I just took delivery of a pair of Bloc Mask MK14 Photochromic Silver Mirror/Cat 2-3 goggles.
I put them on in the shed then stepped out into the blinding sunlight and nothing changed, several times. I've seen people with reactalite sunglasses and you can definitely tell the difference, but with these goggles there's no change. I certainly wouldn't like to be up a sunny mountain with only these to protect my eyes.
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
I had the Bolle Modulator and they would definitely switch, but it wasnt instant. I also found that they were in a middle ground, so if it was super bright then they wouldn't be as good as a dark lens, and if it was really flat they weren't as good as a low light lens. But as a general all rounder I liked them.
I much prefer my Smith I/OX with a dark lens and a light lens. Most days you can pick a lens and stick with it, but switching them takes less than a minute.
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
<shrug> the Salomon ones work great in snowy mountains, that's all I know.
I don't like to stop during runs, so mucking around with multiple lenses doesn't work for me.
I just took delivery of a pair of Bloc Mask MK14 Photochromic Silver Mirror/Cat 2-3 goggles.
I put them on in the shed then stepped out into the blinding sunlight and nothing changed, several times. I've seen people with reactalite sunglasses and you can definitely tell the difference, but with these goggles there's no change. I certainly wouldn't like to be up a sunny mountain with only these to protect my eyes.
Could you see okay out of them? I have bought meself some julbo zebra photochromic things, no chance to test for real, yet, but have done a bit of walking round from dark to light. The goggles don't change that I can tell, they're mirrored so how would I know?, i can see through them from dark to light so am hoping they'll work in the wild!?
Just tried again - it's a bit dull here, no sun. Looking at the bulb of the lamp, no glare, not blinding. Turn lamp off, slight delay then able to see fine. Is that not what they're supposed to do?
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
@marodo2712, you may need more extreme lighting conditions in order to fully observe, or recognise the change.
The "photochromic" process doesn't respond by changing density ( neutral reduction of light) but by shifting colour, designated by the "chromic" description. Although this is in response to light level.
A scenario in the mountains is that as the light level climbs it ends up more blue, going from something like 5000 kelvin ( normal daylight colour temperature) through 7000 and approaching 10,000 at extremes. If the lenses respond with yellow ( dark yellow is brown as we see in many sunglasses) this will effectively screen significant amounts of the blue component in high light levels, and ultimately give that category shift they give in their technical performance.
In short you're probably going to need a very high "blue " day to observe the full effect. But even then your eyes have a hugely ability to adjust to the colour in front of them, making your brain see a normal scene.
You'd probably observe them most strikingly by looking at Blue ski until your eyes normalise through the lens, then taking them off, you should immediately see the scene as bright high level blue until your eyes again normalise their signal to your brain.
Julbo are good - i'm still using Smith though. Red Sensor in the past, now the newer Rose chromapop version photochromic i think it is. Works great from skiing under floodlights at night to sunny days. (All day mountaineering on glaciers etc would be another matter of course...).
Then you can post your own questions or snow reports...
Then you can post your own questions or snow reports...
@coops1967, Chromapop aren’t photochromic, afaik.
After all it is free
After all it is free
under a new name wrote:
@coops1967, Chromapop aren’t photochromic, afaik.
As stated, the designation is saying high contrast colour really, in a marketing way
Chroma = Colour in image terms. They just use pop (slang for raised contrast and probably come from film imaging, example " I have my Ektachromes pushed one stop to give them more pop") as part of imaging description. Historic reference there
The pop is achieved just by using very thin coating on the lens surface to preserve and enhance the colour purity ( as opposed to older goggle lens of died through plastic) and very similar to camera lens coatings.
The industry has got a bit exited about "Chroma" though and generally just hose down their products with it as a current buzz word.
Nothing wrong with Chromapop lenses though, they do a very good job. Just the promotion of the different types seek to get you buying their product, obviously.
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I've had a couple of pairs of Bollé photochromatics and they suit me. Ok not as effective as separate lenses but good enough. Make sure you get ones with lenses covering ranges 1 - 3, some are only 1 - 2.
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@ski3, I was under the impression thatphotochromic lenses work by actually darkening on exposure to UV (i.e. won't darken with house lights) and not by switching frequency filtration (WP agrees with me) whereas the Smith Chromapop lenses work by selectively not filtering the frequencies that are likely to be most helpful, e.g. while skiing on a sunny day so increasing perceived contrast.
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snowHeads are a friendly bunch.
Well "chroma" is a common term in video technology, but it's a marketing term here. I could find nothing looking even slightly technical to describe what this actually means or does. I could find no patent ("pending" or otherwise) relating to it. I'm not saying that the lenses are no use (I've never tried them), just that the name appears to be a marketing concept rather than a technology. I would guess that goggle companies probably employ more people to think up this type of branding than they do to research the optical properties of lenses. I'm making no comment on the lenses themselves, just the attempt to fool people with fake science.
"Photochromic" and "polarised" are real technologies which actually work.
And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
@under a new name, agree that it's stated, it's also mitigated in that text by saying "most commonly UV" it's certainly more of a rabbit Warren of a subject than the initial views gives I feel.
@philwig, yes, Chroma just means colour and not in any way protected. In both video and photography it just refers to changes in colour as opposed to density ( which is neutral) so colour change / manipulation instead of darker / lighter.
Photochromic, could be used to describe changes in response to Chroma input by shifting density (as the wp text) or Chroma change in response to relative light level.
They definitely seem to respond as they state in shifting from cat to cat, it's trying to see what they respond to from the original op question.
So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much
So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much
@ski3, a good example of WP being only a good step for a hint. Interesting site that. Does lower frequency light than UV carry enough energy to effect the reaction, typically?
You know it makes sense.
You know it makes sense.
under a new name wrote:
@coops1967, Chromapop aren’t photochromic, afaik.
Some are.
Mine was for the I/O7 - the "ChromaPop I/O7 / Photochromic Rose 30-50% VLT"...
Link direct to a current smith option doesn't want to work, but go to smithoptics.com and you can choose the 'lens technology' to narrow the displayed choices down to the photochromic options
They're very good, highly recommended (and non fogging).
Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
under a new name wrote:
@ski3, a good example of WP being only a good step for a hint. Interesting site that. Does lower frequency light than UV carry enough energy to effect the reaction, typically?
I don't know, typically the further from scource you get the less energy it can impart generally.
I've got maybe an obscure link, although related to this, in photography. One area of setting high power lamp scource in machinery the tungsten bulbs are placed in front of individual parabolic reflectors, the purpose of which is to capture as much light as possible and pass it back past the bulb filaments toward a condensing lens today output. If you got the physical position of the lamps wrong it would focus the energy such that it melts, and subsequently explodes the bulb envelope.
Another type using "cold mirrors " bounced the visible spectrum of a mirror specifically constructed to pass IR component principally, then blow that heated airport away with a fan from the back of the mirror. There is also warm up routines as the light transmitted changes with temperature of components, so no point in calibration until stability achieved.
It's not limited to the above as so many aspects deal with this topic, many are dealing with imperfection in response materials to best manipulate the outcome.
At the other end I've taken endless number of films skiing to capture typical high mountain scenes to use in optimising machine setup to give representative output.
It's generally pretty blue dominated up there, but high levels of light when screened by cloud I believe give significant reduction of UV. Obviously highest UV is complete cloudless ski which is why high cat rating is desirable.
Overall a fascinating subject, and all the better when you're able to get something that really suits your eyes and does a good job for you.
Poster: A snowHead
Poster: A snowHead
For the "digital era babies" Chrome has been used for along time in describing colour photography.
As above, even a song about it and it's depiction of life.
Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
@coops1967, oooh. Didn't know they existed. Nice.
@ski3, yes, very interesting. Oddly, "Optics" was my second least favourite course at Uni. Fourier transforms. Ugh.
Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
A questions for the more knowledgeable, just out of interest ...
Are the phtoochromic lenses discussed here like my spectacle photochromics? I ask because while my photochromics are good, I still have clear spec's and prescription sunglasses because:
Photohromics react faster in cold than in summer, so in summer, prescription sunglasses are better, if tedious to carry and swap.
They don't react fast enough to deal with moving from very bright sunlight to very dark shade. With goggles and plain glasses, I can just quickly raise the goggles. With photochromics I'm skiing blind for at least a few minutes (which is not good).
I also read somewhere that you don't want your glasses to darken the view too much because, especially at altitude, your pupils will open wide and still be letting in damaging UV, even if they're no longer being scorched by high levels of light.
... With photochromics I'm skiing blind for at least a few minutes (which is not good). ...you don't want your glasses to darken the view too much because, especially at altitude, your pupils will open wide and still be letting in damaging UV, even if they're no longer being scorched by high levels of light.
(1) For me, the whole point about using photochromic goggles is (a) so I can ride into and out of the forest without stopping; and (b) so I don't need two pairs or two lenses. For me, then, precisely what you're asking works perfectly and I do not ride blind (especially through forests at speed).
(2) I think you will likely find that the UV absorption is performed by the base lens material. You should not have UV transmission, hence your point is not relevant. I can't prove this, however I have some evidence from surfing... if I surf for a few weeks without eye protection, my near vision goes. The UK's most expensive eye surgeon tells me this is because the UV essentially cooks your lens, taking you quicker towards cataracts and generally doing damage there. I use photochromic swim goggles I don't suffer from this at all.
I would assume that different manufacturers' gear may well behave a bit differently. You can compare specifications, but they're not all consistently described and things like "response time" aren't generally published. I think in practice you have to take a chance and try some.
Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
Mine is anecdotal in answer too, but endorses @philwig, point about UV.
Most of the materials used will screen the UV effectively so that it won't reach the eye directly through the lens. So anything that is appropriately constructed / rated should negate UV concerns.
Camera UV filters are essential just clear glass, usually multicoated for transmission performance so that they don't degrade the image, much.
But the risk with UV is that it gets round the lens from incidentally reflected light, hence the total exclusion in things like sunbed eye protection as an example.
Goggles obviously too, and the wrap around sunglasses trying to perform the same level in excluding extraneous light. The swimming type of course too in that they are totally covering off any ingress.
I received three more pairs of Photochromic goggles yesterday:
Cairn Funk otg cat 1 to 3 for kids.
Smith chromaPop rose flash cat 1 to 2.
Cebe razor Vario orange cat 2 to 3.
I placed them, and the Blocs, on the garden table (covered), then, in bright sunlight, removed the cover and sat and watched.
Nothing happened, no lenses darkened or changed colour.
Is it just a con?
Can anyone provide actual photographic evidence of Photochromic goggles getting darker?
Then you can post your own questions or snow reports...
Then you can post your own questions or snow reports...
@marodo2712, I'd be interested in this too, for various reasons I can't wear contacts and have historically worn prescription inserts in my goggles. I have however changed my helmet this year and gone for an integrated visor to go over my normal spectacles. I opted for a photochromic salomon visor and tried the same test as yourself but also failed to see any difference in the darkness etc of the lens
After all it is free
After all it is free
As I understand it, Photochromic lenses darken due to UV radiation - which is at a much higher level in the Alps, so the effect is much more pronounced when skiing. Remember, UV is weaker in Winter - so your experiment should be done on a hot Summer's day.
As you don't really want Snow Goggles to go completely clear, there is a certain tint "built in".
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Visible light transmission (VLT) seems to be key...
When really to cover all conditions in the mountains you probably need something more.... such as the Zebra's listed above?
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Ski the Net with snowHeads
The eye will often give a good assessment in a comparative test, but absolute could mask what you see as it's so competent at adjustment to varied light levels.
Measurement of transmission, probably best with lux setting if you're not familiar with photography / sensitometry readings should give you some more absolute readings to compare from through lens measurements.
UV content rises as you increase altitude simply because you have less atmosphere between you and the sun. Cloud will always mitigate absolute UV as I understand it.
VLT, obviously visible spectrum, should exclude all UV as they couldn't sell the lenses as certified if they didn't. Whether IR gets through or not they don't say. It's present to varied degrees but most camera imaging chips are screened for it ( the pixels will read both IR and UV) so the app measurements should be just a straight read of VLT.
snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
When I wanted to see if the technology had changed since my last pair arrived, I just covered half the lens up and left the other half exposed.
That makes it trivial to demonstrate the effect, even in English November light through triple glazing.
It's possible that fake goggles exist along with bad experimental protocols. My goggles work fine.
Absolute Snow has a reference for most lenses, however it's not up to date.
They list Salomons at 14-47%, but Blue Tomato had them at 18-42%, with the extra low light lens at 53%.
I think these numbers are best used to compare lenses within a range; I'd not trust them much.
I use the Salomon S/Max Photos because I though they looked like the best available technically.
The Julbo specifications look great.
I've ridden with many people, sponsored and otherwise, and I've never come across anyone with photochomics who bitched about the speed or depth of the transition.
I suppose there's always someone, and for them other technologies may be more appropriate. That said, it's very rare to see people swap lenses in the back country.
In practice people use two-lens systems like people used to use two pairs of goggles: they put up with "the wrong lens" quite a bit of the time because of the hassle of changing.
--
As a one-time Spectrophotometer designer, you really need a UV/Vis Spectrophotometer, so you can profile a lens's properties across the frequency range
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