physical – How long can I reasonably expect my external USB HDDs and memory sticks to last?

I have a number of external USB HDDs (nearly all of them 2.5″) in my fireproof safe. They are between 7 and 9 years old. (For a period of two years, I bought one almost every month until I had enough for me to feel as if it was not logically possible for all of them to die on me at the same time.)

There’s also a bunch of USB memsticks, not much younger than the HDDs.

I take them out on a rolling schedule and sync new data to a couple of them from my main computer, then put them back. It’s a chore, but I pride myself on not willingly uploading my data to some “cloud” storage. (One would have to be a fool to assume that they can’t, or won’t be able to later, break current encryption.)

For years now, I’ve had a nagging feeling in the back of my head that I should be replacing the old ones, or at least prepare a couple of new ones to take their place when they inevitably die on me.

Other than the purely practical problems of cost and getting them here (long story), it just feels weird to me. This might be a sign that I’m getting really old, but it feels like I just bought these disks. They certainly don’t feel almost a decade old! Furthermore, I’ve barely used them according to myself. They’ve mostly been resting in their cozy safe, only regularly getting any “action” in the form of I/O. It feels like I’ve not been “wearing and tearing” on them nearly as much as would be the case if I, for example, was some kind of GoPro action adventurer who has a backpack of HDDs with him on his wild trips into the mountains, where he constantly transfers large video files and exposes them to heavy impacts from rocks and the ground and whatnot.

I have seen and heard absolutely zero signs of them starting to die on me. I don’t remember how long the warranty was, but I suspect something ridiculous such as 2-3 years or something. I cannot imagine buying a hard disk which dies after 3 years. I frankly feel as if these are going to last for hundreds of years at this pace, but who knows? Maybe all of them die on me now, and there goes all my data… A frightening thought in many ways, given my empty existence.

On the other hand, if this were the year 2000 and I had a HDD from 1991 (-9 years), I would’ve seen that as ancient back then…

Is there a non-hard disk company-sponsored report or general advice for how long these things can be expected to last in reality?

There’s also the problem of barely any physical space left inside the safe to put any further disks, so I’d ideally have one of them die on me, then replace that, then another dies, and I replace that, etc. But what if they all go at once? Planned obsolescence?

Everything always comes down to money. I just cannot afford some kind of “tape system” for long-term proper archiving.

image stabilization – How much benefit can one expect from a monopod?

I was long a user of monopods out in the field. With the advent of image stabilization lenses, I find I almost never haul it out any more. About the only use case I have for it now is when I’m using my 300/1.4x combo with waterbirds or shorebirds, and even then, I’m most likely to either carry the tripod or go handheld.

I see the use case for monopods in two broad areas: the situation above where you want the ability to reposition quickly but want the added stability, or a similar setup where you’re shooting sports (baseball or football), especially extended sessions where handholding might cause arm fatigue. The third case (locations like museum where a monopod might be allowed and tripod not…) might make sense in certain special cases.

But in general, improvements in lens speed/quality and IS, and carbon fiber tripods reducing weight, have made monopods a niche tool. lighter tripods means I’m not as likely to choose the monopod as a compromise for weight, and remember you can always just put down one leg of a tripod and use it as a funny looking monopod, but you can’t extend the other two legs of a monopod for stability…

In some cases the “string monopod” might be a useful alternative, too. use a bolt in the tripod connector (it’s a 1/4 20, I believe) and attach a string to it that reachers the ground. then stand on the string and pull up to create tension — and it’ll stabilize the camera. I need to experiment more with this, but unless you are using the monopod to avoid arm fatigue, it seems to give you all the benefits of the monopod for stability, at almost no weight and similar stability improvements.

So for me, it’s using IS lenses where possible, and either carrying a tripod or going handheld. monopods just aren’t that useful with modern technology.

firewall – How much DDOS mitigation one should expect from VPS provider?

We had a stateful WebRTC application which received some DDOS attacks. The server had 2gbits port, so any attack over 2gbits was able to make it unavailable. Afterwards we refactored the application to be stateless and now we can deploy it to any number of servers. Currently we are considering to have around 20 VPS with 1gbits ports to handle ~20gbits DDOS. But we also would like to have some protection from the VPS provider and increase our protection. What kind of/How much protection should we look for?

There are providers with auto-mitigation options but we would like to have a configurable firewall and only allow to whitelisted IPs to access our services, if possible. But we couldn’t find any suitable VPS hosting for that matter. Is it because this is the wrong way of thinking when looking for VPS? (gce has that, but networking costs a lot)

dnd 5e – In term of game balance, what repercussions should players expect if DM wouldn’t count Grapple and Shove as “an attack”?

This is how Player’s Handbook (p. 194) describes what counts as an attack:

If there’s ever any question whether something you’re doing counts as an attack, the rule is simple: if you’re making an attack roll, you’re making an attack

There are ambiguous exceptions from this rule though — so-called “special attacks”. There are only two of them — Grapple and Shove from the PHB.

As a DM, for the sake of clarity and consistency I want to call Grapple just “an action” or “a contest”, not “special melee attack”. So instead of

you can use the Attack action to make a special melee attack, a grapple

the text of the house rule (or the errata proposal, if you wish) will be

you can use the Attack action to make an action in combat, a grapple

So does for Shove. This is also consistent with the PHB “Contests in Combat” (emphasis mine):

Battle often involves pitting your prowess against that of your foe. Such a challenge is represented by a contest. This section includes the most common contests that require an action in combat: grappling and shoving a creature. The DM can use these contests as models for improvising others.

So the lowercase “attack” is changed to “action” or “contest”. For instance, the next passage in the Grappling description will be “If you’re able to make multiple attacks with the Attack action, this contest replaces one of them”. The rest of the rules remains unchanged.

I want to figure out what possible impact this will make to the game balance. For instance, will some feats/class features change substantially.

In terms of the game mechanics, what consequences/repercussions this change will have? For sanity’s sake let’s confine ourselves to the the Player’s Handbook.

What can I expect for battery life from my Nikon D5100?

You answered your own question. About 125-140 sounds right. The live view is your biggest drain, so the longer it’s on between shots, the less shots you’ll get.

I don’t use Live View, and have Image Review turned off, and I always carry a spare battery. I shoot all day and often have to change batteries, but never use up the second. Matt is right, if you want more battery life you may want to adjust your technique accordingly. Once you get used to the viewfinder you’ll rarely find a need for Live View.

macbook pro – What to expect at an Authorized Dealer when going for a repair?

I just got my mid-2015 MBP back from Apple. I had a battery problem and assumed it needed to be replaced.

When I arrived they did a quick diagnosis at the genius bar. I was told the battery would be replaced. The genius asked if I did an iCloud backup recently and, if not, I should do one before they took the laptop. I did so it wasn’t an issue.

They explained everything they were going to do and what parts would be replaced. I signed the form and paid for the repair. Throught the repair process I received emails with the status.

In my situation, they completed the repairs and sent me the shipping tracking number for the return. Two days later I had my MBP back. It was a pretty straight-forward, transparent, and quick process.

performance – In what range can you expect a cloud based Sql Server data egress?

Say everything is optimized, queries are simple, indexes are good, etc.

Should a SQL (Azure) database where you spend about 150 to 300 euros per month easily handle data egress with about 250-500 mb per second on a table of ~100 million rows or is that getting close to the limits and should I look at other solutions?

I understand this is a very broad and general question, but I’m looking for something like very rough estimates. The problem is that I have a very complicated legacy project and I am clearly hitting some limits.

I tried (after consulting Azure experts) various other data solutions in the past to only hit other bottlenecks after I migrated the project and had the real production traffic coming along again.

The site has extreme peak traffic in a very short period of time. So it will be on 5% of the database (eDTU) consumption the whole week with about one or two times a day extreme traffic for half an hour (+50.000 very active concurrent users with a lot of dynamic data being requested).

So I’m just looking for a very rough estimated guess so I know if I need to move into a really different direction like i.e. memory-cached microservices.

If 500 mb/second should be no problem then I will try to explore trying to layout my data differently or other SQL based solutions.

plotting – Colorfunction in DensityPlot3D not acting as expect

Im trying to set the color function of a DensityPlot3D output so that it colors the positive values one color and colors the negative values a different color. However, I cant seem to get it to work properly. For example, the relevant code is:

(CapitalOmega) = 
  Parallelepiped({-3, -3, -4}, {{6, 0, 0}, {0, 6, 0}, {0, 0, 8}});

DensityPlot3D(x*y*z,
              {x, y, z} (Element) (CapitalOmega), 
              PerformanceGoal -> "Quality", 
              PlotRange -> All, 
              OpacityFunction -> Function(f, If(Abs(f) > 0.4, Abs@Tanh(f), 0)), 
              PlotLegends -> Automatic, 
              ImageSize -> Medium, 
              AxesLabel -> Automatic, 
              ColorFunction -> Function(f, Which(Sign(f) == 1, Black, Sign(f) == -1, Blue, Sign(f) == 0, Gray))
)

Here, the color function I’m telling it to use is

Function(f, Which(Sign(f) == 1, Black, Sign(f) == -1, Blue, Sign(f) == 0, Gray))

So take the positive values of the product x*y*z and color them Black, take the negative values and color them blue, and take everything else to gray.

This code, when executed by itself, produces

enter image description here enter image description here

which isn’t what I want 🙁 . Am I misunderstanding the arguments of the color function? I read the Doc’s and I think I’m using it correctly, but I guess not. I also tried the function

(Which(Sign(#) == -1, Blue, Sign(#) == 0, Gray, Sign(#) == 1, 
   Black) &)

with the same result.
Im also having an issue with the OpacityFunction, as you may be able to tell in the example image above. The OpacityFunction in the example code should produce an image which is basically transparent in the very center and solid at the faces of the cube (so we should just see a black cube), but the image shows the corners of the cube are being set to 0 opacity. E.g., the point (-2,-2,-2) should have opacity |Tanh(-8)|~1

Im just using an example function above, the real function is way more complicated. I’ll attach the output of actual function I need to color below:

here legend

Im using an opacity function to throw away any values really close to zero, leaving behind the interesting bits.

I appreciate any insight!

equipment recommendation – In general, should I expect better image quality from a 24-70mm f/2.8 lens than from a 24-105mm f/4 lens?

I’m in the market for a full frame EF-mount standard zoom lens, so I’ve been doing a lot of research about different 24‑70mm f/2.8 and 24‑105mm f/4 options. I understand the tradeoffs in terms of focal length ranges and maximum apertures, and I already know that for my purposes, either type of lens would fit my needs pretty well.

What I’m having a hard time figuring out, and what is a high priority for me, is which option would give me the best image quality overall, given the same focal length and aperture. Specifically, the aspects of image quality that aren’t as easy to address in post-processing. So sharpness, contrast, and color rendering straight from the lens are important. Things like peripheral shading and barrel/pincushion distortion can be fixed in post.

I’ve done a lot of searching to try to figure this out, but pretty much everything I’ve come across talks about one of two things:

  1. The focal length range and maximum aperture tradeoffs between a 24‑70mm f/2.8 lens and a 24‑105mm f/4 lens. I’ve already answered that for myself.
  2. Comparisons between different brands of lenses within the same class. These have helped, but haven’t completely answered my question.

From everything I’ve learned, it seems that the Sigma 24‑70mm f/2.8 DG OS HSM Art and the Tamron 24‑70mm f/2.8 Di VC USD G2 are pretty much on par with each other, but the Canon EF 24‑70mm f/2.8L II USM is one of the best zoom lenses in the world, and is superior to both of the others. Unfortunately, the Canon is outside my budget, so it comes down to one of the third-party lenses if I go with a 24‑70.¹

And it seems that the Sigma 24‑105mm f/4 DG OS HSM Art is a fantastic lens, highly recommended by pretty much everyone and seen as more or less equal to the Canon EF 24‑105mm f/4L IS II USM in every way except for zoom ring placement. The Sigma has the zoom ring out toward the front, which bothers a lot of reviewers. Zoom ring placement isn’t such a big deal for me.

So the Sigma 24‑105 has great reviews, as does the Canon 24‑105, and they’re comparable in price. Plus, the Sigma and Tamron 24‑70 lenses are seen as pretty okay, but not stellar. With all that in mind, it seems like one of the 24‑105 options would be best for me. But when I look at MTF charts and image quality comparisons at the same focal length and aperture, the Sigma 24‑70 seems to outperform either of the 24‑105s. That’s got me a little confused.

Is this because people who’ve reviewed these lenses have higher expectations for a 24‑70mm f/2.8 lens than they do for a 24‑105mm f/4? Bottom line, I want to find the lens that, within my budget, will give me the best results overall, not just the best results for a pathetic loser 24‑105 f/4 kit lens or whatever.


¹Tokina also makes a 24‑70mm f/2.8, but I really don’t like the Tokina focus clutch contraption.