Photography Trip in Notts II

Spent Saturday on a photography trip to Notts II, which I had not visited before. This was a much less ambitious trip than our attempt to photograph Gaping Gill main chamber a couple of weeks ago, and proved very successful. A really beautiful cave which I was only able to photograph (and visit) a small proportion of because we had to be out in time for our club annual dinner that evening. A return visit is planned!

Having learned from the Gaping Gill experience, I put the flashguns in zip-lock food bags to keep them dry. This caused some problems in that it was difficult to turn the dials on the top to set the auto modes, and also because the light appeared to reflect around the inside of the bags enough to fool the auto sensor into thinking the correct exposure had been achieved before enough light had been emitted. So pictures taken with the flashes on auto were completely under-exposed. I had to use them on manual, which stopped me getting pictures in smaller spaces due to the brightness being too much for the camera. I was able to use a low ISO setting and stop the aperture right down for excellent depth of field and low noise in the pictures, but the flashes had to be at least 6 feet away from the subject, and this was not possible in the confines of the scaffolded entrance shaft.

I took all the pictures on the lowest ISO settings I could get away with, after the problems with noise in the Gaping Gill pictures. One of the flash gun batteries failed early again. The Metz NiCad pack is just old and past it. I have converted the AA cell battery pack from the other flash to take NiMH rechargeable cells, and this lasted the whole trip. I think I will be cutting open the NiCad pack and replacing the cells in that with AA NiHM cells now. The slaves attached to the flashes were constantly being triggered by our cap lamps, which nearly blinded me when I was putting one flash face up on a rock and it went off about 2ft in front of my face! I think the LED lamps we are using these days are far more prone to triggering the slaves, as we never used to have big problems in the past. This was one reason why the old NiCad battery pack ran down. Then every time we got it to recharge the flash ready for another shot, it would get triggered by accident, and we had to wait another few minutes for it to recharge the flash again.

Here are a couple of pictures from the trip (quick roughs, as I have had no time to balance the levels or anything yet).


Curtain in Curry Inlet

Stalactite in Main Passage

I was assisted by club members Caroline F., Annette B., Tonk and Dave in taking the pictures (thanks very much folks).

Trip to Photograph Gaping Gill Main Chamber

Armed with a couple of Metz hammerhead flashguns recently purchased on Ebay, I organised a trip to Gaping Gill last Saturday to attempt to photograph the main chamber. This was primarily a learning trip and we attempted to take a series of images which can be layered together to create a single picture.

We had a few problems! It was very wet for a start, so spray in the air made things difficult. One of the flashguns stopped working early on, possibly because of the damp. Also I was trying to fire the flashes using slave units triggered via the built in flash on the camera (covered with some PVC tape to stop the flash illuminating the picture). This was not powerful enough to trigger the flashes when not in line of site at the far end of the chamber. The tape did not block enough visible light either, so parts of the camera housing were illuminated in purple (I had no black tape to hand) and reflected in the inside of the housing glass. However, enough images were captured to create some pictures. Here is a quick rough edit done on Monday night:


Gaping Gill Main Chamber

The main points learned from this trip were:
1) I really need to use a tripod for these set ups. My waterproof housing prevents the camera being mounted on a tripod, so I hung the camera from a rock using the housing straps. But this meant the shots all had to be aligned by hand and I could not see the back of the camera easily, or adjust the settings without moving it.

2) Even these big flash guns are not very bright in such a big chamber! The flashes also need to be sealed in bags to keep the water off them.

3) The noise on the pictures taken at 400 ISO is quite high. I should try and take pictures at 200 ISO if at all possible.

4) Care needs to be taken not to over-expose people using these big flash guns. The cave looks dark but the people are burnt out in most shots.

5) I need a more powerful and better masked flash on the camera to trigger the slave units without reflecting the inside of the housing. (I have since bought a cheap flash gun on Ebay for this purpose. All my existing guns have high voltage triggers, which can damage digital cameras. This one was listed as low voltage on a website I found which has a list of flash guns and trigger voltages.)