OK, just got back from shooting a birthday party for some friends and i came across a scenario i've never experienced before - glasses with reactolite lenses.
Now i can shoot with glasses, and i had no choice but to shoot with a flash (it was indoors in a shaded room), but the reactolite's turned black every time the flash fired.
The only solution i could make work was to remove the glasses...
So, how do others deal with this issue?
i had no idea they reacted so fast :o
if i get permission to post a pic, then i'll give an example.
Believe me - i was just as surprised, but without time to post a thread asking for help ???
What was worse - 1/3 of the party had them >:(
they shouldn't have gone to specsavers ;D
I've not seen or experienced this personally, but I have heard that Reactolites are designed to protect the eyes by darkening quickly if the light level suddenly rises, then clearing more slowly as the light level drops. Judging by your post they obviously work!
(I can't think of any answer other than using flash at the minimum power necessary for the photography and setting the shutter speed at the highest the flash sync will allow.)
Quote from: alan1572 on August 21, 2010, 06:01:19 PM
i had no idea they reacted so fast :o
Um generally they don't. They also don't react to visible light at all - it's UV light that makes them change. Which is why they don't make great driving glasses - enough UV is filtered by the windscreen to make them slow to change.
I have some reactolites which are apparently the latest generation - every gen is faster than the last. I just ht them 4 times with full power from an SB900 at < 1 foot. No change whatsoever.
So....
1. Are you sure? Is this something you observed live or is it just on the pictures?
2. Can you show us a snap?
(http://cameracraniums.com/gallery/albums/userpics/normal_reactolite.jpg) (http://cameracraniums.com/gallery/albums/userpics/reactolite.jpg)
As you can see, one pair has tinted, the other hasn't. I realise that in this shot, the flash is direct at the subjects, but even a bounced flash was causing issues.
I was also of the opinion that they didn't darken up that quick, but it appears they may be getting just a little bit quicker nowadays...
Did you actually see them go dark or was it just in the picture? Did you see them not dark before?
I'm wondering if this is more to do with an anti reflective coat or weird polarisation effect than reactolites. Plus 1/3 of people at an event having reactolites is pretty unlikely.
I'll ask my optician next time I'm in but I seriously doubt they can change in a fraction of a second.
if seen side by side - these 2 pairs of glasses were the same as the pair on the right.
When the flash was used - those "reactolites" turned as the ones on the left.
Yes, they were reactolites because i asked each time i came across them.
Now, in respect of your suggestion that it might be some kind of coating - i'm fine with that - just so long as i know for future reference.
That is the purpose of this thread - to get a solution to the problem - or alert people to the fact that the problem exists...
Hmm then I'm stumped.
It's weird because
1. I've never seen this and I've taken lots of pics of people in glasses with flash
2. Reactolites seem to take about 20 seconds to change - this would have to be faster than 1/60
Best guess has to be that the glasses were in some way tinted and that the flash exposed this rather than caused it. Like you say it doesn't much matter what the exact cause was.
My guess would be that taking the flash out of the axis of the lens and reducing the apparent power (so it's only providing a stop or so of fill) will help. But it's only a guess.
Yes, got me stumped as well.... and I spent my entire working life life (34 years) making and glazing spectacle lenses. I'll take an sb800 to work tomorrow and have a play in the scrap box.
NB Reactolite is a brand name, a bit like "Hoover" and are a glass lenses. The vast majority of photochromic lenses are now "Plastic", usually cr39.... I'd give you the full name but it's been a long time since I last had to spell it!
I'll let you know how I get on.
Graham.
Jonathan & Graham,
i appreciate all of your suggestions and offers to test.
The reality is, i will not get this family together again for another shoot - they come from all over the country.
But in the even that i end up doing another shoot like this, i would like to think i don't have to resort to asking people to take there glasses off!
I now have to go and find some one with photochromatic lenses fitted to their glasses and see if i can re-create the effect.
Now i've finished training, i should hopefully have time to experiment...
I wonder if she has a special tint applied to her lenses, as some older people require these. :-\