Wikipedia:Reference desk/Archives/Miscellaneous/2017 March 19

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March 19

Why aren't talk pages for general discussion

of the topic?32ieww (talk) 01:53, 19 March 2017 (UTC)

Because idle talk is not encouraged at Wikipedia. If you want to talk about something, the rest of the internet is FILLED with places where you can go and chat with random strangers about anything. The purpose of the talk pages at Wikipedia is to discuss improvements to Wikipedia articles and nothing else. Because that's why Wikipedia exists, to be an encyclopedia. If you're not particularly interested in improving the encyclopedia, please leave the talk pages for those people who are. --Jayron32 02:18, 19 March 2017 (UTC)

WP:NOTAFORUM μηδείς (talk) 02:49, 19 March 2017 (UTC)

Obviously, you have to engage the subject to some extent if you're talking about changes to a given article. But it should be about the article. For example, if you say on Suzie Floozy's talk page that she's promiscuous, that's idle chatter (and also a BLP violation). But if you say you have sources on her many marriages, that's about the article. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:20, 19 March 2017 (UTC)

I always knew you were an anti-Floozian! In any case, policy Q's don't belong here. The OP needs to read WP:HELPDESK. or WP:NOTAFORUM and then check one of the policy based/new editor spaces like the WP:TEAHOUSE. We are somewhat misnamed in that we deal with references, not how to use them. μηδείς (talk) 16:58, 19 March 2017 (UTC)

I suspect the OP is talking about this, which strikes me as being a bit nannyistic on the part of the other user. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:45, 19 March 2017 (UTC)

Maximum Safe Load for a Wall Shelf

I have attached a shelf to my wall to hold electronic equipment, such as my oscilloscope and desktop power supply. It is 55" long, and attached to 2 studs, each with a brace with 2 10 mm screws. Is there a rule of thumb for determining how much equipment I can safely store on this shelf without risking it pulling free from the wall? OldTimeNESter (talk) 12:48, 19 March 2017 (UTC)

Too many variables. The weight of the shelf is more significant than the length, the type of wood used for the studs will determine how well the screws hold - as will the thickness and thread of the screws. How things are placed on the shelf is also an issue - weight towards the front of the shelf will exert more leverage than weight near to the wall. My one immediate reaction to your description is that 10mm screws sound very short for what you are doing. Wymspen (talk) 13:06, 19 March 2017 (UTC)

Yes, I wouldn't trust valuable equipment to a shelf supported by such short screws. I tend to use three times that length to support anything more than a kilogram or so. Is the wall made from something strong such as brick or stone? If so, then I would drill into that and maybe use something like rawlbolts (I'm sure you have something similar in the USA), or if you have only studs then I'd find some more and put in some extra screws. Dbfirs 13:52, 19 March 2017 (UTC)

(edit conflict)At a local street market some traders fashioned a canopy out of wood, which they nailed to a wall. They and the public would gather under it to do business. At 5:30 on a Saturday evening, just after the gaff had closed for the week, there was an almighty rending sound and the canopy crashed to the pavement. I'm no handyperson but I would have thought it would have been safer to construct your shelf using what I believe are known as "angle brackets". 81.129.13.243 (talk) 14:01, 19 March 2017 (UTC)

Oh, I thought that was what OldTimeNESter had used (screwed in to the Wall studs), but I agree that the larger the better, up to the width of the shelf. Dbfirs 14:07, 19 March 2017 (UTC)

If there is drywall on the wall, 10 mm screws are not even long enough to penetrate the drywall and reach the stud. A screw embedded in nothing but drywall has very little strength and can easily pull out of the drywall. The screws should be long enough to reach through the drywall and penetrate the stud by at least 15 mm or so. CodeTalker (talk) 14:43, 19 March 2017 (UTC)

• Are you West of Iceland? If so, it's not safe to carry any weight on a wall of typical US construction.

There are several aspects to this: shelf strength, strength of the attachment to the wall, strength of the wall. If you're US stud & drywall construction, or UK dry lined walls, then a specialist plasterboard (drywall) wallplug can attach securely to the plasterboard with a load up to the local bending strength of that plasterboard - which isn't much. A picture, a clock, but doubtfully a plant holder (I've seen too many pull out when the plant grows) and certainly not a loudspeaker or bookshelf. A non-specialist wallplug will carry the load in no more than an inch wide disc of plasterboard, and that's barely enough for a photo frame.

If the wall has wooden studding, and if the shelf attaches reliably to the studding (you hit the middle of the studs) then it's rather stronger - but still not strong. Enough for a loudspeaker, or for a decorative bookshelf for people who don't read, but not for a real bookshelf. You can use the Sagulator to play around with wood strengths.

IMHO, just don't use cantilevered shelves. Supporting them with uprights on their front edge is much cheaper. As usual, a compressive load in an upright is cheaper to absorb than the bending loads of a cantilever. You can cantilever shelves on double-hooked steel adjustable shelf brackets, but they costs more than cheap wood uprights at the front. One wall of my workshop shelves are like that, and I do store anvils on it, but those are a strong shelving system, screwed into a concrete block wall on long screws and plugs. Andy Dingley (talk) 13:12, 20 March 2017 (UTC)

What film format is this?

[1] Given the peculiar length of the boxes, I first thought it was 120 film, but the boxes state "400 film", obviously not referring to ASA. So, what is it? There is no "400 film" format on Wikipedia so far, be it as a standalone article or as part of the table found at Film format. The seller claims it would be regular 135 film, but as said, both the length of the boxes as well as the odd label on the box make me doubt that's what it is. --2003:71:4E33:E528:30F1:CC93:C64D:C3F7 (talk) 17:48, 19 March 2017 (UTC)

Why do you say it's not referring to ASA? The chart in our article lists these films as ASA 400 in the 1960-1987 ASA scale: Kodak T-Max (TMY), Kodak Tri-X 400, Ilford HP5+, Fujifilm Superia X-tra 400, Fujichrome Provia 400X, Fomapan/Arista 400. The handwritten note in your photo says "400 ISO", which is consistent with this. CodeTalker (talk) 18:10, 19 March 2017 (UTC)

Because a.) the peculiar box size (it's guaranteed to not be 135 film with such an odd box), b.) the box doesn't read any standard film format like 135 or 120 anywhere on the box, c.) the "400 film" label is where any standard Kodak film box usually states "135 film" or "120 film" in reference not to speed but to format aka size, and d.) the film I linked is not on your list. Oh, and e.), you've accidentally linked to a disambig page. The handwritten note is what the seller *CLAIMS*, but especially the box size makes the claim highly unlikely. It's not that I doubt that 400 ASA film exists, it's just that the seller is obviously mistaking a format for a film speed. --2003:71:4E33:E528:30F1:CC93:C64D:C3F7 (talk) 18:18, 19 March 2017 (UTC)

We cannot answer questions on behalf of ebay sellers. Do not buy if you don't trust the advertisement. Jahoe (talk) 18:28, 19 March 2017 (UTC)

Also you could Google "kodak 400 film" and select images. Seems like it's their trademark for 35mm 400 iso. To buy or not to buy remains up yo you of course. ;)

Also note that ebay routinely converts images to 4:3 aspect ratio. Anyway, ask the seller, only he can give you a guarantee.

Jahoe (talk) 18:39, 19 March 2017 (UTC)

I'm not looking for a guarantee and I don't wanna buy the film, I just feel that Wikipedia is missing an entry at Film format. The image displayed is not 4:3, it's 16:9, and the boxes are much too wide for 135 film, so if anything, it'd have to be a 4:3 image that's been re-sized to 16:9, not the other way around. Plus, the stack of notes looks like the aspect ratio is correct. If you just google for kodak 400 film, you're bound to get results for 400 ASA films because films with that speed do exist, but it doesn't mean that "Kodak markets 400 ASA films as '400 film' ". --2003:71:4E33:E528:30F1:CC93:C64D:C3F7 (talk) 18:59, 19 March 2017 (UTC)

Here's another ad by the same seller: [2] Most of the boxes on that photo have a correct size for 135mm (with a few Holga films in 120 format at the top left), only at the bottom right is another box with that odd size, so this is proof that the aspect ratio is not at fault. Moreover, the seller claims that all the BW400CN boxes in the photo would be 35mm, so it seems he himself doesn't seem to be able to tell the difference. It can't even be two films in one box, as although the box is too wide for 135mm, it's not wide *ENOUGH* to carry two 135 cannisters next to each other. --2003:71:4E33:E528:30F1:CC93:C64D:C3F7 (talk) 19:10, 19 March 2017 (UTC)

I notice the boxes say in the upper left corner they contain three rolls, which would explain why the shape of the box isn't right for a single roll. Of course whether to buy it is entirely up to you. Jc3s5h (talk) 19:11, 19 March 2017 (UTC)

Oh, so it's 3 rolls per pack! Thank you. --2003:71:4E33:E528:30F1:CC93:C64D:C3F7 (talk) 19:13, 19 March 2017 (UTC)

• In one of the photos, you can see that the two packs with the word Professional in the name of the film reassure the buyer that they are to "Use in any 35 mm camera; process at any photofinisher". So that should settle the format question. What I want to know is why anyone would buy rolls of film that expired in 2006–2010. Or could the seller just be being wildly optimistic? --76.71.6.254 (talk) 19:40, 19 March 2017 (UTC)

The table at Film speed confirms that ISO 400 is the same as 400 ASA or DIN 27 or GHOST 350. The text on the film packaging "Use in any 35 mm camera... and "24 exposure" should be noticed. The condition of outdated film stock depends on how it has been preserved; ideally kept in sealed cans (against humidity) at -18°C (0°F) or lower. Blooteuth (talk) 23:11, 19 March 2017 (UTC)

Back in the 1960s and 70s, it used to be common for photography shops to have a basket of expired films at reduced prices. For those on a tight budget, it was worth a gamble. 10 years is a bit of a stretch though. Alansplodge (talk) 01:19, 20 March 2017 (UTC)

Yes I don't know why there's so much doubt over this. The boxes easily look like they could store 3 35mm film canisters. And other than the fact the photos clearly say 3 rolls, the seller is selling 18 rolls but only has 6 boxes. And ISO 400 (although not so much 400 ISO) is the standard way to refer to the film in a lot of places. It seems even clearer with the other eBay listing. While in that case it doesn't seem to say on the photo how many rolls are in that big box (that I can see), you can see there are 72 exposures in that one large box and 24 in the smaller ones. Further the seller says there are 7 but there are only 4 boxes plus the big one. Most telling of all, if you consider parallax etc, even if you don't know the size of a 35 mm film canister it's not that hard to work out that 3 of them would fit in that big packet (obviously stacked vertically rather than horizontallly as the single packets are). Nil Einne (talk) 06:55, 20 March 2017 (UTC)

It's hardly a mystery. The Kodak HD stuff is available new here; the 400UC stuff is here. --jpgordon^{𝄢𝄆 𝄐𝄇} 05:08, 21 March 2017 (UTC)