Is G2 lens good for all visible wavelengths?

[dkumpula]

It is the lens mounts that have slightly different threads (not the lenses that are different).

Are you sure? I've measured G2s from DTR and G2s from Aixiz on several diodes and get minor differences in correction and power. I started a whole thread on the topic about a year ago and included my results.

My results were consistent when swapping one of DTR's G2s for another of his G2s as well as between Aixiz' G2 lenses. I've also noticed that the G2s from Aixiz are mounted at a depth slightly different than DTRs, but I didn't actually pull out the lenses themselves to compare them.

With multimode mitsu diodes you probably want shortest possible focal length to limit near field beam size.

Good advice!

-David

[catalanjo]

No ...not sure ...just deduced ....I stand corrected in the face of your actual comparisons David.
Unfortunately I missed that thread completely, and I think the change of mounting depth would make no difference since the focus adjustments would cancel this entirely.
Thanks for correcting me on this.
Cheers
PS. a link to that thread would be gratefully received if you have time to post it.

[dkumpula]

Sure thing, Catalanjo!

Here is the colimating lens measurement thread I mentioned: http://www.photonlexicon.com/forums/...highlight=lens

I believe the G2 lens from Aixis is actually slightly thicker (approximately 0.7mm) as both DTR's and Aixiz's G2s are mounted on the bottom of the lens holding 'barrel', but the measurement on the inside results one being higher than the other. Could just be a difference in thickness of the bottom of the barrel. I've never bothered to take one out to verify though, so I'll have to try that. This difference and the threads are the way I've historically told the two apart if I forgot to mark the lens barrel with who supplied it. In either case, yeah, I agree that it shouldn't matter if its just a little difference in mounting placement unless it was so far away from the base that it couldn't focus properly before hitting the diode mount.

Cheers!

-David

[catalanjo]

Many thanks David.....apologies are in order here .....looks like I did see the thread after all, and even posted to get the thread into my settings list ....... just didn't pay enough attention since I was looking for diode comparison data at the time.

Surprising I forgot about it really ...... since money is definitely involved here.

Probably already decided on 2mmFL lenses and it drifted out of the old grey cells

Cheers

[dkumpula]

Heck, I'm happy if I remember my own name each day much less every thread I've ever seen!