I have a question which I hope some of you on here will be able to answer.
I have another of my late fathers Leica lenses, a LEICA SUMMICRON 50mm f/2 , which will fit on my Sony Alpha 6000 with an adapter.
I did a search on the lens and have discovered that it is Radioactive (it’s early serial numbers indicates this).
KenRockwell.com states the following … “The first year or so of production (below about serial number 1,050,000) emits about 20 microSieverts per hour at the front of the lens (0.2 mR/hr or 2 µSv/hr from rear of lens), while lenses made from 1956-on are inert”
So two questions:
Is the radioactivity likely to effect my camera sensor or any other bit of the camera?
Is it safe for me to use? I sort of assume “yes”, but various google searches get quite technical and confusing…
In practice everything made after WWII is radioactive. I read that some sensors in a space telescope have been built using steel recovered from a WWII battleship to make sure it is completely inert.
See: Orders of magnitude (radiation) - Wikipedia. The chart says USA NRC public area exposure limit (if exposed for a day). Hourly, it is equivalent to at least twice the cosmic rays you might get from a commercial flight (depending on where you are). Some people worry about their cameras when flying. Some don’t.
I guess the key is that radioactive elements have a half life. Sometimes their products are more dangerous than the original substance. Maybe use a Geiger counter to see how much it actually is for a given distance. It is entirely possible that the radiation is low and short distance, in which case, you are in luck. I would store the lens separately from the camera if you are concerned.
The radioactivity actually improves image quality as I recall (been awhile since I read up on why they made radioactive lenses, but do recall reading this). How is a matter of science. Not sure how such lenses affect modern day cmos sensors, though.
Yellowing. It can be reverted by exposing to sun or UV light though.
As regards radioactivity, just measure it with a geiger counter with seivert values following the table above.
Yes, it can be a dangerously radioactive article, if it really is - before you measure it, just avoid exposure to it for a long time, e.g. don’t hold it against your body for long. Even though, the dose you mention is detectable, it’s quite negligent.
солнечная радиация и космические лучи – от 0.300 миллизивертов в год
sunlight radiation and space radiation - from 0.300 milisieverts per year. So it produces in an hour from just under the year of sun radiation to a natural level of 0.2 micro sieverts.
The radioactivity doesn’t improve image quality, the thorium improves the optical properties of the glass which can then be used to produce a better-performing lens.
As an aside, @Phil_Howcroft, I did notice that one radioactive lens I have doesn’t have fungus whereas the other two lenses that it was stored with have noticeable fungus. Maybe the radioactivity itself is helpful in that way.
I suppose I could asks myself why do I want to put a 60 odd year old 50mm lens on my Sony Alpha 6000 when I have a Sony 50mm prime lens? The answer is it is probably in homage to my Dad and his Leica and also because I can, albeit the “I can” bit is complicated by the radioactivity.
General consensus is don’t worry, but I an a worrier by nature. The more you read the more you get confused !
Just another way of saying you’ll get an improved images using radioactive glass, CarVac. As for image quality, there’s obviously other factors, but without a good lens, you will get a bad result from the get go.
We are talking alpha-radiation here. You can block that with a newspaper or a base-cap. No alpha-radiation gets through the polycarbonate or metal of a camera housing. You’re totally safe!
Gamma-rays are a tad more powerful and highly devastating on our bodies in general and genome in particular, but there’s no gamma-radiation involved in lens-making.
@beachbum My point earlier was that the thorium could break down into more radioactive substances like radium, which emits gamma radiation. Even then, the gamma radiation might not necessarily mean more defective pixels, only a higher chance for them to occur. Even then, for a camera with such a high pixel count, several bad pixels won’t be the end of the world .
Thanks Stefan.
It came as a shock to me when I did a Google on the lens and in two clicks I discovered it was radioactive .
This thread and your reply gives me reassurance to use it .
Cheers
Green/yellow antique glass plates and glasses had radioactive levels associated with them - I believe uranium was used to impart the color. We had come across some of them at an auction, but looking on the net for info later, we discovered that there would be minimal risk - unless you carried them around with you all day. So, I’d be inclined to use on birthdays.
I have quite number of old lenses and I like most of them. And it can produce quite nice or interesting images.
I have Summicron-R 50mm f/2 lens and I really like the lens so you might like that lens, too…
Once you took the photo, you probably needed to do the simple tweaking like increase contrast value and adjust white balance value–I’m using Sony a7 and I don’t think Sony a7 can correctly adjust white balance value especially old lens.
I don’t think my Summicron-R 50mm f/2 lens needed increase contrast value but many of my other old lens–include Elmar 90mm f/4 lens, needed it.
I’d like to say that old lens can produce very comparable image than Sony 50mm prime lens. But that’s probably my liking.
Last year, I bought yellowed(in optics) Takumar 50mm f/1.4 lens and I did exposure to the sun for two weeks(two to four hours)–de-yellowed it–probably need more exposure to the sun but it wasn’t much so I am just using with slight–yellowed inner optic.
I think you don’t have to worry about much–Takumar 50mm f/1.4 lens is quite famous lens and many and many people still using this radioactive lens.
I still haven’t used the lens. Not because of the radioactivity but because I’ve had several other time consuming photo projects opportunities over the last few weeks
Thanks for the advice and guidance. I also contacted Leica UK and asked them for an opinion and they confirmed what everyone else had said i.e. the amount of radiation emitted was minimal and no different to what one would find in everyday living.
So I’ve finally used the lens on my Sony A6000. I took a few images last night and have uploaded the images for you to take a look .
The portraits are me (took by my wife following my instructions) and the RAW files were edited in Rawtherapee / GIMP.
The three lads sat on a bench in the field were also edited via a RAW file in Rawtherapee / GIMP
The other shots, St. Mary’s Church in Arnold, The signpost and my wife walking our dog are from jpeg’s edited in GIMP
I think the conclusion is that the SUMMICRON 50mm f/2, manufactured in 1953 is a pretty good bit of glass
It seemed to struggle a bit with direct sunlight, but then most lenses do.
Jolly fine result with that lens!
I believe that you will really enjoy it during the years.
Putting old (manual) lenses onto a modern (digital) camera is great fun.
One of my personal favourites is the Industar-61L/Z, chiefly because it
has such a l-o-n-g and smooth focusing helicoid. Here is a description of
when Alfred measured its radioactivity: http://www.cameras.alfredklomp.com/fed5/radiation/
.
