## Lens – Do mounting adapters change apparent focal lengths of lenses?

I have a Sony A6500 APS-C camera using a Sony 55-210mm lens.

I wanted more scope and so I rented a Sigma 18-300mm lens to use with a Sigma MC11 adapter.

By testing this configuration, I get an identical picture with the Sony lens at 200mm and the Sigma at 300mm.

The Sigma lens setting on 200mm gives a wider-angle picture compared to the Sony 200mm lens. It seems that the cropping factor of 1.5 is revised when using an adapter.

Why does the Sigma lens seem to have different focal lengths for the Sony lens? Is this caused by the adapter?

## digital integration – How to integrate this oscillatory function with apparent singularities

I want to integrate the following function with respect to x, between 0 and + Infinity:

``````-1/Pi Exp(-2 Pi x) Abs(w^3) (Abs(w))^(-x) Gamma(1 - x) Gamma(x - 3) (Sin(Pi x/2))^2 Cos(Pi x/2)
``````

w is a parameter that ranges from – Infinity to Infinity, but you can set it to 2 if you wish. As you can see, it has oscillatory factors and apparent singularities (since the Gamma function diverges but Sin is equal to zero and the overall result is finite) to positive integers.

By trying to integrate, I get the error

NIntegrate :: ncvb: NIntegrate failed to converge to the prescribed accuracy after 9 recursive bends in x near {x} = {0.996132}. NIntegrate obtained 0.008228086311816908`and 7.945116181892624`* ^ – 6 for the integral and error estimates.

I've tried to define Method -> "LevinRule", to define a higher working precision, but nothing has worked …. any ideas?

## Why does an increase in Y-chain contrast cause apparent desaturation?

And is this the same phenomenon we see when colors appear less saturated in the middle of the day compared to dawn and dusk (when the contrast of brightness is reduced)?

## linux – virt-install crashes, no apparent error in the logs, and the virsh list shows its execution after the ctrl c output, no domifaddr if

I was thrown into a management box that virtually the person before me was using virtually, so trying to upgrade. As a test, make a virtual installation of this:

``````virt-install --virt-type = kvm --name kosmos-icc --ram 1000 --os-variant = centos7.0 --cdrom = / var / lib / libvirt / boot / CentOS-7-x86_64-Minimal- 1810.iso --network = bridge = virbr0, model = virtio --graphics vnc - disk path = / var / lib / libvirt / images / centos7.qcow2, size = 8, bus = virtio, format = qcow2 --boot userserial = on
``````

It works with this:

``````WARNING Charts requested but DISPLAY is not set. Do not run virt-viewer.
WARNING No console to launch for the guest, default --wait -1

Start the installation ...
Allocation of & centos7.qcow2 & # 39; | 8.0 GB 00:00:00
The installation of the domain is still in progress. Waiting for the end of the installation.
``````

Then I block, I can press ctrl-c and get my prompt, make a list virsh shows that it is running, but do a virsh domifaddr kosmos-icc shows nothing (the other that is generic and which was installed with the mistletoe) shows the IP address (which I can ssh in) of the machine.

So, I do not know why it does not finish or if it is silent and if I miss a switch. I assumed virbr0 was the way to go with the network. So we must continue to learn virsh / virt and see if I can via a command line install a virtual machine and then replicate the process on an untested machine.

The installation logs in /root/.cache/virt-manager do not show any real errors … in fact, they indicate:

``````[Wed, 19 Jun 2019 11:28:38 virt-install 351]    DEBUG (guest: 441) XML retrieved from the libvirt object:

... the xml ...

[Wed, 19 Jun 2019 11:28:38 virt-install 351] DEBUG (virt-install: 744) State of the domain after installation: 1
``````

This state after installation is the last line before the log shows the interruption of my ctrl-c keyboard.

## E-commerce makes apparent use of one-page application infrastructures as multi-page applications

When I see e-commerce in my country, I see refills of pages that lead me to think that they use MPAs and not front frames. I talked to colleagues and they said that they were actually using SPA frameworks, but that they were using some techniques whereby SPA websites behaved like VMCs traditional. They can thus benefit from the modularity of the front-end frameworks and not lose their SEO. If so, what technologies could be used with Angular to address the behavior of MPAs.

## drivers – An apparent random pattern of PKCS # 7 errors in dmesg

The error appears explicitly when launching the nvidia card with the help of bumblebee and when launching the realtek driver. And I remember well, also with the wifi driver. I have no strange behavior with the machine, it seems to work well. I have degraded the driver and kernel multiple times and the error persists. Currently, I have the latest and APT is up to date:

``````                                                                                                        ./+o+- david @ turing
yyyyy- -yyyyyy + OS: Ubuntu 16.04 xenial
: // + ////// - yyyyyyo Core: x86_64 Linux 4.15.0-46-generic
. ++ .: /++++++--.+ sss / `Availability: 16m
.: ++ o: / ++++++++ /: -: / - Packages: 3466
o: + o +: ++. `..``` .- / oo +++++ / Shell: optirun screenfetch
.: + o: + o /. `+ sssoo + / Resolution: 1920x1080
. ++ / +: + oo + o: `/ sssooo. FROM: XFCE
/ +++ // +: `oo + o / :: -:. WM: Compiz
+ / + o +++ `o ++ o ++ ////. WM Theme: Ambient-MATE
. ++. o +++ oo +: `/ dddhhh. GTK Theme: BlackMATE [GTK2]
. +. o + oo:. `oddhhhh + Icon Theme: elementary-xfce-dark
+. ++ o + o`` -````` .: ohdhhhhh + Font: Without 10
`: o +++` ohhhhhhhhyo ++ OS: CPU: Intel Core i7-7700HQ CPU @ 3.8 GHz
.o: `.syhhhhhhh / .oo ++ o` GPU: GeForce GTX 1050 Ti
/ osyyyyyyo ++ ooo +++ / RAM: 3103MiB / 15906MiB
`` `` `+ oo +++ o :
`oo ++.

With nvidia-415
``````

I leave here a big part of the output of dmesg:

``````[   11.320704]    snd_hda_codec_realtek hdaudioC0D0: mono: mono_out = 0x0
[   11.320705] snd_hda_codec_realtek hdaudioC0D0: entries:
[   11.320706] snd_hda_codec_realtek hdaudioC0D0: Headset = 0x19
[   11.320707] snd_hda_codec_realtek hdaudioC0D0: Mic for headphones = 0x1a
[   11.320708] snd_hda_codec_realtek hdaudioC0D0: Internal Micro = 0x12
[   11.348139] Unsigned PKCS # 7 signature with trust key
[   11.358876] Unsigned PKCS # 7 signature with trust key
[   11.359416] Unsigned PKCS # 7 signature with trust key
[   11.399690] Bluetooth: hci0: Intel firmware fix completed and enabled
[   11.439431] Unsigned PKCS # 7 signature with trust key
[   11.447720] Unsigned PKCS # 7 signature with trust key
[   11.450533] nvidia-uvm: Loading the UVM driver in mode 8, major device number 238
[   11.474240] support: Linux support interface: v0.10
[   11.480096] Linux video capture interface: v2.00
[   11.628784] uvcvideo: UVC Camera 1.00 detected - Integrated webcam (0bda: 568a)
[   11.629867] uvcvideo 1-12: 1.0: The type of entity for the entity The extension 4 has not been initialized!
[   11.629886] uvcvideo 1-12: 1.0: The type of entity for the entity The extension 7 has not been initialized!
[   11.629887] uvcvideo 1-12: 1.0: Type of Entity for Entity Processing 2 has not been initialized!
[   11.629888] uvcvideo 1-12: 1.0: The type of entity for the entity Camera 1 has not been initialized!
[   11.629982] input: Integrated webcam: W integrated under /devices/pci0000:00/0000:00:14.0/usb1/1-12/1-12:1.0/input/input19
[   11.630058] usbcore: new interface driver registered uvcvideo
[   11.630058] USB Video Class Driver (1.1.1)
[   11.787465] input: HDA Intel PCH headset microphone under /devices/pci0000:00/0000:00:1f.3/sound/card0/input20
[   11.975100] Added Exchange 8000508K on / dev / sda7. Priority: -2 Extents: 1 out of: 8000508k FS
[   11.997623] EXT4-fs (sda9): mounted file system with ordered data mode. Opts: (null)
[   12.196930] audit: type = 1400 audit (1552787830.489: 2): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / sbin / cups-browseed" pid = 896 comm = "apparmor_parser"
[   12.197360] audit: type = 1400 audit (1552787830.489: 3): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / lib / snapd / snap-confine" pid = 894 comm = "apparmor_parser"
[   12.197362] audit: type = 1400 audit (1552787830.489: 4): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / lib / snapd / snap-confine // mount-name-capture-space- capture "pid = 894 comm =" apparmor_parser "
[   12.197569] audit: type = 1400 audit (1552787830.489: 5): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ snap / core / 5145 / usr / lib / snapd / snap-confine" pid = 888 comm = "apparmor_parser"
[   12.197572] audit: type = 1400 audit (1552787830.489: 6): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ snap / core / 5145 / usr / lib / snapd / snap-confine // mount- namespace-capture-helper "pid = 888 comm =" apparmor_parser "
[   12.197950] audit: type = 1400 audit (1552787830.489: 7): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ sbin / dhclient" pid = 887 comm = "apparmor_parser"
[   12.197952] audit: type = 1400 audit (1552787830.489: 8): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / lib / NetworkManager / nm-dhcp-client.action" pid = 887 comm = "apparmor_parser"
[   12.197954] audit: type = 1400 audit (1552787830.489: 9): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / lib / Network Manager / nm-dhcp-helper" pid = 887 comm = "apparmor_parser "
[   12.197956] audit: type = 1400 audit (1552787830.489: 10): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / lib / connman / script / dhclient-script" pid = 887 comm = "apparmor_parser "
[   12.198833] audit: type = 1400 audit (1552787830.489: 11): apparmor = "STATUS" operation = "profile_load" profile = "unconfined" name = "/ usr / sbin / tcpdump" pid = 921 comm = "apparmor_parser"
[   12.722282] Bluetooth: BNEP (Ethernet emulation) version 1.3
[   12.722283] Bluetooth: BNEP Filters: Multicast Protocol
[   12.722286] Bluetooth: initialized BNEP plug layer
[   12.981785] hdaps: init init of the driver failed (ret = -19)!
[   13.031013] r8169 0000: 02: 00.0 enp2s0: link down
[   13.036682] applesmc: driver init failed (ret = -19)!
[   13.102774] acer_wmi: Acer Laptop ACPI-WMI Extras
[   13.102780] acer_wmi: WMI interface unsupported or unsupported, unsupportable
[   13.597882] nvidia-uvm: Discharge the UVM driver in mode 8
[   13.781284] bbswitch: disable discrete graphics
[   15.694575] Bluetooth: TTY RFCOMM layer initialized
[   15.694579] Bluetooth: initialized RFCOMM socket layer
[   15.694582] Bluetooth: RFCOMM version 1.11
[   18.098078] Non-volatile memory driver v1.3
[   18.934574] wlp3s0: authenticate with f8: 98: b9: 19: b9: 0c
[   18.937159] wlp3s0: send authentication to f8: 98: b9: 19: b9: 0c (try 1/3)
[   18.939361] wlp3s0: authenticated
[   18.940022] wlp3s0: associates with f8: 98: b9: 19: b9: 0c (try 1/3)
[   18.943841] wlp3s0: RX AssocResp of f8: 98: b9: 19: b9: 0c (capab = 0x1411 status = 0 help = 5)
[   18.949994] wlp3s0: associate
[   19.014024] wlp3s0: Limitation of the transmit power to 30 (30 - 0) dBm as announced by f8: 98: b9: 19: b9: 0c
[   98.270124] bbswitch: enable discrete graphics
[   98.568294] Unsigned PKCS # 7 signature with trust key
[   98.580196] nvidia-nvlink: the Nvlink kernel is being booted, major device number 241
[   98.580508] nvidia 0000: 01: 00.0: vgaarb: VGA decoding changed: olddecodes = none, decodes = none: owns = none
[   98.679985] NVRM: loading the NVIDIA UNIX kernel module x86_64 415.27 Thu. 17:25:03 CST 2018 (use of threaded interrupts)
[   98.682947] Unsigned PKCS # 7 signature with trust key
[   98.693213] Unsigned PKCS # 7 signature with trust key
[   98.694008] nvidia-modeset: Loading NVIDIA Driver in Kernel Mode for UNIX Platforms 415.27 Thu 20 Dec. 17:06:08 CST 2018
[   98.784287] Unsigned PKCS # 7 signature with trust key
[   98.793090] Unsigned PKCS # 7 signature with trust key
[   98.793562] Unsigned PKCS # 7 signature with trust key
[   98.795222] [drm]    Nvidia-drm initialized 0.0.0 20160202 for 0000: 01: 00.0 on minor 1
[   98.893338] Unsigned PKCS # 7 signature with trust key
[   98.902801] Unsigned PKCS # 7 signature with trust key
[   98.904910] nvidia-uvm: Loading the UVM driver in mode 8, major device number 238
[  129.503090] nvidia-uvm: Discharge the UVM driver in mode 8
[  129.614159] bbswitch: disable discrete graphics
[  129.633411] pci_raw_set_power_state: 25 reminders deleted
[  129.633414] pci 0000: 01: 00.0: Refused to change the power state, currently in D0 mode
``````

## interaction design – What is the most important coherence or ease of use apparent most important?

Just because both are important. If my client does not want one, I'll give an example:

1) Focus on consistency => Your interface will not attract new people. Ten years ago, it would have been good. But today, in the digital world where everyone can sell something that looks like yours, it is not acceptable to avoid the "ease of use" as a whole. Your product will fail and you will lose tons of money on it.

2) Focus of the simple user interface => Simplicity is closely related to self-consistency. Simple is not "stupid", it is to choose "cleanly" all the things you can do. If your interface is not consistent, being simple will not save it from the users does not understand what is happening on the screen because "Yes, you say Payment and after its withdrawal, is it different? ". But still, being simple at first sight does not mean "no depth". According to some hypotheses, to keep the user engaged in something, he must be given an activity related to his skills (Flow theory, CSÍKSZENTMIHÁLYI).

So, for me, there is no good answer to that. In both cases, it will be a failure. Do both and you may succeed (but at least your UX will be great)

## Wgich is more important self-consistency or apparent ease of use?

What is most important:

1. Personal consistency. In other words, the system works the same way for similar actions.

This allows users to reason about the system.

2. Or simplify each part so that they are individually as simple as possible.

This can paradoxically make the system more complex because it is not consistent.

If you are in a situation where choices make one or the other of these things, which ones do you choose and why? How do you motivate this to your clients, who often do not consider the big picture and see only the immediate apparent effect?

## resolution – The game has been resized incorrectly for no apparent reason (GameMaker)

I've exported the game with the following graphical settings:

OBS – Interpolating colors between pixels would be like antiliasing. I do not think that's the cause of the problem, but I'll test it out and come back with a change if that's the case.

I have tested the game on a PC with the following settings: Intel Core 2 Duo e8200 CPU @ 2.66 GHz, 2.66 GHz / 4 GB RAM / e943Fwsk monitor 18.5 "

When checking the aspect ratio, it should not happen:

We discussed with the owner of the LAN home that this could be due to the fact that the monitor is very large and the fact that the PC does not have a video card and its components do not support the size of the monitor. But he certainly did not give me.

Curiosly (or not), it was the only computer that did not have a version on DirectX. The DirectX was installed with the game by the game's installer itself. If I'm not wrong in version 9, most computers have at least version 11.