Showing posts with label Nikon D80. Show all posts
Showing posts with label Nikon D80. Show all posts

Sunday, February 3, 2013

Camera settings for KAP

The biggest problem with Kite Aerial Photography is that the camera is moving all the time, sometimes to a scary degree. More than once I have seen the camera do the full 360 over the kite line.

So you must use a fast shutter speed. I use shutter priority and routinely set it on 1/2000th. That's Tv on Canon and S mode on Nikon. In light and steady winds you could use a slower shutter speed.

With the Canon S100 I also choose Auto ISO to prevent underexposure on dull days. With the Nikon I use ISO200 because Auto ISO is not available in S mode.

In shutter priority mode the camera chooses the aperture for correct exposure. With the shutter set at 1/2000th the aperture will most likely be wide open. This is OK because the subject is usually far away so depth of field is not an issue. Even with wide apertures, like f/2, everything will be in focus.

I'm undecided about Image stabilisation at this stage having tried with and without but not seen any difference.

I have the intervalometers set at one shot every 5 seconds on all three cameras.

Saturday, January 12, 2013

Nikon D80 AuRiCo rig

Once I knew my kites could lift the SLR it was time to add some AuRiCo.

This rig was to be another limited pan, manual tilt style, which involved some very simple shed tinkering.

Just had to bend up some aluminium as a pan bolt bracket and rivet it on to the top U. This bracket steadies the pan bolt which is no longer solidly fixed to the top U but rotates.

The bracket also acts as the pan servo mount so I had to think about how far away from the pan bolt the servo needed to be positioned. That distance depends on the thickness of the servo and which gear cogs are used.

Nikon D80 SLR AuRiCo autoKAP rig - 1195g

To keep the rig as simple and light as possible I used velcro and rubber bands to hold the AuRiCo and batteries on.
As the pan servo is only rotating the rig it doesn't need to be too big or securely bolted on. I started with a Futaba S3003 but ended up using Turnigy 380MG stuck on with double sided tape and cable ties. Although the servo is moving over 1kg of camera and rig there is a lot of give in the picavet suspension setup.

You can see in this video how the load transfer from servo to rig is quite spongey which reduces strain on the servo. The servo moves the picavet on its lines first then the rig swings around.

Nikon D80 KAP shots




Thursday, January 10, 2013

Nikon D80 SLR manual rig

I recently upgraded to a Nikon D7000 for underwater photography so my original SLR, a Nikon D80, doesn't get much use these days. To reward the D80 for reliable long service and paying for itself many times over I thought it might like to go flying.

It's not the ideal KAP camera being quite heavy (672g body + 202g 18-55mm lens = 874g all up)
and it doesn't have an intervalometer but that didn't stop me. James Gentles makes a lovely little device called GentLED-AUTO which is an IR remote intervalometer weighing just 20g. I just happened to have one sitting around so it was time to give SLR KAP a try.

First step was to make a basic manual rig just to see if my kites could lift it.
I bent up some aluminium to make a rig similar to the vertical style Aurico autoKAP rig for the Canon S100. But this design, a single vertical support with an L bracket to mount the camera, was way too flexible for the heavier SLR. The spring like flexing would have had the camera bouncing up and down continuously.

Nikon D80 manual rig - 1090g

So I had to revert to the tried and tested double U style. This allows a light and stiff rig to be built using the minimum of material, but it means I needed to balance the camera in the bottom tray carefully following James Gentles guide, which I find much trickier than building the vertical style rig.

The bottom U tray needs to be wide enough, front to back, to accommodate the camera mounting bolt and the pivot holes on each side which are at the centre of gravity for the camera. With this camera/lens combo the centre of gravity is 24mm forward of the camera mount hole. The bottom U needed to be 40mm wide. The top U only needed to be 30mm wide to be stiff enough.




Amazingly the wind was perfect for a test fly on the day I made this rig. Sunny with a smooth onshore 12kn and the Levitation Delta had no problem lifting it all as shown in this video.

I was really pleased with the image quality compared to the Canon S100 partly because the heavier rig isn't blown around by the wind as much.

I have begun to realise that lighter rigs suffer from blow back resulting in angled horizons or more/less tilt than expected. I'll talk more about blow back soon.

Here are KAP shots using the D80