Part one (air space #44) covered the construction of the stand-alone camera module or carrier and showed it mounted on my Falcon ready for action.  Up to that point all of the skills required had been familiar ones honed over many years.  However, the next stage was for me new ground.  Of course, that very fact  was a powerful reason for exploring aerial photography.  We are always looking for ways of pepping up our experiences and fortunately aeromodelling is rich with different avenues to explore in that quest.  

In part one of this article I said that my objectives were:  

First, I wanted my mount to be a self-contained module.

Second, I wanted the module to be easily transferable from aircraft to aircraft.  You will also recall that I anticipated vibration would become a problem and it did!  

The first objectives were achieved.  The design lends itself easily to transfer between aircraft.  It is very adaptable to minor modifications and though I have not yet attached it to an aircraft without wing dowels, I anticipate no difficulty in making the small changes required in the suspension of the module.  

I have made two photographic sorties so far and each one captured images of our club site  - http://www.scaleglidingnlincs.org .  I used the Fuji Nexia camera for the first sortie and when I removed the film from the camera I got my first surprise.  The camera is an APS format which I had innocently thought was just a variation of 35mm - how wrong I was.  Because the film stock is much smaller than 35mm I had to take it to a shop for developing and printing.  The nearest shops from my home are 8 miles away - yes eight miles.  The prints revealed that my vibration fears were justified as a look at this picture reveals.

 

I decided to buy another cheap camera (not much more than the cost of a decent servo) but this time getting a 35mm which would enable me to develop the films and view the results an hour or two after the sortie.  So off I went to Argos and brought back an Olympus Trip MD3.  I had made certain that the MD3 would fit inside my camera module. The MD3 proved to be a better tool as the shutter button was taller than that on the Fuji and was much easier to operate reliably using the remote servo.

Olympus MD3 and module

Back we went to the field for a second sortie.  This time however I had first installed some crash rubber pads behind the module aiming at reducing vibration that way. 

Anti-vibration pads

I did not expect that this would be totally successful so I planned to take two sets of photographs.  I would take one set with the engine still running so that I could open up and get back some altitude.  If that worked then it would be the most useful method.  The second set would be taken after climbing the Falcon to a fair old height, cutting the power and taking pictures on the glide back to earth.  As the glide angle did not seem to have been steepened to any extent by the payload, I would have plenty of opportunity to get several pictures.

 

This picture above left, was taken with the engine still running and though the pads do seem to have reduced the effects of vibration compared to the earlier picture shown above right, it has obviously not been eliminated.

These three pictures (above) were taken on the glide and are clear enough to be able to pick out the feeble little figure flying the aircraft.

So I have confirmed what most exponents seem to say is the best technique and that is taking pictures on the glide.  There is just one snag with that.  On the day I took these shots we had a breeze gusting occasionally to about 12/14 knots.  That is quite stiff for a gliding Falcon which is not the most penetrating of aircraft.  I got so carried away with the job in hand that almost too late I remembered that I was executing a dead stick approach and was too far downwind for comfort.  Our club site is flanked by two fairly wide rivers and my aircraft was beyond them.  If I failed to make the landing strip then I knew that I had a 10 mile drive via the nearest bridge and back to the adjacent spot on the far bank. I have done that once and did not wish to repeat the exercise. Fortunately I succeeded in coaxing the model over the hedge and just into the very edge of our field where it disappeared in the longer grass.  It came to no harm.  

In conclusion I would say that the module is fine and it does enable one to mount a camera neatly and quickly.  I believe that the best platform will prove to be an electrically powered model furnishing the ability to take pictures on the glide as well as being able to return to powered flight at will.  A brushless motor would vibrate at frequencies so high that pictures would not suffer, I speculate.  The other point, to which in Part 1 I said I would return, was the angle at which the camera was declined.  My experience suggests that I have got the angle too steep and that the wedge shaped wooden fillet needs to be narrower at the top.  Perhaps the best way would be to simply mount the camera so that it looks vertically down capturing a “mapping” type image.  In any case I do believe that it would be best to build a dedicated, electrically powered model.  The question is whether to find an existing design (someone must have done it already) or whether to build one of my own.  We’ll have to see which but first I have two other models to build.

Photographic processing discussion.

I wished to save money and time on the way to getting my photographs and if you fancy doing the same, then I recommend you read this.  The outlay on a scanner may rule it out but these days many people already have these machines.  My own is a dedicated film cum colour slide scanner made by Hewlett Packard though there are others.  

I have always done my own developing and printing.  Today I no longer use an enlarger but develop my film and then scan it into my computer.  The pictures below show the simple equipment needed to develop the film which task takes no more than half an hour.  In addition to the bits shown, you will need a reasonably accurate thermometer obtainable from most photographic dealers.

35mm developing tank and measuring flask

The final picture shows the C41 developer and fixer kit which enables you to make up the developer and fixer solutions for about a dozen films.  The cost per film then for chemicals is about £1 and you get the negatives in about 2 hours allowing for drying time.

 

The technique is very, very straightforward so I will not describe it here.  Clear instructions come with the C41 kit.  

Grapher

September 2001