Best value for the least spent is what I was getting at.
If one reads the post as - best value for lens purchased? I would assume the OP is soliciting comments on lenses that any one here could shop for currently and purchase themselves, rather than the buy of a lifetime or something gifted.
Thanks for the explanation Donald, I'll give the EIR a go in the near future. So far I've shot it with a Wratten 12 filter on my LX and the images were way too blue so that's why I'm gonna try it with an orange filter.There is yellowing of the glass itself that occurs in thoriated elements -- it's apparently caused by the alpha particles knocking atoms out of their place in the glass. Fortunately, it's corrected by prolonged exposure to high levels of UV -- in the case of my own Super Takumar, I wrapped the back end of the lens in aluminum foil (to provide a reflective surface as well as protect the rear element) and left it on a windowsill that received partial day direct sun for, as I recall, about three weeks. The yellowing was greatly reduced. It has never had any visible effect on either B&W or color photographs -- in the case of B&W, it would at most act like a mild yellow filter, and for color, it would be easily corrected out during printing or scanning. I don't recall every shooting chromes with that lens, but those would tend to pick up a mild cast.
The lens is incased in metal on five sides. Put a metal cap on the front if you are worried.As I said, I understand people's opinion on radiation may be different, but I personally would rather avoid exposure as much as possible. I do own some radioactive lenses, therefore the less I own the better. Just wanted to clarify though, on a quick search, an Am-241 smoke detector appears to give a dose to a normal home owner of 10-50 nSv in a year. A single Yashica lens, at around 1 meter, and according to camerapedia, is 762 nSv in just one hour.
Quick edit: I just realised that is probably not fair to compare different radiation sources since they may decay differently etc. and the type of emmisions may be different. But as a biologist, I think people should be a bit more aware of trying to minimise radiation sources to the minimum when possible. There is a very good video on the topic on Simon's utak channel on youtube, nevertheless I don't think we should stray away from the topic of this post too much.
I picked up one of these recently for $30. It’s mounted to my N2000. Small world!
the N2000 is among the best street cameras.
Smoke detectors are in living areas and radiate into free space.
Hello, All,Every smoke detector I've opened (to replace batteries) had the americium alpha source about 80% encased in metal (needs to have air circulation through the sensor cell), with the remainder still inside the plastic housing of the alarm unit. That should amount to about 95% or higher shielding for alpha. Hence the exposure from one being comparable to background in a low-background region.
Exactly.Every smoke detector I've opened (to replace batteries) had the americium alpha source about 80% encased in metal (needs to have air circulation through the sensor cell), with the remainder still inside the plastic housing of the alarm unit. That should amount to about 95% or higher shielding for alpha. Hence the exposure from one being comparable to background in a low-background region.
Every smoke detector I've opened (to replace batteries) had the americium alpha source about 80% encased in metal (needs to have air circulation through the sensor cell), with the remainder still inside the plastic housing of the alarm unit. That should amount to about 95% or higher shielding for alpha. Hence the exposure from one being comparable to background in a low-background region.
It’s incredibly unlikely that you’ll have bad effects from smoke detectors. Though they work best in areas with with ventilation and that connect two or more rooms. So directly above you in a place where you spent much time may not be optimal, apart from having a cosmic chance of giving you any kind of health problems.ok please educate me. I have many smoke detectors all over the place, those things save lives and I have first hand experience. Can’t love those things enough.
There are 2 in my darkroom, one of them right near my forehead where I standat least 4 hours a day. Should I move it somewhere else?
And oooh! believe it or not, on my right side about 3 feet from my head at eye level there is a Aero-Ektar looking right at me, with its radioactive element. Haha this is crazy.
Speaking of which, the Aero-Ektar 178mm were widely available for 5-10$ some 10-15 years ago and before. I remember reading forums where that particular lens was despised... Now that was a bargain! I purchased my 2 copied in the 350$ range, which I do not consider a crazy deal, but a good deal nonetheless.
It’s incredibly unlikely that you’ll have bad effects from smoke detectors. Though they work best in areas with with ventilation and that connect two or more rooms. So directly above you in a place where you spent much time may not be optimal, apart from having a cosmic chance of giving you any kind of health problems.
Just turn the Ektar around or put a metal cap on it. Done.
Alpha and beta particles are stopped by very little material.
I have many smoke detectors all over the place, those things save lives and I have first hand experience. Can’t love those things enough.
There are 2 in my darkroom, one of them right near my forehead where I standat least 4 hours a day. Should I move it somewhere else?
And oooh! believe it or not, on my right side about 3 feet from my head at eye level there is a Aero-Ektar looking right at me, with its radioactive element. Haha this is crazy.
I picked up an old Vivitar 28-70 f3.5-f4.8 manual zoom (nikon ai mount) for a few bucks and found it to be pleasantly “glowy” wide open, but razor sharp stopped down even 1 stop, plus it’s tiny and very lightweight. Vivitar also made a 2x tele-macro converter that turned an olympus 50 1.8 into an even sharper 100mm macro, don’t ask me how, but it worked great.
I picked up an old Vivitar 28-70 f3.5-f4.8 manual zoom (nikon ai mount) for a few bucks and found it to be pleasantly “glowy” wide open, but razor sharp stopped down even 1 stop, plus it’s tiny and very lightweight. Vivitar also made a 2x tele-macro converter that turned an olympus 50 1.8 into an even sharper 100mm macro, don’t ask me how, but it worked great.
I picked up an old Vivitar 28-70 f3.5-f4.8 manual zoom (nikon ai mount) for a few bucks and found it to be pleasantly “glowy” wide open, but razor sharp stopped down even 1 stop, plus it’s tiny and very lightweight. Vivitar also made a 2x tele-macro converter that turned an olympus 50 1.8 into an even sharper 100mm macro, don’t ask me how, but it worked great.
What a beautiful negative or print. Well done. And even exposed on "useless" out of date film.Sample photograph made on Ilford FP4 (expired in 2008) with the Anastigmat mounted on my B&J Watson. Exposure was 1 second at f5.6
What a beautiful negative or print. Well done. And even exposed on "useless" out of date film.
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