Follow Slashdot blog updates by subscribing to our blog RSS feed


Forgot your password?

Comment My experience in a Faraday cage (Score 2) 123

I was wondering if it maybe actually lends credence to people who claim they have allergies to various types of EM.

I was wondering the same thing. Last year I was involved in the construction of a large (4 meter cube) copper-screened Faraday cage for 100Kv partial discharge testing. When we buttoned it up, I went inside and closed the door. It was oddly quiet - even though it was simply screen. At the time, I wondered if there was something to the idea that our brain was susceptible to RF energy. It was strangely peaceful and enjoyable.

Comment Re:Action Required !! (Score 1) 382

If this is actually a credible report, then the U.S. government needs to stop funding the rebuilding/construction of areas that are CURRENTLY under sea level like New Orleans and the dikes and berms around it.

New Orleans was built on the high ground. But over time, parts of it slowly sank into the soft marshland underneath. There is no way they will abandon it. It's cheaper to continue to keep the water out. And it is mostly state and local money being spent, so let the locals vote with their pocketbook. I'm glad, because it is indeed a very special place.

Comment Re: lightning strike (Score 5, Insightful) 141

Bullshit. I used to design high voltage connections, and tested using a 300kV impulse generator. I've seen a lot of crazy stuff analyzing field failures. You can greatly reduce the risk, but you cannot remove all risk in an above ground facility, as a practical matter.

I do see lots of silly stuff done, based on myth and lack of knowledge.

Comment Utilities use Aluminum (Score 1) 288

Tin, nickel, gold, copper, steel... what haven't I seen used for connectors? Aluminum, that's about it. I think we all know why, but the sparks that shot out of the outlets in the mobile home in which I spent many of my formative years due to oxidation of the aluminum wiring are a big clue if anyone doesn't

Electric Power Utilities are heavy users of tin-plated aluminum connectors. They are normally used with aluminum cable, so you don't have fewer issues with thermal expansion, etc.

Using aluminum cable with copper connectors will generally result in cold-flow degradation of the connection, leading to overheating and fire.

Comment Re:The content of this article was lost in the noi (Score 1) 422

What technical reason would cause photographes to prefer mirror slap over the near-silent operation of a mirrorless?

My DSLR's are very well developed for very fast focus in very low light ( Nikon D700, D800). The optical viewfinder has zero lag, and works under all light conditions.

My mirrorless cameras (Nikon V1, Sony A6000) have electronic viewfinders (EVF) that have a lot of lag in dark conditions, making the camera almost useless at times. The Nikon V1 has the best on-sensor AF I've seen, and is the closest to a DSLR of any mirrorless camera. But it and the Sony A6000 simply struggle under low light conditions.

EVF's are fantastic for video, and (with "focus peaking") great for use with manual focus lenses. DSLR optical viewfinders are blind when shooting video. But EVFs are not up to the level of a DSLR for stills. That's why I shoot both.

Comment DOF is optical, has nothing to do with sensor size (Score 1) 422

Your forgetting that DOF is dependent not only on the lens, but also sensor size

This is not correct. DOF is dependent on the optics, and has nothing to do with sensor size.

The source of this commonly shared myth is the association of smaller sensors with shorter focal length lenses. It is the shorter lens that increases DOF, not the sensor.

Slashdot Top Deals

Dealing with the problem of pure staff accumulation, all our researches ... point to an average increase of 5.75% per year. -- C.N. Parkinson