280bp10 attempt

[Andrea B.]

If you look at the raw of the 260bp10 to see where the light was recorded, then you might be able to determine whether it is visible or IR (given that it cannot be UV-C). Of course, now that I think about it, there also is the possibility that a narrowband filter like that could be leaking longer UV up around 380-400 nm. (!!!) Now that would be truly annoying, wouldn't it?

 

Shooting into the sun like that can sometimes reveal leakage through camera ports or around windows or viewfinders. For example, at certain angles to the sun, I discovered that my D610 leaks around the upper LCD. I didn't see it for a long time, so perhaps the upper LCD worked loose over the years. There is always some surprise lurking to foul up our UV photos.

[Andy Perrin]

I still think you should try with your lens cap on, dabateman. Then we will see X-rays!

[Andrea B.]

Speaking of which, there are some photographers who work (have worked) "in X-Ray". Have you ever seen any of their photos? Quite interesting.

[Andy Perrin]

Yep, I forget who it was that had bunch of photos of everyday objects in X-ray images floating around. Someone also did flowers. It was fascinating.

[Cadmium]

280nm, 4s, ISO 200, I strongly doubt that is even UVB, seriously, it takes that long and the same settings to take some shots with a Baader U.

And UVC, I totally doubt that, given everything I have heard about natural UVC sunlight not reaching the ground.

 

What spectrum the light is coming from, I can't say. A leak in the out of band OD?

Have you tried stacking these with something rigorous? Like maybe 4mm of GG400? Of course the leak could be in the UVA.

 

https://en.wikipedia...violet#Subtypes

Ultraviolet C UVC 100–280 Short-wave, germicidal, completely absorbed by the ozone layer and atmosphere

[dabateman]

I actually believe the 280nm shot, it is of the sun after all. What exposure do you have shooting the sun with the BaaderU? I highly doubt it to take seconds.

I guess the only way to know for sure would be to photograph an LED light at 280nm. But even that may have stray bands. The 260nm, I think is mostly IR. The image is too blue and that is what IR typically looks like to me. But I may just do a controlled test llater to know.

The hase in the sky is really cool though, that you can see in the shots. Must be oxygen or something scattering the light.

[Cadmium]

You are right, shooting the sun directly would be a short exposure.

LED's can be fluky, stray bands... like you say.

Best way it to block out of band, start with GG. You could try with UV/IR-Cut, but that cuts IR. You could try with other longpass filters, red, IR...

If light gets through a simple red filter, then you have something other than UV.

If is is a leak in UVA, then you could stack with a Baader U, if it transmits, then you are seeing something from UVA.

Really fun stuff.

[dabateman]

I still think you should try with your lens cap on, dabateman. Then we will see X-rays!

 

No you can't use your lens cap to see xrays. You need to cut a small piece from your foil hat that you use to stop the government from reading your mind to do that. You may also be able to see the government rays that way too. I thought you knew that, as your hat has been leaky lately.

 

Yes Cadmium,

I think I will retest the 280nm, and use a steping series through all my band pass filters to see if I can track down any leaks. I think what I see for the 280nm is real and that might be the best way to track down a UV or IR leak.

[OlDoinyo]

I have said this before, but I really think that if one wants to do photography below 300 nm with consumer gear, that film is a better bet than digital sensors, which cut off in the 300-340 range. (There are the rigs which detect corona discharge from power lines in the daytime, but I do not consider those to be consumer gear.)