PhotosbyKev

A few experiments in Timelapse photography using a motorised programmable pan/tilt head as a mount for a Canon 7D camera.

The first test

1 hour 40 minutes  of shooting compressed to 16 seconds to make a timelapse video of the tide receding from the Cemaes bay harbour.

480 separate images were taken on a Canon 7D, 0.5 second @ f22 iso 100 at 12 second intervals. The camera was mounted on a programmable motorised Merlin pan/tilt head and a Nokia N800 running Papywizard software was used to remotely control the camera and the head using bluetooth.

Using this control method means that the pan/tilt head is paused and stabilised before each image is exposed.

A 3 stop ND filter was used to get the longer shutter speed and a 2 stop graduated ND filter was used to balance the sky and foreground.

Uploaded to youtube as a HD 1080 video

The second test (taken the following day)

In this test the Merlin pan/tilt head was constantly rotating at x8 sideral rate (120 degrees/hour) and the camera was being fired by an intervalometer at 5 second intervals to produce 680 images in approximately one hour, the camera setting were the same for this test i.e 0.5 seconds @ f22 iso 100. The same processing was used to produce the video.

Uploaded to youtube as a HD 1080 video

140 thirty second exposures on a Canon 7D an 10-22mm lens taken from Cemlyn Bay on Anglesey in N. Wales. Processed as a timelapse to see the movement of the stars and the police helicopter which was searching for someone. It is uploaded to youtube at 1080 HD video for more detail.

The final star trail photograph looks like this:

The Cemaes village is located on the northern edge of Anglesey in N. Wales. The harbour is the focal point of the area and can be viewed here as an interactive panorama

Cemaes Bay Harbour Panorama

To view the interactive panorama click here

The first tests with a Merlin motorised astronomy pan/tilt head controlled by the Papywizard software and Nokia N800.

The Merlin motorised pan/tilt head was originally designed for Astronomy and has been modified for panoramic photography. A bluetooth module connects the head to a Nokia N800 pda running bespoked software called Papywizard which controls the head and the camera during pre-programmable panoramic sequences

The main source of information regarding this system can be found on the Autopano forum

Cemaes Bay Harbour Panorama

To view the interactive panorama click here

Apple iMacs are well known for having clear and sharp displays but the latest generation of flat screen iMacs appear to have little or no calibration options. That is, not unless you know how.

Firstly, when you take your iMac out of the box, switch it on and are dazzled by the sharpness and clarity of the screen – trust me, it’s an illusion and the screen is likely to be far from ideal for working with colour in processing applications such as Photoshop. Yes, there’s a screen calibration facility built into the System Preferences > Displays > Color tab but good results are difficult to achieve.

Here’s a quick and easy way to get very respectable results:

1) Turn down the brightness either by using the keyboard top row buttons, or in the Display Preferences tab – the iMac comes shipped with the brightness set very near to the top of the scale which enhances the appearance of clarity but also reduces the life expectancy of your screen. A good starting point for the brightness setting should be between 40-50% but this will vary depending on the ambient light in your room and the age of the display.

2) Turn down the contrast to it’s lowest (normal) setting. The strange thing with the latest version of Mac OS (version 10.6 Snow Leopard) is that the contrast control slider is not in the Display preferences pane. You’ll find it in System Preferences > Universal Access > Seeing tab. By default it will be set at about 25% – turn it right down to the left.

3) Visit www.bergdesign.com/supercal/ and download SuperCal. It’s a little shareware application that’s free to download and if you like it, you’re encouraged to make a modest donation to the developers. Move the SuperCal application into your Applications folder and launch it. The software is really easy to use and is self explanatory, and it will guide you through creating bespoke and accurate Red, Green and Blue profiles as well as setting the gamma point.

Tip – when setting the gamma, tick the box that says ‘Native’. Modern iMac displays use a setting of 2.2 as opposed to the older iMac screens that worked on 1.8

4) Once you’ve been through the SuperCal routine, you’ll be prompted to save the profile that you’ve created and the screen should automatically default to this profile – give it a sensible name like ‘Supercal1′ or something.

5) If you now go back to the Displays option in System Preferences and look at the list of available screen colour profiles, your new Supercal1 will be listed. You can play with and try different profiles, but the one that you have created is likely to be the most appropriate one for your computer in your environment.

6) Repeat this short process every time you make any significant changes to your computer setup including moving the machine, redecorating the room or fitting new bulbs or light fittings. Also make a habit of recalibrating every month or so if you’re serious about colour representation.

That’s it. The whole process takes a few minutes and the results are excellent. You’ll immediately find pale blues and light greys on your screen in web browsers and finder windows which were never there before, and your desktop picture is likely to come alive with detail that had previously been lost in dark over-contrasted shadows.

Using SuperCal gives much better results and is easier to use than Apple’s in-built calibration system.

Credit for this excellent tutorial goes to

“Steve – not a pro, just trying make the best of what I’ve got.”,

my thanks for the excellent addition to the website

There will be a partial eclipse of the moon on New Years Eve, December 31st 2009. Because of its timing, it will not be visible in North and South America, but will be visible over most of Europe, Africa, and Asia IF the clouds stay away.

Partial Eclipse of the Blue Moon on the 31/12/09 19:22

The event will also mark the second full moon of the month in North America, thereby claiming the title of a “blue moon.”

Since it is a partial eclipse, the moon will just touch the darkest part of the Earth’s shadow, never becoming totally obscured. It will, however, be deep enough into the shadow that shading should be visible.

As the sun sets in the southwest, the full moon rises in the northeast.

For the eclipse, the duration of the partial phase will last about an hour, while the penumbral duration from beginning to end will run about four hours and eleven minutes. Penumbral contact will begin at 17:17:08 UT and umbral contact at 18:52:43 UT. The moment of greatest depth of shadow will occur at 19:22:39 UT, 31 December 2009.

all times are UTC (GMT)

The UK weather forecast for Thursday evening is patchy cloud but fingers crossed the event will still be visible

The Quadrantids Meteor Shower 2010

A single Quadrantid meteor can be seen on the far right of the image. Taken at location 53.409319,-4.516483 on 01/04/2010 / @ 03:27:10

Typically, 40 or so bright, blue and fast (25.5 miles per second) meteors will radiate from the constellation Bootes, some blazing more than halfway across the sky. A small percentage of them leave persistent dust trains. This shower usually has a very sharp peak, usually lasting only about an hour.

Sky maps created with Stellarium from www.stellarium.org and Starry Nights

The particles that cause the Quadrantid meteor show originate from the asteroid 2003 EH1 an asteroid that is probably a piece broken off of an obsolete comet. Since the orbit of 2003 EH1 is highly inclined to the orbit of the Earth, the Earth passes through it very quickly. Thus, the Quadrantid meteor shower is an extremely short one, lasting only a few hours.

In 2010 the Quadrantid meteor shower is predicted to reach a peak in the early hours of January 4th but the shower will be visible between January 1st and January 5th 2010.

Check the weather forecast

For more information on the meteor shower this site is full of information.

Star Trail photography using a Canon EOS 7D camera and Canon 10-22mm lens

Cemlyn Bay on Anglesey in North Wales, Wylfa nuclear power station is on the right hand side

The Barn Owl Centre in Gloucestershire

St Bartholomews Church in Churchdown, Gloucestershire

Initially the Canon 7D produced some slightly disappointing results with gaps clearly visible between the individual 30 second exposures. The stacked exposures have been processed by the freeware software StarTrails

It appears that each 30 second exposure was taking 32.6 seconds to complete. This 2.6 seconds delay between frames was giving the gaps in the Star Trails.

This test image of 25 exposures looks good at web resolution

but at full resolution gaps are clearly visible between exposures

Checking on the Flickr StarTrails and Photography-on-the-Net forums gave me some pointers and after turning all the noise reduction functions off, disabling Silent Shooting mode I have be able to reduce the delay between each thirty second exposure so that when this image of 74 exposures

is viewed at 100% the gaps are significantly less.

Further testing on the Canon 7D has shown that the 30 second exposure setting on the camera is actually opening the shutter for in excess of 31 seconds.

The sequence below is of a clock on my laptop with the 7D programmed for  continuous 30 second exposures which illustrates the length of the 30 second exposures. What should of taken 8 x 30 seconds** took 8 x 30 seconds plus an additional 19 seconds.

** plus a small time for the mirror and shutter to recycle between exposures, maybe 8 x 0.25sec

[Show as slideshow]

 

Some tips I’ve picked up that work for me

1. I use the stacking method for star trail photography. In light polluted areas the technique allows me to get a good exposure of the stars and sky and allows me to ‘paint’ the foreground with light or flashguns to highlight something of interest in the foreground. If I used the single long exposure technique the sky would end up very overexposed from light pollution.
2. Typical sessions will consist of 200-300 30 second exposures taken at iso 200 f4 using a wideangle lens on the Canon 7D.
3. Use the aperture to define how many of the distant stars appear in the final image and also how much of the image is in focus. It is worth calculating what the optimum hyperfocal distance is for the aperture you are using so that you know infinity is in focus and some of the foreground will also be sharp. With wideangle lens focussed at 10 metres you will get a DoF from 5m to infinity with the lens stopped down one or two stops (f4-F5.6).
4. When you have the right aperture use the shutter speed to control any light pollution; close to cities you can use shorter exposures without losing the stars being captured, in darker regions you can use longer exposures.
5. I try to keep the iso setting to 400 or less to minimise the sensor noise
6. Always take dark frames before AND after you do the main sequence of images. Adding the dark frames into the star Trails program will reduce the effects of sensor noise.
7. I normally shoot in RAW mode to give me the control over the quality and finish of the image. Using JPG mode is fine and certainly means less post processing of the files but it has some limitations. Using RAW also means the White Balance can be adjusted later in the RAW processing software. I do manually set the camera White Balance to 5800k so that it is constant through the sequence.

This site contains a lot of very useful information and is well worth a visit

This short video was taken using the Canon 7D fitted with a Canon 600mm f4 prime lens and Canon 1.4T/C. It was shot at iso 1600 after I gave up photographing because of the low light at the Spinnies Nature Reserve.

Here’s to the crazy ones.

The misfits.

The rebels.

The troublemakers.

The round pegs in the square holes.

The ones who see things differently.

They’re not fond of rules.
And they have no respect for the status quo.

You can praise them, disagree with them, quote them,
disbelieve them, glorify or vilify them.
About the only thing you can’t do is ignore them.

Because they change things.

They invent. They imagine.
They heal. They explore. They create. They inspire.
They push the human race forward.

Maybe they have to be crazy.

How else can you stare at an empty canvas and see a work of art?
Or sit in silence and hear a song that’s never been written?
Or gaze at a red planet and see a laboratory on wheels?

While some may see them as the crazy ones, we see genius.

“Because the people who are crazy enough to think they
can change the world, are the ones who do.”