

 

[gcbryan]

I don't know if I'll know for sure. I'm not planning on taking it apart for the moment. I'm just going to use it as is for a backup. I can try to guess as to it's brightness when I take it diving.

This thing is taking forever to get here. Getting the MC-E was fast by comparison!

Packhorse's latest W200 came from DX. I'm sure he can ID as whether it's a Q5 at some point.

I'm working on a "harder" "soft" Goodman handle for a couple of lights now. I like the PVC method. I'm even use some to firm up the Oxycheq sock.

No not yet, as just paid my last payment (£800) on a holiday for Feb on Blue Horizon in the Red Sea. So hopefully now will be able to, also i only get Mondays off work....

Please do let us know what happens with your W200 as if it's now finally an Q5 or even R2 and a proper driver, i will definitely be ordering one too.