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In my desperate hunt for a fast lens to go with my Pentax, I have found a bunch of fairly cheap f/2.0 50mm Pentax lenses. 30$! Great stuff... But! There is a catch. Radiation. How bad exactly are radioactive lenses? Will I have cancer? If so, will the cancer take better pictures than me? Will my cursed camera increase the cancer? Do I have any other sub-100$ options for a fast lens (any focal length is OK) in Pentax mount, considering I don't mind trolling ebay for hours?
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Sep 24, 2013 22:52
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| # ? May 9, 2024 12:11 |
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No Gravitas posted:In my desperate hunt for a fast lens to go with my Pentax, I have found a bunch of fairly cheap f/2.0 Pentax lenses. 30$! Great stuff... But! This random website says that levels measured closer than 3ft from the surface of the lens can read up to 10mR/hr. A chest x-ray is 10mR. I don't think I'd go for it if I had the choice, but I might just be a big baby.
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Sep 24, 2013 23:13
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I have this lens, cool.
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Sep 24, 2013 23:18
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Jellyko has a 50mm 1.4 but its miiiiiiiine if he ever responds to my email 
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Sep 24, 2013 23:21
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If the radiation doesn't fog your film it isn't a problem 
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Sep 24, 2013 23:24
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dakana posted:This random website says that levels measured closer than 3ft from the surface of the lens can read up to 10mR/hr. A chest x-ray is 10mR. Hahaha oh boy I have a pentax 50/1.4 in my camera bag at all times. Cancer, here I come!
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Sep 24, 2013 23:26
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No Gravitas posted:Radiation. Honestly I'm disappointed my big Tak 500mm doesn't show up on that list. nielsm posted:If the radiation doesn't fog your film it isn't a problem
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Sep 24, 2013 23:35
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dakana posted:This random website says that levels measured closer than 3ft from the surface of the lens can read up to 10mR/hr. A chest x-ray is 10mR. That figure sounds really, really, friggin' high. Thorium in equilibrium with its daughter products has an activity of 8000 Bq/g, 8000 Bq is about how radioactive a typical photographer is, just from the carbon-14 and potassium-40 in his body. And thorium's decay chain is primarily alpha, with a few betas on its way down to turning into lead-208, so there's no way you'd be dosed with even a fraction of the 10mR/hr that page claims can be measured. I think this is a better estimate: quote:Measurements have indicated that the exposure rate at a depth of 10 cm in the body of an individual carrying a camera containing 0.36 uCi of thorium would be approximately 0.01 mrem/hr. Based on this value, NUREG-1717 calculated that a serious photographer might receive an annual exposure of 2 mrem. This assumed that the photographer carried the camera 30 days per year and for 6 hours per day. They also estimated an exposure of 0.7 mrem per year for an average photographer. If the camera lens contained the maximum permitted concentration of thorium (30%), NUREG-1717 estimated that the aforementioned annual doses could triple. So to get the equivalent of a single chest x-ray (10mrem), you'd need to carry the camera for 6 hours per day for 150 days.
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Sep 25, 2013 00:42
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Thanks for that science. I thought it sounded really loving high, too, but didn't have the expertise to err on the side of possible cancer.
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Sep 25, 2013 01:03
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I'm still going to tell everyone I take a picture of with that lens that it's radioactive and I am shooting deadly energy rays at them.
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Sep 25, 2013 01:07
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I'm not much worried about radiation 10cm into the body. Skin cancer is a thing too, and I'd say there is more radiation 0.1 cm in...
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Sep 25, 2013 01:13
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No Gravitas posted:I'm not much worried about radiation 10cm into the body. Again, the decay-chain for thorium is mostly alphas with a couple of betas. Alphas don't even penetrate the skin. The only way a thorium lens would be a serious radiation concern is if you ground the thing up and snorted it. Seriously, carrying one of those lenses for a long time is like taking a cross-country flight in terms of additional exposure above background.
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Sep 25, 2013 01:38
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Phanatic posted:Again, the decay-chain for thorium is mostly alphas with a couple of betas. Alphas don't even penetrate the skin. The only way a thorium lens would be a serious radiation concern is if you ground the thing up and snorted it. Seriously, carrying one of those lenses for a long time is like taking a cross-country flight in terms of additional exposure above background. Great. I guess I will get myself a nice legacy 50mm then. Thanks!
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Sep 25, 2013 01:42
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You should hold a Geiger counter to your toilet bowl. You'll figure that that Thorium lens isn't that much of a problem anymore.
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Sep 25, 2013 01:45
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Combat Pretzel posted:You should hold a Geiger counter to your toilet bowl. Or your drywall, or your granite countertops, or a bunch of bananas...
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Sep 25, 2013 01:52
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No Gravitas posted:Great. I guess I will get myself a nice legacy 50mm then. I got a really cheap Pentax-a 50mm f2 from the local camera store to mess with and I am actually having a blast experimenting with it.
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Sep 25, 2013 01:59
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Redleg posted:I got a really cheap Pentax-a f2 from the local camera store to mess with and I am actually having a blast experimenting with it. It's not that kind of radioactive.
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Sep 25, 2013 02:33
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I'm pretty sure your 50/2 isn't radioactive anyways. I thought it was the older takumar branded lenses that were thorium doped.
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Sep 25, 2013 03:09
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I think pentax-a and later are non-rad. Anything not made in Japan also probably non-rad.
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Sep 25, 2013 03:17
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No Gravitas posted:Anything not made in Japan also probably non-rad. poo poo that's cold.
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Sep 25, 2013 03:24
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I still hope to get some photography superpowers from my Takumar 55 1.8.
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Sep 25, 2013 04:06
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All Takumars come with the same superpower: you look like a dork SD 095 16 by Execudork, on Flickr
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Sep 25, 2013 07:04
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Here's a pdf of training material for general radiation training we have to take here at work: http://esh-docdb.fnal.gov/cgi-bin/RetrieveFile?docid=304&version=1&filename=GERT.pdf I've found it useful to link other people to it who don't even work here as it demystifies a lot of what "radiation" actually means.
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Sep 25, 2013 15:49
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Print Exchange is live.
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Sep 26, 2013 04:37
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I have been considering grabbing a minolta slr for shooting 35mm. I have a rokkor 50mm f1.4 and a 28mm f2.8. I mainly use both lenses on m43 with an adapter. For 35mm film, I have been using a nikon n6006 which is a plastic brick and would like to replace it with something lighter, better in general, or less ugly. The Pentax ME Super is tempting, but the only k mount lens I have is a JC Penney 135mm f2.8. I am trying to reorganize/sell/trade my gear since I already have a Nikon 50mm f2 and a rokkor 50mm f1.4. I am leanning towards minolta slrs due to how cheap they are on keh also. The sr 202, xd-11 and some of the maxxums look interesting. Any recommendations?
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Sep 26, 2013 14:29
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Remember the Minolta lens mount changed between their manual focus and Maxxum cameras.
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Sep 26, 2013 16:31
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There's more information on it in the Sony thread, but yes, Minolta changed their lens mount when they went to autofocus. Maxxum cameras are autofocus and have what is now the Sony alpha mount, while older X-series manual-focus SLRs have what is variously refered to as the MD mount (or MC, or SR). I have an X-700 and I love it. Lenses and accessories are cheap because the mount is obsolete - adaptors exist for micro 4/3 (as you know) and for some other mounts but they're not widely used so demand for MD-mount glass is low. That keeps prices down, and Minolta made some rather nice stuff back in the day. Maxxum, because of modern compatibility with Sony DSLRs, has higher value but is still not really expensive. It hasn't been updated for a long time, but The Rokkor Files has some good information and reviews of bodies, lenses, and accessories. A 50mm/1.4 and a 28mm/2.8 is an excellent starting combination - pick up something longer for portraits or casual birding/wildlife/telelandscapes like a 135/3.5 or a 70-210/4 and you're laughing. As far as handling and basic use go, I find my ME Super and my X-700 are really similar - both can go Aperture Priority or Manual. The main difference is the little stuff, like how the shutter/mirror sounds, and how the shutter button feels. GWBBQ is selling an X-700 on page 161 of the buy/sell thread. I have dealt with him before, he's good. Make him a decent offer - he might be willing to not sell you the 50/1.4 mounted on his camera since you already have one. \/\/\/ As someone who owns 6 35mm film SLRs in 3.5 mounts (K and KAF count as 1.5), I must agree. ExecuDork fucked around with this message at 01:26 on Sep 27, 2013 |
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Sep 26, 2013 17:36
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Get both, duh.
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Sep 26, 2013 20:06
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I left batteries in my SB-600 for an extended period of time and when I pulled it out the other day the batteries had exploded and the flash no longer works even with fresh batteries. Anyone have any ideas on how to clean the battery corrosion from the flash in hopes of reviving it?
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Sep 28, 2013 00:17
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You've learned a $400 lesson: don't leave batteries in the flash. The acid has probably destroyed most of the terminals and associated wiring; cleaning it up isn't going to fix it.
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Sep 28, 2013 01:59
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Splinter posted:I left batteries in my SB-600 for an extended period of time and when I pulled it out the other day the batteries had exploded and the flash no longer works even with fresh batteries. Anyone have any ideas on how to clean the battery corrosion from the flash in hopes of reviving it? If you still have the batteries, and they're Duracell, Energizer, or Rayovac, you box the whole mess up and ship it to the battery manufacturer. They'll either fix it or replace it.
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Sep 28, 2013 02:50
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I was at Costco last week and saw they had an 8 pack of Eneloops for like $25 which is what kinda piqued my interest for flashes and triggers. Went back today to grab a couple packs, they were on coupon special for $20 but they were sold out. Asked someone to see if they had any more, or would be getting some in, turns out that they're a deleted item, at least for my Costco (I think they may do their ordering individually.) Guess I'll have to pick some up Sunday from another one off the freeway.
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Sep 28, 2013 03:00
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kefkafloyd posted:You've learned a $400 lesson: don't leave batteries in the flash.  Molten Llama posted:If you still have the batteries, and they're Duracell, Energizer, or Rayovac, you box the whole mess up and ship it to the battery manufacturer. They'll either fix it or replace it.
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Sep 28, 2013 03:28
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big scary monsters posted:Reading this just made me go check my flashes and welp Real solution: don't use alkaline batteries in your flash. They perform like poo poo and can also do stuff like that. NiMH 4 lyfe.
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Sep 28, 2013 06:05
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Using anything but high-quality rechargeable batteries in TYOOL 2013 is a silly and wasteful thing to do.
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Sep 28, 2013 15:28
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SoundMonkey posted:Real solution: don't use alkaline batteries in your flash. They perform like poo poo and can also do stuff like that. NiMH 4 lyfe. NiCad Krew reprezenting. Excuse me; after that burst of excitement, I have to lie down for 13 hours.
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Sep 28, 2013 21:24
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spog posted:NiCad Krew reprezenting. HEY MAN NiMH CREW CAN KEEP GOING FULL BLAST AND IT'S LIKE THE PARTY'S NEVER GOING TO ST- and now I'm unconscious.
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Sep 28, 2013 21:47
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ITT we roleplay discharge curves of various battery chemistries I guess.
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Sep 28, 2013 21:47
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Li+ in the house and OHH poo poo
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Sep 28, 2013 21:52
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| # ? May 9, 2024 12:11 |
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Hi, I'm your friend the lead-acid battery. I can party hard and party long, but I'm kinda gassy and if you don't maintain our relationship you'll never see me again.
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Sep 28, 2013 21:55
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