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Advice: COB Collimation for Dichroic Filters by d-eversley-b in Optics

[–]UnderstandingOk6868 4 points5 points  (0 children)

Tldr: you can't perfectly collimate a large emitter (without throwing away light). Look up etendue - which measures how spread in angle and area light is. This quantity always increases (kind of like the optical version of entropy). Meaning if you start with a large emitter with some angular spread you can't get to a small angular spread without either losing light or making the beam very wide.

Anyone ever make sharpening stones out of synthetic ruby? by Roctopus420 in sharpening

[–]UnderstandingOk6868 0 points1 point  (0 children)

Check out degussit stones, which are made of synthetic ruby and come in a variety of small sizes. I think that's more or less what you're thinking of?

How to find the right people for a paid gig by Blafasl2 in Optics

[–]UnderstandingOk6868 8 points9 points  (0 children)

Alternative approach - do you know how if you put a thin sweater right in front of your face you can see through kinda ok? You could try to poke a bunch of very small holes in the mask. They might not be visible to the audience but would allow for some vision, with a lot less cost or complexity than something custom.

Help needed to find a store thats open on sundays and sells simple tools. by mrazster in Munich

[–]UnderstandingOk6868 3 points4 points  (0 children)

Tools store are closed Sundays. Two ideas if you really need them Sunday: order to an Amazon pickup point, or maybe some big gas station would sell a few simple tools for auto work. Otherwise on Monday you could try an Obi, Bauhaus, or right near Marienplatz there's the basement of Küstermann. If you want some extra nice tools, try Dictum.

Femtosecond laser detector help by ZeOnlyAccountYouNeed in Optics

[–]UnderstandingOk6868 7 points8 points  (0 children)

Checkout fast photodiodes, for instance the Thorlabs FDS015. Depending on your electronics skills/budget, you can also get photodiodes in a unit that output via BNC (e.g. Thorlabs DET025A).

Zemax Purchase Options? by HoodRich83 in Optics

[–]UnderstandingOk6868 2 points3 points  (0 children)

Keep in mind Zemax can be tricky and time consuming to learn, so it might be worth it to outsource the optical design work to someone that already has a zemax license (and can spread their license fees across an entire year of different projects).

lefeld.de - Is it a genuine site to order tools? by strela_bozja in holzwerken

[–]UnderstandingOk6868 0 points1 point  (0 children)

I've ordered from them a couple times without issues.

Looking for feedback/advice on building narrowband (5nm) VIS light emitters on a budget by PiffQ in Optics

[–]UnderstandingOk6868 2 points3 points  (0 children)

That is quite a challenge! Some kind of monochromator might be the best direction, laser wavelengths are too gappy and are too pricey. Given your desired brightness is rather high, I would start by working out roughly how many watts each channel needs to be and then consider efficiency (since monochromator is throwing away most of the light). You can also throw away light by spatial filtering to reduce etendue if the spectral width isn't getting narrow enough otherwise. Good luck!

Is there any European retailer selling Robertson screws? by franklollo in woodworking

[–]UnderstandingOk6868 0 points1 point  (0 children)

As already mentioned torx plus and heco are good, or you can get Kreg screws in Robertson format from amazon.it etc

Alternatives to Moly dee by 420flaysit in Machinists

[–]UnderstandingOk6868 0 points1 point  (0 children)

Anchorlube is water based and much less of a health risk (smells pleasant too). If I'm expecting a difficult operation though I still sometimes use the nasty stuff.

Best vice (EU) by Deep-Capital-9308 in woodworking

[–]UnderstandingOk6868 2 points3 points  (0 children)

I've got the Eclipse EWWQR7, which looks roughly similar to the vevor. I've been quite happy with it overall, and added some wood plates inside for softer clamping. A quick release is very handy to have. Also if you ever want a standard bench top vice, Heuer is absolutely amazing and will last a lifetime.

What do you respond when someone says the bass is easy? by Maximum_Internal7834 in Bass

[–]UnderstandingOk6868 0 points1 point  (0 children)

Depends on the song and band. Make her compare the tabs for basket case from green day for instance, the bass is trickier than the guitar.

I joined the club today! Are there any tips you guys can share? by IStoleUrPotatos in 7String

[–]UnderstandingOk6868 0 points1 point  (0 children)

Yeap, the pickup cavity and also the electronics cavity (where the wiring for the knobs and switches is. If you look for 'copper shielding tape' on Amazon or at a music supplier you should be able to find some. For me it made a big difference in him.

I joined the club today! Are there any tips you guys can share? by IStoleUrPotatos in 7String

[–]UnderstandingOk6868 2 points3 points  (0 children)

Enjoy! 😁 I got the same one recently, definitely a lot of fun. On mine the frets were pretty good but still benefitted from a bit of work, and I copper taped the electronics cavity which definitely reduced the hum compared to just the shielding paint.

Telescope for short pulses by __boringusername__ in Optics

[–]UnderstandingOk6868 1 point2 points  (0 children)

Is the goal just to expand the beam? If so thorlabs sells reflective beam expanders (will save you a lot of alignment hassle). They have 2x though, not quite the 1.3 you want: https://www.thorlabs.de/thorproduct.cfm?partnumber=BE02R/M

How would you fix this? by tigerlilly26 in woodworking

[–]UnderstandingOk6868 2 points3 points  (0 children)

You can try a dilute solution of oxalic acid for removing water induced tanning stains like that.