Proof of concept: UV-reflectance stacking with MP-E 65

Zeidora

EOS Rebel SL2
Feb 15, 2015
668
10
#41
So you are using a $1,000 flash as an optical triggering device to trigger an underpowered $20 flash? I don't see that as making any sense, why not just plug the Metz into the PC port on the camera?

But a simple 'studio' light is going to give you way more bang for the buck anyway and get you to the power output you need rather than mess around with AA batteries.
The problem is the sync voltage of the Metz, which will fry the 5D electronics. At any rate, now have a PC Buff white light 1600 so can radio control that.
 

Zeidora

EOS Rebel SL2
Feb 15, 2015
668
10
#42
Very cool. What orchid? The local terrestrial orchids (Spiranthes) tend to be of this size or a little larger (2 to 3 mm at most). https://en.wikipedia.org/wiki/Spiranthes

Also, do you have a recommendation on a 365 nm UV flashlight?
It is an epiphytic tropical orchid in the genus Oberonia. Do some systematic/phylogentic work on that genus, and got interested in the pollination biology because everybody asks me that question.
 
Feb 23, 2016
1
0
#43
Zeidora, you might want to check in with Dr Klaus Schmitt who has done a substantial amount of UV macro work. He knows which macro lenses transmit UV, although I see that you purchased the Coastal. I also had several thoughts. The best lens I know of in the 1x-3x range is a lens taken from the Minolta Dimage 5400 film scanner. Like enlarging lenses, it is not the sort of lens that would come into contact with UV and therefore it may not have any coating that would hinder UV transmission (but I did not test).

I do a great deal macro work with plants in the studio. The greatest boon to my photostacking has been continuous light LEDs (no heat). I have not checked as to whether they have UV LED panels in the wavelengths you need but they may. I did a brief internet check, and it seems there are a bevy of products in the the various UV wavelengths for a number of industrial uses. That way you won't have to blast the full spectrum Bluffs to get sufficient illumination.

Keep up the good work.
 

Zeidora

EOS Rebel SL2
Feb 15, 2015
668
10
#44
I've been in contact with Klaus before, know his very useful website. There is also the ultravioletphotography forum. Thanks for the pointers re UV LEDs. As far as i understand UV LEDs, they are very narrow in terms of wavelengths, which result essentially in monochromatic (B&W) UV reflectance images. I am not aware of full spectrum UV LEDs (say 320-400 nm). I think I rather have to be careful in re-calculating DOF and step size, and play with distance vs output of flash unit, or find sweet spot with ISO setting. A UV pass IR block filter may be the holy grail, but not aware of one, and at the size I need it would cost a decent fortune. UG11 is blocking visible, but not IR, and then is also attenuating UV. Tried that with the Metz.

The scanner lens is an interesting idea. But first I'll fiddle a bit more with the Coastal.