Monday, 28 December 2015

Using remote flash in live view while controlled by EOS Utility.

This is just a quick technical tip page that some friends asked me to write up online so they can link to it.

I have been trying to set up my camera to be controlled over USB wire from my laptop, with the shutter being fired under the control of the EOS Utility software in live view mode.

This part is simple but the hard part was that I also wanted to have a remote flash fire when the camera shutter was triggered. The flash setup was a YONGNUO 2pcs YN-560 IV Flash Speedlite with 560TX-C Transmitter.

It turns out that trick is that the silent shutter option on the camera body has to be disabled from within the camera menu. The camera also has to be in Tv, Av or M mode, and not auto or creative auto. In auto or creative auto, the option to disable the silent shutter disappears and the flash no longer fires.



I learned this fantastic tip from Charles Krebs on the http://www.photomacrography.net/ website. Big thanks to Charles. :-)

Sunday, 11 October 2015

Rose leaf


I had a small success with photography today. This is a rose leaf in the garden, photographed in natural light with a Canon 5d Mkii and an MP-E 5x Canon macro lens. I took three shots and photostacked them with Helicon Focus. The shadow and highlights were adjusted, and then the brightness and contrast, and the background was then photoshopped to black using the magic wand tool. I'm quite pleased with the outcome. :-)

Here are a couple of close-ups. 












Tuesday, 15 September 2015

Autumn arrives.


Just a short one today, but did you ever see more promising weather? Fantastic!



Saturday, 29 August 2015

Building an LED-free tv setup.

Our CRT tv gave up recently and we've been working out how to set up a new tv system without having to buy an LED backlit tv. We're doing this because I don't get on with LED screens (described in a previous post).

We have managed to do it and now have a pretty exciting new setup, which we are enjoying very much, and which also saved us a bunch of money. Here's what we did:

Previously we had a Humax box (which records and replays tv), a video player, a DVD player, and a big CRT tv like this:


We also had a 23" CCFL backlit Apple cinema screen, and a tower PC that my son uses for playing computer games and watching YouTube. We decided to try using that as a tv. 

(In case anybody else wants to do this - you need to find a CCFL backlit screen which can be bought secondhand off ebay.) These cannot be connected directly to the Humax box because they don't support the right resolution.

It took a bit of fiddling to organise our new setup, but here's what we have now:

1) Humax box with updated firmware, which is now connected to our house's internal internet. This means that we can programme the Humax to record tv from the browser window of any PC in the house:


The Humax box has a Samba server inside and so it shows up in the file explorer window of the PCs in the house. This means we can drag programme files from the Humax box to any PC in the house to watch them on that other PC.


2) We have the tower PC set up next to the Apple CCFL tv. In practice we drag all the new recorded tv programmes across the internet connection on to the tower PC so that we can watch them easily on the big Apple screen. We then delete them from the Humax box by controlling the box from the PC brower window. This setup is handy as my son has access to all his favourite CBeebies tv shows using the Win 7 file explorer interface which is much faster then the Humax interface. 

3) The internet connection to the Humax and PC is set up using ethernet over power, which means that the network packages travel through the electric wiring of the house and pop out at the power sockets, where we have plugged in special plugs with ethernet sockets. The PC's ethernet cable then plugs into these special sockets. 

4) We also have a USB video capture device in the PC so that we can use the Apple screen as a tv directly using the Humax remote and without having to interact with the PC at all. The quality of the picture is not great, which is why we have the rest of the workaround. 

5) The PC is still in use as a regular PC, still with the Apple screen. It still has the internet connection for online games, and internet browsing and for watching Youtube. We can also use it for photo editing and all the usual stuff. We have a wireless mouse so we can sit far back from the screen for good ergonomics. An extra perk of this is that our son does all his tv watching and computer stuff in the living room where we can see what he's doing and help out. 

6) When we watch DVDs we put them in the tower PC and it plays them directly onto the screen.

We had a lot of fun setting all this up, and the result suits us down to the ground. It cost a lot less than buying a new tv. :-)

--------------------------------------------------------

Here are a couple of photos of our setup. 

Apple screen on the top, PC on the left and Humax box at the bottom in the centre.


In case you were wondering, "Dogtanian" is still great. :-)





Monday, 10 August 2015

Do you have trouble with LED backlit screens?


I am one of the many people who do not get on with LED backlit screens. LED backlit screens are a relatively new phenomenon, introduced mainly because they consume far less electricity than the older CCFL types and CRT screens. Unfortunately for many people LED screens seem to cause a lot of health problems.

For me, the overly bright light from the screens causes pain inside my eyes and blank spaces in my vision, just as if I had been staring at the sun. After only an hour of LED screen use, this effect takes weeks to go away. This is politely known as "eyestrain". Other people apparently experience insomnia and mood changes.

Even more unfortunately, the industry has switched to making *only* LED backlit screens, long before the technology was ready to be used by everyone. This means that a large group of people are no longer able to buy a screen at all and are relying on old devices, while they wait for the industry to solve the LED screen problem.

I, for example am currently relying on:

                     - 5 year old phone, on its second battery,
                     - a 6 year old laptop (much repaired with parts from ebay),
                     - a secondhand CCFL apple cinema screen from ebay,
                     - I have no television, because I can't find one
                       that works for my eyes at all.

It's no longer possible for me to go to a shop and replace any of these items because only LED backlit products are available and I can't use any of them.

I was thrilled recently to see that someone on ebay is selling brand new CRT tvs again. So sensible!

It would be wonderful if the rest of the industry would step back a bit, and start selling the older CCFL screen technology. Even if they only did this for just for a few more years, while they get LED backlit screens working properly, it would be a real lifesaver for those of us who are currently excluded from the use of screen-based technology.


Screen-makers! We need your help. Please listen up!


------------------------------------------------------------------------------------------------

Here are some tips that I have received:

It seems that Eizo do still make just one model of CCFL backlit monitor, although it's very hard to find that out because the backlight type is not specified on the web advert. The monitor is called DV2324-008. 

It is also possible to watch tv from a Humax box on a CCFL computer screen over a network connection by upgrading the firmware in the Humax box. This installs a samba server on the Humax box and allows it to be controlled remotely from the pc without having a tv set. We have set this up and it works. 

A friend has directed me to this BenQ Flicker-free technology white paper. I've no idea whether it is the flicker or the blue light that is the problem for me. I have done a lot of experiments to try to figure it out, but with no success so far. I suspect that the wavelength is at least part of the problem as I have the same trouble with undimmed blue LED backlit mobile phone keypads. 

For the technology luddites amongst us, John's Phone is a true classic. No LEDs in sight, standby time of three weeks. No text messaging unfortunately, or I'd be buying two right now.

TTFone produces nice, basic mobile phones with old school screens and user interface. The TT800 is the only one with non-LED screen and it instead has something called a Chroma screen, which I am waiting to hear more about. 




Thursday, 16 July 2015

DSLR and compact camera comparison


This is a little test to see how two cameras compare at taking exactly the same photographs. Both are set on fully automatic, point-and-shoot mode. 

One is a full frame Digital SLR - the Canon 5d MkII with a Canon 24-105 mm / F 3,5-5,6 EF IS STM lens. The whole setup weighs 1.4kg.


The other is a Canon Ixus 230 HS compact camera, which weighs 140g.



Here are the test photographs:


In these two below, it is clear that the cameras choose very different depth of field when left to their own devices. For really shallow depth of field, the DSLR is the only choice, but both produce very striking photos. 


Ixus     f/3.2      1/50th    100 ISO
DSLR     f/6.3     1/125th      100 ISO


In the two photos below, the DSLR was again clearly preferable because the autofocus on the Ixus was not able to focus on the macro subject in the centre. I'm not sure this is always the case though. I had a different Ixus camera a few years ago that had fantastic macro autofocus down to 1 cm from the subject. I used it to take the photo of a strawberry flower (third photo below): 



IXUS     f/4.5      1/160th      100 ISO

DSLR    f/7.1     1/125th     100 ISO




In these two photos below I can hardly tell the difference between the two cameras:

Ixus      f/3.5      1/100th     100 ISO


DSLR     f/5    1/60th     100 ISO

Again, in these two photographs of pumpkin plants, there is very little difference in focus, but the Ixus seems to have judged exposure much better as the DSLR photo is over exposed. 


Ixus     f/3.5    1/160    100 ISO

DSLR     f/6.3      1/100th      100 ISO


In this wide angle shot of a garden the Ixus seems to have chosen the better settings as the DSLR photograph is again over-exposed. 


Ixus     f/3     1/500th     100 ISO

DSLR     f/7.1     1/125th     100 ISO


So, in summary, the Ixus seems to do better at judging exposure, and the DSLR does better at close-up, shallow depth of field shots. The latter point is somewhat unexpected, given that the DSLR is using a wide angle zoom lens.

The obvious point to remember though, is that the main advantage of the DSLR is that it has huge numbers of extra controls on it, and can even changes lenses, so that shots can be properly controlled. The great advantage of the Ixus is that it weighs 140g rather than 1400g, which really makes a difference. Nice to know that both do rather well under most circumstances on auto though. :-)

Friday, 12 June 2015

renovating a rose bush

Three years ago this rose bush was just a small green twig among a sea of brambles and grass, and hidden under and overhanging apple tree. 


At that time, the rose bush did not do much at all, and it seemed to be on the way out. At first I considered digging it up and replacing it with a new one. However, the border is very hot and dry, and roses bushes take many years to establish a good root system. It seemed better to have a go at bringing this rose bush back. My hope was that its years of root system development would very rapidly enable it to regenerate a strong top growth, if only it could be given a chance. 

First the apple tree above was cut back, and weed suppressing membrane was put round the rose. The brambles are still in position but are gradually being weakened as I repeatedly cut the top growth off. An initial feed of chicken manure was given in the first year and then weekly feeding with tomorite in the following year. The next year I gave a one-off feed with rose fertilizer. This year I have not started feeding the bush yet, but it seems to be doing fine. 

Here is the rose bush seen from a distance, above a sea of Osteospermum jucundum var. compactum. These plants do extremely well in a dry hot border as they have adventitious roots along the length of every stem, which gives them the very best chance of drawing up enough water to counteract the constant drying of the hot sun.


The rose bush is a real splash of colour now and flowers very freely, with no effort at all from me. I'm glad to have given it the benefit of the doubt. Its many years of establishment in this spot have given it a huge advantage in the hot dry ground and it really shows its mettle now - with a huge display of flowers each summer. If you ever find a similar rose bush that just seems like a twig, then I think it's well worth having a go at pepping it up a bit. 

Tuesday, 28 April 2015

Bud-watch 2015 - part 2

This is a continuation from Bud-watch 2015

The great question on that page, was when the buds would finally open and declare the arrival of spring. The answer this year was just a little bit before the 13th April, when the photos below were taken:


The rhubarb leaves are expanding nicely:



This is one of the first apple buds, photoshopped onto a black background because the greenhouse behind clashed, just toooooo much:


The strawberries are well into their stride.


The apple buds are starting to open. 


The cherry is just beginning to open its buds.



...and the wildlife is on the march too. :-)




There is now a bit of a question about whether a frost will come and knock off all the flower buds, but hopefully now we are just heading right into summer. If there is no frost, it's good for us. If there is a hard frost then it's good for the garden centres, who will be selling oodles of replacement vegetable plants to keen gardeners. One way or another, it's all good. Happy spring to you!



Sunday, 26 April 2015

Raspberry pi temperature sensor

Today we've been having a go at another Raspberry pi project. This one is an O'Reilly "Raspberry Pi Cookbook" recipe.

Just like last time, the process went quite well, but getting the right colours of wires connected to the right terminals was really quite hard. I'm noting it here to help others who may be attempting the same project.

I used this temperature sensor from ebay, with the part number (DS18B20) as listed in the book. The three wires were coloured yellow, red and black, even though the documentation stated that they should be output lead: red (VCC), green (DATA) , yellow (GND).

The wires have to be connected from the pi, to the breadboard, to the temperature sensor as in the diagram in Figure 12-16 in the book.



Below is the bird's eye view of the breadboard. The temperature sensor colours go red, yellow, black from top to bottom. That was the hard part, and once we got it right, we were pretty much there. The pi wires are red at top left, white at bottom left, and black in the middle on the right. The resistor was only 1kΩ, as that was what we had handy and it didn't seem to matter which way it faced.




Below are a few more angles to show the detail:


This photo below also shows the jumpers attached to the raspberry pi, as in the Raspberry Pi Cookbook diagram. The positions are made clear in the book. 



We took the python programme from the website that comes with the book at raspberrypicookbook.com and saved it on the pi as temperature.py.

We controlled from a laptop connected to the pi via putty over the wireless internet. 

It worked just fine except that the very top line of the programme was missing so that it was not automatically run as a python script. We added "#!/usr/bin/env python" to solve this problem. 

We typed "chmod +x temperature.py" just the first time to change the permissions. 

We then used "sudo ./temperature.py" to run the programme each time. This is what the output looked like.





Success! Thank you to Simon Monk, the author. That was fun. 






Friday, 10 April 2015

Good wildlife today


The butterflies are in fantastic form in our garden this week. I have no idea what this one is but it likes our plum tree. We've also had two greenfinches stripping the petals off the tree and flying off with bundles of them poking out from the sides of their beaks. It must be the busy season!

Thursday, 9 April 2015

A new kind of alpine garden


I have been setting up a curve of block paving in the garden with the plan of taking out a few bricks further down the line to plant alpines.

This is a very similar to the planting scheme that Geoff Hamilton used to use in Gardeners' World many years ago when he planted alpines in the gaps between paving slabs in a patio. I'm using block paving because it is cheaper and also easier to make into curves.

I have one plant in a gap so far, and I'm growing a whole lot of mixed alpines from a seed packet from Chiltern Seeds. I'm hoping to fill in lots and lots of little holes with these mixed alpines, so that in the end the bricks are almost entirely obscured.  This is an exercise in cheap-skate, low maintenance gardening!



Thursday, 26 March 2015

depth of field of macro lenses.

This is a comparison of the depth of field of macro lenses. I am doing this so I can choose the most appropriate lens for focus stacking or macro photography.

Canon 1-5x MP-E 65mm f/2.8


Magnification       Depth of field

x1                                0.8mm
x2                                0.3mm
x3.5                             0.1mm
x5                                0.07mm

Data from http://pikespeakphoto.com/tests/canonlens_mp-e.html.


Olympus Zuiko x0.5 50mm f3.5 with 12mm extension tube


Aperture                    Depth of field       
                                (Meaured roughly,
                              by photographing a ruler)

f3.5                                   about 5mm
f5.6                                   about 10mm
f8                                      about 20mm
f11                                    about 25mm
f16                                    about 35mm
f22                                    about 70mm





Wednesday, 25 March 2015

Focus stacked rose bud

Today I have been trying again with my focus stacking system. This time experimenting with a larger subject, and a black background.

The focus stacked image below is a small rose bud that is in the process of opening. It was taken at x1 magnification. It's come out quite well.


Below is one of the slices from which the image was compiled. 



This is a close up of the image. I like the detail on the leaves very much. I think that keeping the subject completely still is going to be a challenge, with soft material like this. 



One of the challenges as keeping the light levels stable as my subjects are lit with natural light through a window. Helicon focus reports on the fluctuations of light levels, and for the coin that I used for scale today the light levels fluctuated by 22%. No fluctuating light level was reported for the rosebud image above. It's clear from the image below that movement has been a problem with the rosebud. No similar problems are seen with this more easily anchored subject. 



Next plans:

I think the next thing will be to work out the exact depth of field of my macro lenses and figure out the minimum number of slices needed to cover a given specimen. Perhaps if I can get the minimum number of really good slices then I can eliminate the ghosting. 

Out of interest, here is the rosebud image with the black background turned completely black in photoshop. I suppose that could be good or bad depending on the application of the image. 






Tuesday, 24 March 2015

A Fern Crozier of Extreme Smallness

This page follows on from Focus Stacking Coins of the Realm.

The aim of my focus stacking project is to take photos of tiny, tiny ferns, and today I am making my first attempt. So here it is, a fern crozier of extreme smallness.

This focus stacked photo was taken using the smooth.py script described on my previous blog page.

The crozier is the new unfolding leaf of a sporophyte fern plant. This leaf shown below is only the third leaf ever to be produced by this plant. I think it's turned out pretty well. The next thing will be to get the background and lighting right so that the detail is more clearly visible.

The big green splodgy thing on the bottom left of the photo is the gametophyte fern.



Below are a couple of the individual photos from which the focus stacked image above was compiled (using Helicon Focus). As you can see, depth of field is a bit of an issue at this level of magnification (5x). The image was taking with a Canon 5d MkII and a Canon M-EP 5x macro lens.



Here are some photos of the setup that I used to take the photos:

















This is a photo of the plant, back in it's pot, looking very small indeed.