I finally got around to hacking a Philips SPC 900 to enable it to take long exposure images suitable for astrophotography. The modifications are fairly well known. The approach I took is a mixture of the http://www.boltonastro.org.uk/Members%5FArea/Projects/spc880conversion.pdf from Bolton Astronomical Society and http://www.yesyes.info/index.php/diy/philips-spc900-webcam-lx-and-ampoff-mod/ .
The circuit between both approaches is roughly the same, I followed the circuit in the former. The modification allows the camera to be switched to a long exposure mode via a switch. The switch can be triggered over a serial port, so I added a USB to serial adaptor and a USB hub (both from ebay) to the unit to allow control from a computer and have just one cable coming from the unit. Continue reading Hacking a webcam for long exposure astrophotography
Its been a while since I posted anything here so heres a few shots that I took recently around Dublin.
Recently I bought a 5 million candle power torch for photography. The intention was to use it to ‘paint’ nighttime photos. However today I thought I’d try it out to light a boquet of flowers.
||This shot was taken of a single rose in a pint glass. In order to get
the dark background you just need to have a distant background and ensure that the torch is only lighting the target. The brighter the target is the darker the background will be. 109mm lens at f/11 to get some depth of field on the flower. A shutter speed of 1/10s is enough to show the flower well lit with the bright torch but not enough to being out any features in the background.
| Leaves have a very detailed structure that is easily missed when photographing them when they are lit from the same direction as the camera. To bring out the detail this leaf was lit from behind. 41mm f/14 1/6s. This is a detail from a larger photo, but as you can see the depth of field (even at f/14) wasn’t enough to show the whole leaf in focus. I didn’t throw the background into darkness this time, the background is just a white t-shirt!
|| I used a slightly differn’t approach on this more usual shot. Most of the light in this shot is natural light from a nearby window. Just the tip of the flower was lit by the torch. A couple of birthday cards placed in front of the torch helped block bright light hitting the leaf. 3/10s f/11 50mm.
A macro lens would have really helped with this project! However I think I got decent results with a combination of regular 18-50 and telephoto 70-200 lenses.
Last Saturday I took my first trip to Dublin Zoo in several years, and its improved vastly from my last visit. The animals have much more room to roam about than they had on my previous visits, and work is continuing to improve facilities further.
A Zoo provides great photo opportunities. One of my favourite pictures of the day was of an animal that I hadn’t seen before, a Red Panda.
This photo is almost perfect and thats frustrating! The depth of field is eactly what I wanted, 4.5 with the lens fully zoomed in. But when you use a long focal length and a small depth of field there is no room for error in focussing; in this case the little guy’s eye is just out of focus – focus is just in front of his ear!
I tried a similar picture with a Snow Owl at f/5:
Using a lower zoom the problem of getting depth of field at f/4.5 isn’t as big. This picture of the Red Panda is much more forgiving of focus.
This is all well and good when the animals are co-operative, but it was a hot day and some just wanted to hide in the grass and sleep.