Mirrorless cameras and Night photography

I am planning to buy Sony A7 mirrorless camera but there are 2 points where I need more clarity:

  • Are Mirrorless cameras less efficient in low light specially Sony mirrorless cameras. I read somewhere that for Night Photos actual view from Viewfinder/LCd screen will be very different from actual photos
  • Are lenses going to be more expensive for Mirrorless cameras as compared to DSLR.

It will be helpful if someone can clarify on above points.

dnd 5e – A PC in Curse of Strahd is cursed by Mother Night and eats a dream pastry. What happens?

A PC in Curse of Strahd has the opportunity to be cursed by Mother Night, at which point they are

haunted by horrible dreams every night lasting from dusk until dawn…A creature cursed in this way gains no benefit from finishing a short or long rest at night (resting during the day works normally, since the curse is dormant from dawn to dusk).

On the other hand, a PC who eats a dream pastry

must succeed on a DC 16 Constitution saving throw or fall into a trance that lasts for 1d4 + 4 hours, during which time the creature is incapacitated and has a speed of 0 feet. The trance ends if the affected creature takes any damage or if someone else uses an action to shake the creature out of its stupor.
While in the trance, the creature dreams of being in some joyous place, far removed from the evils of the world.

As luck would have it, one of the PCs in my current CoS campaign has been cursed, although he has not yet slept. He is also the only PC to have previously eaten a dream pastry. If he realizes the effects of the curse and decides to counteract it with a dream pastry, what would happen?

RAW are ideal, perhaps drawing on precedent for the power of curses vs. magic items, or divine magic vs. fiends. If no RAW answer is forthcoming, an answer can separate itself from mere opinion by relating experience (what happened in your campaign and how it was received), lore relationship between hags and Mother Night, or lore from the Ravenloft setting in any edition.

uk – Is a 13-hour layover in the middle of the night enough time to go see Buckingham Palace?

As you’ve got to make the journey between airports anyway, I say make the most of it. Sleep on the plane if you can and see the city at night. I’d pack in one backpack (hand luggage strapped on top) and do it on foot, but taxi/bus/night tube (Friday and Saturday) are other options.

The last tube train from Heathrow is at 23:35 (T4) or 23:42 (T5), a few minutes later for T123. So you should have plenty of time to clear immigration, retrieve your luggage and get the tube. There’s also the TFL line train but that goes to Paddington station which is 3 km from Buckingham Palace). You can check for planned/emergency issues online at Transport for London’s website.

If you get the tube, you can go to Hyde Park Corner, less than 1 km away from the Palace.

In the morning I used to quite often get an early train out of London Bridge to Gatwick. Currently that looks to be 05:35, getting in at 06:04. That should be plenty early enough for most flights but you’d need to check.

Assuming you’re happy to walk through the night you can see a lot of London. Here’s a quick 10 km route suggestion I threw together. It takes in Buckingham Palace, Parliament Square (but not Big Ben/Elizabeth Tower which is being repaired), the Embankment, Trafalgar Square, Covent Garden, the Strand (you could night-bus this bit), St Paul’s Cathedral, the Tower of London and Tower Bridge.

Here’s a picture in case I carelessly delete the route
Picture of route on Strava

Night buses from Trafalgar square will get you to many places but they’re not very frequent. I’ve deliberately omitted airport buses in the interest of maximising your time in London. The tube and regional trains aren’t all that expensive, and are much quicker; they’re also less much affected by traffic, though there are rare delays in the middle of the night.

An alternative is to cycle all or part of the route – at least if you have a fairly small backpack. There are several bike hire schemes in London. The official (Santander-sponsored) scheme is well regarded. It has its own sightseeing loop suggestions. I rode a route similar to the walking route I suggest above yesterday (as part of a much longer ride). The most significant difference was probably to make good use of the Embankment cycle path. Cycling in London, at least in my limited weekend experience, compares favourably to many UK cities.

system settings – Night Light not working in Ubuntu 20.04

Today I realized that Night Light stopped working in my machine. When I try to set it up, nothing happens. See attached gif:

trying to enable night light

I am not sure what’s causing it to fail. I don’t know if there are any logs generated by this tool, or if there’s another way to enable Night Light.

Any idea what to try? This was working a few months ago.

When I check /var/log/syslog, there are some messages related to night light when I use the «Sunset to Sunrise» schedule, but nothing indicates that it failed:

Sep 19 22:46:37 sambayon gnome-control-c[22940]: no sunset data, using 16.00
Sep 19 22:46:37 sambayon gnome-control-c[22940]: no sunrise data, using 8.00

raw – Circular Pattern in Night Sky Image

I do not think this artifact is caused by reflections in the optical path. I think this is due to software correction of light falloff as a function of distance from image center (i.e., vignetting compensation). Normally such correction is not very noticeable because the signal-to-noise ratio (SNR) is high enough. But in this case, the image is so dark, that lifting the the image by a couple stops towards the corners greatly magnifies the noise in those regions as well.

Notice that the noise at the top, above the outer ring, and in the bottom center and lower right, is substantially more pronounced (“grainier”) than in the center. There is nothing optically that would cause radially-biased digital noise. That has to be a result of software increasing the signal level (i.e., digital multiplication). The upper-right and upper-left corners outside of the ring especially show a lot more noise. Optically, these regions should be darkest due to vignetting, so their SNR is lowest. After digitally boosting the corners for light falloff, the only signal there is just boosted noise.

jpeg – Why is the night sky photo showing uneven color and strange pattern in background?

Colors of the stars

Very small light sources are a problem with the rendering of color from the sensor. Basically the star itself is not much bigger than one pixel, but you will light to some red, green and blue pixels. This can lead to the color of the stars going off, depending how many of the rgb pixels of the sensor get some light from it.

On larger light sources, the color would even out, but here a shift can occur.

Then, with small light sources, chromatic aberations might become more distinct around the lights, affecting the color as well.

A last effect is high iso noise, why can also contribute.

Color Patch

This sees to be light pollution from dust in the atmosphere which lights up with the lights of cities nearby.

uk – If I land in London the night of September 9th, will I be required to self isolate until September 22nd or September 23rd?

A strict reading of the rules simply says 14 days, and as such the sensible thing to do would be to consider that 14 full 24 hour periods, so if you entered the country at 8pm (for example) on the 9th of September, then your isolation period would end at 8pm on the 23rd.

This isn’t the sort if thing to skimp on, keep yourself and others safe.