Aspheric drop-in lens for P60?

[gcbryan]

Have any of you who have been playing around with optics located any aspheric lens in a size (28.6mm diameter) and focal length that would be suitable as a simple drop-in for P60 hosts?

I know DX has a glass 28mm aspheric which I have. I have a plastic 28mm aspheric (from a DX flood-to-throw light) with a shorter focal length so it doesn't work as a simple drop-in.

Are there any others out there that you know of. I'm just interested to see if there are any better existing optics for throw without having to grind them or modify them in some way.

The glass aspheric I have does the job but shifts to blue along the outer edge and it shows the silver ring around the base of the emitter. This is not just a optics issue of course and if any of you have addressed improving beam quality with aspherics please post your findings as well.

The benefit of the plastic aspheric that I have is that it has a flange to help in mounting so the retaining ring can screw down further than the glass version I have with no flange.

I haven't seen every flashlight out there that uses aspheric lens but it seems to me the aspheric optic itself is always the weak link as in it may be a $60-$100 flashlight but the aspheric always seems to be of the $2.00 variety.

As it applies to P60 hosts I'm wondering/guessing that perhaps everything out there needs to be modified or customer made or I would have heard about it already...but it doesn't hurt to check! Anyone?

 

[rrt0000]

You know what... I was actually just thinking about this while driving home before. I'm currently researching online as well...

I'm thinking of just using a TIR optic as I cant seem to find any high quality aspheric lenses that look easy to mount.

Will be following this thread :)

 

[gcbryan]

For what it's worth, DX has some cheap TIR type snap-on optics for XR-E's that work well for what they are designed for.

They have a little collimating lens over the front of the emitter and otherwise are a internally reflecting lens. Plastic but good actually. I've replace a few reflectors with them.

The benefit is that the hotspot improves a bit but the big thing for me is it softens the hard outside edge of the spill since the spill is now less bright due to the collimator lens.

If you are using a XR-E at night and you are shining it at something in the distances you know how irritating it is for your eyes to be distracted by the sharp edge of the spill that jumps around every time you move.

They don't make it throw like an aspheric however.

 

[gcbryan]

All the same lines, are there any "turbo heads" that fit 6P clones? Some in the 50mm range?

 

[^Gurthang]

All the large "turbo" heads I can think of use a SF "M" thread, did 5Mega ever make a "C" thread large turbo head? I suppose you could use the LF M/C head adapter to mate a SF, 5M or LF large head to a 6P & clones

 

[Popsiclestix]

I know DX has a glass 28mm aspheric which I have. I have a plastic 28mm aspheric (from a DX flood-to-throw light) with a shorter focal length so it doesn't work as a simple drop-in.

The problem with long focal emitter lengths is that more of the light is lost because it is not captured by the aspheric.

All the large "turbo" heads I can think of use a SF "M" thread, did 5Mega ever make a "C" thread large turbo head? I suppose you could use the LF M/C head adapter to mate a SF, 5M or LF large head to a 6P & clones

Fivemega Deep Turbo C Head

 

[gcbryan]

Is there an aspheric "turbo head" available anywhere? I guess I'm thinking of something like the Tiablo A9 aspheric head add-on.

I understand that longer focal lengths aren't as efficient and would prefer a short focal length in a ready made turbo head but if it's something I have to mount then I can live with one that can just replace the front glass lens.

Inefficient still generally throws better than a reflector and I don't like spill in a dedicated thrower anyway.

 

[^Gurthang]

Popsicle,

THATs the one I couldn't remember.... now Bryan just has to find an aspheric lens to fit..... Bryan, don't forget Melles-Griot for aspherics.

 

[Popsiclestix]

Popsicle,

THATs the one I couldn't remember.... now Bryan just has to find an aspheric lens to fit..... Bryan, don't forget Melles-Griot for aspherics.

Any of the Mag aspherics will "fit". It's a matter of finding one with the right focal length as it does not appear to be focusable. I think you will have to PM Fivemega to find how far it is.

 

[^Gurthang]

Sicle,

+2 on 5M and the correct focus distance for one of his turbo heads.

On the subject of aspherics and focus. I recall there was a good thread some time ago relating the focus of an aspheric and best beam quality. Don't recall if there was recommended back-focal distences for lenses. Anyone recall that thread?

I know from my own 2D M@G thrower that a slight de-focus produces a much more useful hotspot rather than a sharply focused image of the die projected onto the intended object....

This was not intended to hi-jack the thread, just optical wanderlust.....

 

[gcbryan]

That's the main benefit of the focusable lights. For me, I don't really care about using one of those lights in the flood mode but I do like being able to easily defocus the beam enough to get a more round and slightly larger hotspot.

I also think the beam usually looks better to defocus and the short side rather than the long side.