Ulf Said

[Cadmium]

Ulf said, "UG2A"

I said, "2mm?"

Ulf said, "Thinner"

I said, "1mm?"

Ulf said, "Thinner"

I said, "How thin?"

Ulf said, "0.7mm"

I said, "No, that is too thin"

 

However, Ulf was persistent...

 

[Andy Perrin]

What does Ulf want it for?

[ulf]

I want it to experiment with for alternative BUG-vision stacks.

 

I have been experimenting with stacks using different thicknesses of UG5-type glass together with S8612.

At my location att 55 degrees north the UV/VIS content and image result can vary quite a lot.

 

When I got my UG2A 1mm and tried it late afternoon, early in the spring, (little UV) I got some interesting images with a nice UV/VIS ratio.

Especially images of flowers with interesting patterns in the upper UV-A region showed something I liked to explore further.

Later when I tried that filter with more normal UV-levels, the patterns came out way too dark, just as Steve pointed out when I first wrote about the UG2A 1mm.

 

With UG5 I got different degrees of UV-signature, depending on the light, but often less dark than Steve has seen.

Sometimes 1.5mm has not been enough and then I got a good result with 2mm.

 

For UG2A I hope to get a similar effect by shifting towards a thinner filter to get less dark signatures with that glass type.

 

I hope that a stack of UG2A 0.7mm together with S8612 2mm will make a new interesting alternative IRBG stack as a complement to the typical UG5 1.5mm stack.

 

The UG2A gives more green in the images and is for me easier to white balance to get a pleasant image.

[Andy Perrin]

Ok, looking forward to the posts here when they come.

[ulf]

Most flowers are gone for the season now, so it might take some time.

 

The filter must get here too.

[dabateman]

I didn't realize the UG2a was that different than the UG5. I just thought it was a thickness thing.

So will a Bug2 filter be made in the future?

[ulf]

I didn't realize the UG2a was that different than the UG5. I just thought it was a thickness thing.

So will a Bug2 filter be made in the future?

It is difficult to process such thin filter glass and I think Cadmium had to source them elsewhere.

It might be too expensive to make a BUG2 with this glass.

So far it is just my guess that a 0.6-0.7mm thick UG2A will be a good component for such a stack.

 

If the result is good and there are enough demand it might be a valid business case that work for Cadmium.

 

That is up to him to decide when we know more, in the future.

[Cadmium]

UG2A is more like UG1 than it is like UG5. UG1 is three times the strength. UG1 1mm is like 3mm of UG2A. So in reverse, UG2A 0.7mm would be like UG1 0.23mm.

UG1 0.23mm should transmit closer to UG2A 0.7mm than UG5 would (any thickness).

UG2A and UG5 have different plots.