OVER 2 YOU, 157 (25/11/03)

AERIAL VIEWS

Can anyone suggest a way of taking an aerial photograph of my property, preferably using my own digital camera? Would such a thing be possible, using a tethered balloon or perhaps some sort of radio-controlled aircraft?

Peter Mitchell, via email

It is feasible to take photos from a radio-controlled aircraft; I have done this with a 6-foot span plane using a standard 35mm camera, operated by a servo.  However such aircraft require some skill to fly safely and cannot be considered as toys, safety considerations are critical. A local model flying club would be able to teach the skills needed and also enrol you into the British Model Flying Association (www.bmfa.org), which provides third party insurance cover.
 

Over flying a built up area is not permissible from a safety point of view, however if the property is in a rural location and the landowner gives permission, there should be no problem.
Chris Boll, via email

I suggest Aerial Close-up Limited (http://www.aerialcloseup.co.uk/), which has a digital camera on a huge long pole which is as near aerial as you can get without an aeroplane.
Robert Marchant, via email

It certainly is possible, using Kite Aerial Photography (KAP). There's quite an active community of people interested in KAP. Peter can see photos I have taken of my own house at: www.zenonic.demon.co.uk/kap/gallery3.htm For an extensive discussion of KAP, including lots of photos and detailed information on what's involved, see Cris Benton's website at: http://arch.ced.berkeley.edu/kap/kaptoc.html
David Mitchell, Totnes, Devon

Skilled kiters sometimes use this technique. You can post a question and get more information on the Flexifoil kites website at: http://www.flexifoil.com/
Simon Michell, via email

Sawston Village College has a link to the NASA site for building Kite Aerial photography kits at http://education.ssc.nasa.gov/kap/kap.htm. All you need is some wood, a Kite and an instant camera and some rubber bands.
Tim Chapman Cambridge

For info on aerial photography using kites have a look at: http://www.harb85.freeserve.co.uk/
David Haverty, Newbury

Peter can buy a ready to fly model rocket with a camera, they’re available from many toy and hobby shops. It’s a bit hit and miss and the photos are low resolution but it’s fun! Easier still, go to www.multimap.com and click ‘aerial view’. Press ‘overlay’ and roads appear under your mouse as you move across the image! It’s fascinating and I’ve ordered a high resolution print of my property.  
Dr. Nick Slaymaker    

The Water Rocket Site at: http://ourworld.compuserve.com/homepages/ pagrosse/h2oRocketIndex.htm includes a description of using a home made water rocket to take aerial still photographs and short videos. 
David Mack

There are various options to take a photograph of your own property, none of which are very cost effective, or you can do what one crazy American did. Obtain several meteorological balloons, tether them to a sunbed, float over your property, take photo of your house (and the neighbours), then with an air gun shoot out the balloons one by one bringing this craft slowly to the ground!

Lyndon Yorke. Via email

I suggest getting in touch with the Chief Instructor of your local flying club and talking the matter through with him. If agreement can be reached, the CFI will know what is allowed, this method would enable good pictures and many changes of mind with none of the problems of remote control of a camera attached to a balloon, model aircraft or a kite. There is nothing like being able to get an aircraft into the right alignment at the right height on a nice day. If Peter Mitchell puts his effort into working out which views he wants in each shot, taking account of the position the Sun, a pilot will be able to sort this out for him with minimum trouble.

A second camera, possibly a normal SLR with a choice of zoom lens and lens hoods might be wise and shutter speeds of about 1/250 sec.. A large format camera would be even better, but it is also possible that the pilot will have experience and suitable photographic gear. A figure of £150 to £200, say,  might be a good discussion starting point for say a forty minute flight in a light high wing monoplane.

Alan Lovegreen, Lochwinnoch

Aerial photography from radio-controlled model aircraft was pioneered in the U.K. over 40 years ago (see "Aeromodeller" July 1962). The results were rather fuzzy and suffered from the vibration from the engine used to power the 'plane.  Since then gliders and electric-powered model have enabled higher-quality results, and the advance of radio-controlled model helicopters has increased possibilities. There are several Websites which detail current experiments in this field, including http://www.hicam.com.au/links.htm

Regarding the use of a digital camera, a limitation is the need to arrange to trigger multiple shots and at precisely the right time (I have an elderly Ricoh auto-half clockwork-driven camera which is ideal). Also do not expect to teach yourself to build such a model aircraft cheaply, or achieve satisfactory results without much pain and experimentation, and there may are noise and safety considerations.
Peter Scott, New Milton

If you care to visit our web site at www.skyscan.co.uk you will see that our photographers use a range of different platforms to mount aerial cameras (whether digital or not), these include remotely controlled masts, balloons, model helicopters as well as conventional light aircraft, helicopters and satellites.In the past we have been known to let the client handle the camera controls although for speed (and therefore client costs) it is best to allow the professional to work efficiently especially when there are weather variables
to consider.

In addition to undertaking commissions, we also have a large stock aerial photo library and have a unique service to locate aerial images for a variety of purposes including historical imagery for land investigations and boundary disputes.
Brenda Marks, Library Manager, Skyscan Photo library, via email

ROLLING COUNT

I am trying to set up a "rolling count" formula in Excel whereby a column of movements in daily stock index data is analysed for the frequency of particular events. The normal COUNT function works with a range of data set by the user but I wish the formula to perform a rolling analysis on a column of data, for example, on a moving 4-week basis. Any ideas?
Mark Wright, via email

Use the OFFSET function e.g. =count(offset(c4,1,0):offset(c4,5,0)) This assumes that you want to count the 4 cells below c4. As you get the next set of
results, you insert a row below c4 and enter these new results in c5.If you want the formula at the bottom of the column, add a minus sign to the number in the middle of the brackets (the 1 and the 5) and insert a row above the formula. Excel help explains this function very well.
Pete Phillips, via email

Excel can be automated by the use of Visual Basic for Applications (VBA). Either simple macros or complex scripts can be written. Assuming a recent version of Excel is being used the VBA editor is under the Macros Menu.

Roy Varley, via email

CAN YOU HELP?

Can anyone suggest software that will automatically generate for printing, a set of 35mm by 45mm passport size photos? My Adobe, Coral, and Ulead programs do not seem able to do this.

Colin Harris, Rugby.

I have started to research my wife’s and my own family histories. I would be grateful for recommendations for suitable software, for a complete beginner to use, particularly when researching information obtained from Public Records Offices etc.

Robert Russell, via email