OLcontest, modified light: 20cm fresnel lens thrower

122 posts / 0 new
Last post
MtnDon
MtnDon's picture
Offline
Last seen: 11 hours 21 sec ago
Joined: 08/27/2015 - 18:25
Posts: 3478
Location: Canuk in NM

Thanks.

CNCman
CNCman's picture
Offline
Last seen: 11 hours 46 min ago
Joined: 04/07/2018 - 10:10
Posts: 857
Location: Mississippi Gulf Coast

djozz wrote:
This is how the star is made.
Because I built in some tolerance, the die is focused at infinity when the slider is still 12mm short of the backside.

So when the slider is fully retracted, the focal plane of the lens is 12mm in front of the led, and the die projection is out of focus, creating a fuzzy larger spot instead of the smaller sharp square of the focused die.

So I positioned a cutout of a star (made from the lid of a coffee tin) 12mm in front of the led, which is sharply imaged at infinity by the lens, and because the led is only little out of focus, the throw is still not completely ruined (although I think it went down from 4Mcd to just 1Mcd).

Of course for maximum performance of the lamp, the cutout must be rotated out of the way.

If I find the patience I may have a go at a batman cutout, but it must be tiny, and the metal is tough.


.
That is amazing, very well done djozz Thumbs Up
Now that is thinking outside the box ! I never thought a Fresnel lens could do that !
You could do a Batman thingy in the clouds too.
No doubt this years competition is heating up Evil
BLF has other forums beat easily Wink
.

Think outside the box too long , cannot find your way back in.
Necessity is the mother of invention and the father is creativity.
Never give up, Never surrender. Make someone Smile today.

MtnDon
MtnDon's picture
Offline
Last seen: 11 hours 21 sec ago
Joined: 08/27/2015 - 18:25
Posts: 3478
Location: Canuk in NM

This is very cool…. something to think about

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

I tried a bat stencil, sawn out of thin aluminium with a fret saw, but I made it too big, the edges of the wings do not receive enough light so they appear not sharp.

So it must be made tinier, not sure if that can be done nicely with a fret saw. And I’m not sure about batman either, maybe I will end up with something entirely different Party

MtnDon
MtnDon's picture
Offline
Last seen: 11 hours 21 sec ago
Joined: 08/27/2015 - 18:25
Posts: 3478
Location: Canuk in NM

Cool! Beer Thumbs Up

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

Jeff51 just posted about a batman projection contraption that uses a 100,000 lumen Imalent flashlight as a light source, and a 25cm fresnel lens with fairly long focal length. Pretty cool too, but not as silent, and maybe a bit less throwy than this one.
https://budgetlightforum.com/node/75196

CNCman
CNCman's picture
Offline
Last seen: 11 hours 46 min ago
Joined: 04/07/2018 - 10:10
Posts: 857
Location: Mississippi Gulf Coast

The sky is the limit Cool

Think outside the box too long , cannot find your way back in.
Necessity is the mother of invention and the father is creativity.
Never give up, Never surrender. Make someone Smile today.

Skylight
Skylight's picture
Offline
Last seen: 2 hours 4 min ago
Joined: 10/01/2018 - 04:49
Posts: 959
Location: Europe

Looks pretty good actually! Big Smile

CRX
CRX's picture
Offline
Last seen: 1 day 19 hours ago
Joined: 04/02/2013 - 15:27
Posts: 4230
Location: Scotland
LOL Thumbs Up
MRsDNF
MRsDNF's picture
Offline
Last seen: 3 weeks 5 days ago
Joined: 12/22/2011 - 21:18
Posts: 13473
Location: A light beam away from the missus in the land of Aus.

Good effort djozz. Big Smile Beer

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

Tnx.
Today I got the 14AWG wire in so I could finish the battery carrier. I chopped the front section off the flashlight head 4mm above the shelf and sawed two grooves in the remaining rim to lead the ledwires to the side. Had to ream the holes in the shelf to 4mm diameter for these quite massive wires. Smoothed everything with sand paper so there were no sharp edges to cut into the wires. The wires were fixed in position with a good bit of kapton tape, does not look extremely profi but you are not going to look inside the lamp daily.
In the picture I show the old 18AWG wires too, so that you can see that 14AWG is a whole lot thicker.

I was lucky because with a 40T at 4.12V I measured 19.85 amps now, precisely what I was hoping for Smile

So now that the battery tube was shortened, I could check the maximum flood setting of the lamp, with the slider towards the lens with the battery tube touching it.

In the picture the flood looks a bit less wide than in reality because of the wide field of my phone camera. Trees are at 25 meters as always. (it looks like I borrowed Flahoholic’s van for the beamshot Smile )

MtnDon
MtnDon's picture
Offline
Last seen: 11 hours 21 sec ago
Joined: 08/27/2015 - 18:25
Posts: 3478
Location: Canuk in NM
Smile Nice
Xandre
Xandre's picture
Offline
Last seen: 4 hours 37 sec ago
Joined: 03/06/2011 - 07:02
Posts: 473
Location: South Germany

WoW

The beams are really awesome

Regards Xandre

Grigio
Grigio's picture
Offline
Last seen: 4 hours 16 min ago
Joined: 06/12/2019 - 12:14
Posts: 135
Location: Chiang Mai, Thailand

“The outside received a base-paint first, and then after some slight sanding, bright red!”

I missed the last update from a few days ago but “Wow, nice work, sir!” (Mooi rood is niet lelijk, toch?) Thumbs Up

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

mooi rood is niet lelijk herinner ik me uit de jaren 70 volgens mij, zegt iets over je leeftijd Smile Silly

MRsDNF
MRsDNF's picture
Offline
Last seen: 3 weeks 5 days ago
Joined: 12/22/2011 - 21:18
Posts: 13473
Location: A light beam away from the missus in the land of Aus.

Nice beam djozz. Ever have trouble finding a car park?

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

MRsDNF wrote:
Nice beam djozz. Ever have trouble finding a car park?

Not sure what you mean, but I do not have a driving licence, never needed one over here. (I can park a 20 meter steel barge though)
MascaratumB
MascaratumB's picture
Offline
Last seen: 3 hours 6 min ago
Joined: 10/29/2016 - 12:12
Posts: 6007
Location: Portugal

djozz wrote:
MRsDNF wrote:
Nice beam djozz. Ever have trouble finding a car park?

Not sure what you mean, but I do not have a driving licence, never needed one over here. (I can park a 20 meter steel barge though)

I guess MRsDNF was referring to your “spotting light” to spot a place for a car! It guess it could apply to the barge too Big Smile
djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

MascaratumB wrote:
djozz wrote:
MRsDNF wrote:
Nice beam djozz. Ever have trouble finding a car park?

Not sure what you mean, but I do not have a driving licence, never needed one over here. (I can park a 20 meter steel barge though)

I guess MRsDNF was referring to your “spotting light” to spot a place for a car! It guess it could apply to the barge too Big Smile

Speaking of which, ships often have great spotlights, my cycle trip to work is along a small part of the Amsterdam port and I’m always jealous of those marine mirror lights. They cost a fortune though..
Scallywag
Scallywag's picture
Offline
Last seen: 10 hours 55 min ago
Joined: 01/11/2018 - 22:23
Posts: 1608
Location: Ohio, United States

djozz wrote:
CRX wrote:
Cool Thumbs Up
Modified light category? Smile

A slightly modified SD2 Big Smile

Yes, quite the modest LED and optics swap with a driver bypass Wink
MRsDNF wrote:
Nice work bench. Looks like your almost finished. Beer

I could not get away with working on my dinner table. I have an Ikea Bjursta wall-mounted drop-leaf table next to my PC desk. It gets a bit cramped sometimes (about 90×50cm work area), but I quite like it. And it allows me to conduct mid-project research on BLF by simply turning in my computer chair, when I inevitably bugger something up

Old Lumens Contest 2020 - Hand-made light category

ZL SC62(w) | Jaxman E2L XP-G2 5A | Purple S2+ XPL-HI U6-3A | D4 w/ Luxeon V | RRT-01 | Purple FW3A, 4000K SST20 | Baton S1
Boruit D10 w/ Quadrupel Fet+1/Anduril | EagTac D25C Ti | DQG Slim AA Ti | Jaxman E3 | UF-T1 by CRX | Olight S15 Ti | Nitecore EX11.2
L6 XHP70.2 P2 4000K FET+7135 | Jaxman M8 | MF02 | Jaxman Z1 CULNM1.TG | Blue S2+ w/ ML Special | Thrunite T10Tv2
Supfire M6 3xXHP50.2, Sofirn C8F, Unfinished: Sofirn SP70, IYP07/Tool AAA hot-rods, Jetbeam E3S
Others: Nitecore EC23 | Nebo Twyst | Streamlight ProTac 1AA | TerraLux LightStar 100

jp9mm
Offline
Last seen: 7 hours 49 min ago
Joined: 03/30/2020 - 12:14
Posts: 468

Very cool Smile

Rdubya18
Offline
Last seen: 1 hour 26 min ago
Joined: 10/28/2018 - 18:42
Posts: 434
Location: Ohio

Holy spotlight … Batman Wink

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

Throwtest Smile

For who is into throw distance as unit (distance at which the illumination is reduced to 0.25lux AKA moonlight level), that is 4.36 km.
My Extech LT45 over-reads a bit, the Tasi 8133 makes it 4.24 Mcd but that may be under-read again. Let’s agree on rather throwy Wink

(I do not dare to use my Mobilux classA luxmeter too much lately because the cable-connection to the sensor is rather worn-out and fixing it will require a completely new calibration as well, which will cost me 300+ euros)

Tom E
Tom E's picture
Offline
Last seen: 30 min 6 sec ago
Joined: 08/19/2012 - 08:23
Posts: 13805
Location: LI NY

Outstanding! cool Great work, once again!!

Scallywag
Scallywag's picture
Offline
Last seen: 10 hours 55 min ago
Joined: 01/11/2018 - 22:23
Posts: 1608
Location: Ohio, United States

djozz wrote:
Throwtest Smile

For who is into throw distance as unit (distance at which the illumination is reduced to 0.25lux AKA moonlight level), that is 4.36 km.
My Extech LT45 over-reads a bit, the Tasi 8133 makes it 4.24 Mcd but that may be under-read again. Let’s agree on rather throwy Wink

(I do not dare to use my Mobilux classA luxmeter too much lately because the cable-connection to the sensor is rather worn-out and fixing it will require a completely new calibration as well, which will cost me 300+ euros)


For the Americans, 4.36km is about 2.7 cheeseburgers per bald eagle miles

Old Lumens Contest 2020 - Hand-made light category

ZL SC62(w) | Jaxman E2L XP-G2 5A | Purple S2+ XPL-HI U6-3A | D4 w/ Luxeon V | RRT-01 | Purple FW3A, 4000K SST20 | Baton S1
Boruit D10 w/ Quadrupel Fet+1/Anduril | EagTac D25C Ti | DQG Slim AA Ti | Jaxman E3 | UF-T1 by CRX | Olight S15 Ti | Nitecore EX11.2
L6 XHP70.2 P2 4000K FET+7135 | Jaxman M8 | MF02 | Jaxman Z1 CULNM1.TG | Blue S2+ w/ ML Special | Thrunite T10Tv2
Supfire M6 3xXHP50.2, Sofirn C8F, Unfinished: Sofirn SP70, IYP07/Tool AAA hot-rods, Jetbeam E3S
Others: Nitecore EC23 | Nebo Twyst | Streamlight ProTac 1AA | TerraLux LightStar 100

raccoon city
raccoon city's picture
Offline
Last seen: 4 hours 32 min ago
Joined: 10/06/2010 - 02:35
Posts: 15105
Location: रॅकून सिटी Palm Desert CA USA

Scallywag wrote:

For the Americans, 4.36km is about 2.7 cheeseburgers per bald eagle miles

I could go for about 2.7 cheeseburger right about now!  ;)

Where did I put that bald eagle?

thefreeman
thefreeman's picture
Online
Last seen: 4 min 1 sec ago
Joined: 01/06/2020 - 09:56
Posts: 308
Location: France

So much throw, nice work!

djozz wrote:

Speaking of which, ships often have great spotlights, my cycle trip to work is along a small part of the Amsterdam port and I’m always jealous of those marine mirror lights. They cost a fortune though..

Would These parabolic reflectors be appropriate for making somthing like this ? It doesn’t look very expensive. If I understand correctly the short focal lenght means that all light would be collected (expect in center), also it would not produce chromatic aberation as opposed to the fresnel lens.

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam

thefreeman wrote:
So much throw, nice work!

djozz wrote:

Speaking of which, ships often have great spotlights, my cycle trip to work is along a small part of the Amsterdam port and I’m always jealous of those marine mirror lights. They cost a fortune though..

Would These parabolic reflectors be appropriate for making somthing like this ? It doesn’t look very expensive. If I understand correctly the short focal lenght means that all light would be collected (expect in center), also it would not produce chromatic aberation as opposed to the fresnel lens.


those are uncoated aluminium reflectors, good for focusing sunlight for heating up stuff, but how is the light loss, and are they optical quality? If yes, they should be fun to make a recoil thrower with Smile

I’m very impressed by the optical performance of these budget plastic fresnel lenses btw, the throw per surface area is very similar to the GT reflector. What helps is that the light source is small and centered (as opposed to projecting an image i.e. a slide which is a large source), the fresnel rims are only maximally optimised for light coming right from the focal point which is the case with a led.

kennybobby
kennybobby's picture
Offline
Last seen: 1 hour 58 min ago
Joined: 05/10/2017 - 09:13
Posts: 639
Location: huntspatch, alabama
djozz wrote:
Throwtest Smile … My Extech LT45 over-reads a bit, the Tasi 8133 makes it 4.24 Mcd but that may be under-read again. Let’s agree on rather throwy Wink

Excuse my ignorance on these calculations—i see how you calculated the luminous intensity in candela, but i struggle to understand how the Luxmeter sensor area or solid angle come into play, or if they do? Does the sensor area not matter?

If the sensor area were known, would it be possible to calculate the lumens of the beam?

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

djozz
djozz's picture
Offline
Last seen: 2 hours 56 min ago
Joined: 09/07/2012 - 17:04
Posts: 17471
Location: Amsterdam
kennybobby wrote:
djozz wrote:
Throwtest Smile … My Extech LT45 over-reads a bit, the Tasi 8133 makes it 4.24 Mcd but that may be under-read again. Let’s agree on rather throwy Wink

Excuse my ignorance on these calculations—i see how you calculated the luminous intensity in candela, but i struggle to understand how the Luxmeter sensor area or solid angle come into play, or if they do? Does the sensor area not matter?

If the sensor area were known, would it be possible to calculate the lumens of the beam?


I measured the luxvalue in the hotspot at 12.33 meter, then calculated that back to 1 meter to get the candela-value.

I’m not sure what “solid angle” is, and the sensor area does not matter as long as it is more or less uniformly lit, as is the case because the hotspot is way larger than the aensor area.

Pages