Sunday, 8 December 2013

raspberry pi as a backup machine

Various things recently (not least cryptolocker and a *much* faster internet connection with an upgrade to ftc) made me start thinking about getting better organised at backups. I currently have around 2Tb of photos (on windows), lots of music (mostly recoverable from CDs) on linux and random other stuff.

With Raspberry pi idling at around 2 watts, using a huge disc on a headless pi as a backup point for the whole house seems an attractive option, and could act as a staging point for offsite backup as well (I've now got >10Mb upload speed, so trickling up at say 5Mb would get through a lot of data in a day).

After a bit of digging around, CrashPlan looks like the best option, so below are notes on first steps to getting CrashPlan going.

(note I am continuing to use CrashPlan, but running on an x86 box, rather than pi - see this post for explanation)

Tuesday, 19 November 2013

Razberry: config cleanup and add temperature sensor

The very simple config last time had silly icons and didn't really do the right things, so the first thing is to clean up the config a bit. After that I'm aiming to get a temperature sensor on a fibaro universal sensor working

Saturday, 21 September 2013

Light box - major construction complete

The new lightbox now has all major parts in place, there is just some finishing work to do - painting the outside and a couple of bits of frame, and fitting handles, catches and cable clips.

Here it is packed up, its 180cm X 56cm X 20cm. There's a 1m ruls sitting on top of it

Wednesday, 18 September 2013

RaZberry: running as a service

Running as a service means openhab will automatically start when rpi starts up and will shut down when rpi shuts down, it can also be shutdown at any time from the console (for example, to run z-way to pick up new or changed device configurations).

This script is based on the one Victor Belov posted here changed thus:
  1. directory and user names changed (ECLIPSEHOME, RUN_AS)
  2. added to DAEMON_ARGS
  3. simple 3 generation log recycler

RaZberry: Stripping down the configuration

The demo config is good as a demo and as a simple howto, but I'd rather keep the config simple and add things into it as needed. This keeps logs and the UI simple.

Tuesday, 17 September 2013

Saturday, 17 August 2013

new print lightbox - construction starts

Initial thoughts were to construct primarily of 6 mm marine ply, as this would save considerable weight compared to a chipboard style of construction (which our previous lightbox used), this would be offset by the larger size of course, however after discussing a number of approaches, we decided that a space frame type construction, skinned with ply, would be a better option.

There are these nice parts in the USA, but trying to match inches with SWG wall thickness to metric threatened my sanity, apart from lead times and import problems, so I went with Easyfix from here

Here is the base unit built from 25 mm square tube using standard corner pieces. This weighs 3.8 kilos.

The top will be slightly lighter as it is not as deep. The light fittings are 0.7 kilos each.

I'm still waiting for more parts to arrive, but I have further refined the sketchup design and produced this animated video showing how the main parts pack away.

Friday, 16 August 2013

new print lightbox - proof of concept

Well that's just fancy words for a quick lash up...

I found that B & Q do a nice range of fluorescent fittings with electronic ballast that are also very compact. They also conveniently trap all the light coming out of the 'back'. I aim to make sure that only the light that is necessary shows, all the other light is, as far as possible, stopped. These fittings will take the tubes that we really want to use.
Using some big pieces of cardboard and handy black paint.....
I decided not to paint the background as it would probably have gone wrinkly which would have made the illumination measurements more difficult.

new print lightbox - getting started and theory

My local photography club decided the time had come for a new lightbox for viewing prints (both general viewing and for competitions).

The old lightbox used low voltage quartz halogen bulbs above and below and worked fairly well, but it was difficult to view more than 1 print at a time and it has a black background, which is no longer à la mode.

Could we invent a better mousetrap?

Tuesday, 12 March 2013

time for version control - setup subclipse

Notes on setting up subclipse for my ickle projects

Here's a useful thing on subclipse on 12.04

  1. updated eclipse to latest everythings, now on 3.7.2
  2. sudo apt-get install libsvn-java
  3. check subclipse not installed already - OK
  4. Used info at link above to install subclipse 3.6
  5.  restart eclipse and add required project to the repository (svn+ssh://servername......)

Now for the server

  1. sudo apt-get install subversion
  2. create a new repository with
    svnadmin create ~/pootlesrepo
  3. setup basic security: - add this to ~/pootlesrepo/conf/svnserve.conf
    anon-access = none
    auth-access = write
    password-db = passwd 
  4. setup a user in ~/pootlesrepo/
 That's it ready to go

Friday, 8 February 2013

lightbox mods - illumination

Here's some shots of the illumination from the original and modded Lastolite hotrod.

Placed on the floor angled up at approx 45 degrees with the nearest part of the box 12" from the surface.

flat black background curtains
The modded version gives a better spread along the length and also gives a more wrap-around light, particularly near the center (which is what you would expect)

Monday, 28 January 2013

more details on Lastolite hotrod strip mods

Pretty basic really, here's a couple of photos of what I've done inside: (Colour balance is weird as under led lamps and not adjusted). Also I've set the box horizontal 'cos it is easier to work with and photo while messing about.

This first shot shows the original internal baffle, which I have folded in the middle to shorten it, temporarily attached with peelable tape.  I folded the middle section (which is double thickness into 3.  This allows some light from the flash & reflector to leak directly to the ends of the front diffuser.

Removing the inner diffuser (now lying on the bottom) shows the prism reflector in place.

and here is a shot with the prism reflector also removed.  The flash is a Canon 270Ex II sitting on top of a pixel king, and set to tele mode (front element pulled forward).  I'll give it a go with some other flashes ion a day or 2 to see how it behaves.

The prism is 2 pieces of card 10cm wide the joined edges are 15.5cm long (which allows it to fit snuggly up against the hot shoe mount ring) and the edges nearest the front of the box are 17cm. They are at an angle of 85 degrees.

It's held in place for now with a couple of small strips of blu-tack to the top and bottom faces.

I made the prism with card covered in aluminium foil - probably easier to use silver mirror card if you have it to hand _ did think it might be necessary to crumple the foil slightly, but this doesn't seem to be needed.

Saturday, 26 January 2013

Lastolite hot-rod strip review and mod

Finally decided on a hot-rod strip as the long softbox to get - there are a few positive reviews out there like this and this (which is really a video review), and no negative ones I found.
As regards general use and assembly these reviews are good, but I soon noticed that if the box is close to the subject it has a tendency to give a 'hot middle'.  You can also see this in the photo's of Sarah in the first review.  Indeed the reviewer says "At close range the illumination starts to fall off in a full length shot. So here the the feet are underexposed." In fact imho the central part is tending to overexposed - in both the full length and the 3/4 shot. A quick photo of the box itself shows why this isn't really surprising.Photo of the strip box showing eveness of illuminationThere is a big fall off from the centre to the ends of the box. In fact looking at the histogram shows there is just over 2 stops drop off from the centre to the ends.

This may not be a problem, depending on how you will be using the box, but it does constrain how close you can place the box the the subject - and normally you want to get the box as close as practical both to increase the effectiveness of the box, and to reduce the power needed (we are talking battery flashes here after all).

So I wondered if it would be practical to improve this situation. Here is the result of an afternoons messing about with silver foil and fabric stiffener.

A big improvement, confirmed by the histogram below.  Now we have about 0.8 stop variation in output along the length of the box.  And yes - this does make for more even lighting when the flash is close to the subject.

I'll publish info on how to do this tomorrow.

I've also added some piccies of the illumination from the original and modded versions here

Sunday, 13 January 2013

2nd Curtain flash with Canon 7d and *various* kit

I got quite interested in using 2nd curtain flash recently, and have struggled to find out what is and isn't possible. Fortunately more is possible than I initially thought so here's what I have found.

Rule 1

You can only use 2nd curtain flash in 'local' mode - i.e. with Wireless func. disabled. This limits various things, like camera control of flash power by groups, but is by no means a show stopper, and certainly doesn't stop the use of off camera flash, or multiple flashes.

I'm only interested in manual use of flash.

So I haven't tried out anything related to auto flash things.


Things that work:

simplest use: built in flash plus extras

Using any flash fitted with an optical slave trigger, on camera flash can be turned down quite a bit (32nd works where other flashes to be triggered are within a few feet annd not too far off axis). Suck it and see.

I've done this with some studio flashes and using an old Soligor flash synchro unit which triggered an old Sunpack flash. (Can't even find an internet ref to the slave device, but it works well)

If the on camera flash is a problem, I switch to using Pixel Kings to do the first triggering.


MORE POWER: Canon flash in hotshoe

I can plug a speedlite into the camera hotshoe to get a bit more power or point the flash up for some bounce, and trigger further flashes optically as with the built-in flash.


Using a ttl flash extender cable

I've not done this myself, but this would be the logical next step if the length limitations aren't an issue (and a lot cheaper than wireless remotess..)


Using wireless (radio) remote triggers - Pixel Kings

 This gives slightly more control over at least a couple of flash units.

I have 2 Pixel King receivers working with 2 Canon 270EX IIs. The flash power of both can be set through the in-camera menu, but of course this sets both to the same power (but is still a lot better than nowt). Further flashes can of course be triggered from these if they use / are fitted with optical slaves.