Tuesday, March 22, 2011

Working with Flash

Okay so I attended a CPW workshop on flash photography -part one. Many photographers consider flash as the enemy and where ever possible avoid using it. Oh so lucky to have the right light all the time! No doubt, the pop up flash and the flash you place on your DSLR can be unflattering however correct placement and use of this can reap rewards. So too can you improve your photos by taking the Flash off Camera. The thing is there is a bit of Maths involved and you need to know your aperture (f stops). So here we go;-

1.0,1.4, 2.0, 2.8, 4, 5.6, 8, 11, 16, 22, 32 
f/stops are a bit confusing because the numbers appear so arbitrary. This is the standard sequence of f/stops from f/1.0 to f/32. Although it may not seem intuitive at first, in this sequence the f/1.0 setting lets in the most light while the f/32 setting lets in the least. Also, each of these f/stops has precisely the same halving/doubling of light let in.


As Glynn from CPW said think of Aperture as the dimmer  and the higher the number the less light on the sensor of your camera. Your shutter speed controls the ambient light (the Scene) and of course the flash lights your main subject.

Camera flashes normally provide specifications for Guide Number (GN) as a guide to the flash power and its distance capability. Specifically GN is a tool for manual flash power levels.  Typically the aperture for any particular shot can be worked out by dividing the GN by the distance from the object you are shooting. Aperture = Guide Number / Distance

So by rearranging the variables we are also able to determine the following;

Distance = Guide Number / Aperture

Guide Number = Aperture x Distance

If for example, if  the GN is 32 and you place the Flash 8 Metres from the subject then the Aperture will be f/4.   The advantage of knowing this Guide Number constant is that if we then move the light to be 2 metres from subject, then it tells us that GN32/2 metres= f16 will give us correct exposure there too. All Guide Numbers are based on ISO 100. So if you increase ISO what are you doing? You are increasing the sensors sensitivity to light and by each step up in ISO you are effectively increasing by a stop. It is at this stage that you realise a calculator would be handy and this is where a handy app on an iPhone is useful. Thankfully most Photographers own an iPhones and there is a  handy app PhotoCalc which allows you to do the sums changing the variables and also if you are wanting to decrease flash power, increase ISO or use incremental fstops. Whilst this app is handy it is best to understand the concepts. So you know the concepts but nothing beats actually doing it and experimenting with the placement of the flash and dialling up or down your f-stop. Having been on  a couple of workshops I have also noticed subtle differences between Nikon and Canon and from Canon to Canon. Some of this may be to do with the LCD display settings on the back of the camera. One thing you have to watch is the placement of the flash making sure you do not get the light reflected back at the camera. It would seem in most situations placing the flash 90 degrees to the subject works the best. Start practicing with one flash then move up to two or more.

 

Sunday, March 20, 2011

Can't have too many Cameras!

I was lucky to get two cameras from Su's mother, Pam, a Voightlander and a Olympus Trip 35mm that belonged to her late Husband. Recently via eBay I purchased a Kodak Box Brownie Flash II.
Voightlander is reputedly the oldest names in cameras. In 1956 they sold out to Carl Ziess Foundation. In 1972 Zeiss/Voigtländer stopped producing cameras, and a year later Zeiss sold Voigtländer to Rollei. On the collapse of Rollei in 1982, Plusfoto took over the name, selling it in 1997 to Ringfoto. From 1999 until the present time (2010), Voigtländer-branded products have been manufactured and marketed by Cosina. (source Wikipedia). The one I have, I have not been able to positively identify but I think it is of the Compur folding range made in the 1930's(guess).
The Kodak Box Brownie Flash II camera I have is about 1960's era and can remember my father having one. The Box Brownie cameras put photography into the hands of the people and was a simple camera that even children could operate.It was made for 70 years from 1900 and about 125 variations of the first camera. I bought mine on Ebay for about $30 and intend to use it on themed photoshoots I have in mind.
The last camera is a Olympus Trip 35   and was made from 1967 to 1984 and in the 70's was made famous by David Bailey in a serious of advertisments. Over ten million were sold(source Wikipedia) so I don't consider it worth a lot but handy to have anyway. Who knows might get a roll of film and get real adventurous.

Another Gadget....


Okay so I have been very slack and not posted anything for ages. In  that time we have had a cyclone up north, an Earthquake in Christchurch and an Earthquake and Tsunami in Japan. Quite depressing really that with travelling for work meant I kinda lost my groove. My good friend Melanie has recently posted on her blog with renewed vengance and she spurred me into resuming my posts.
As many of you know I am an avid eBay watcher and manage to fritter my money away on the odd photography gadget. My lastest aquistion is a LED ring light a bit cheaper than a ring flash or Macro Flash and must say I am impressed. Some of you may remember my purchase of a LED light about a year ago. I must say I like this form of light as very little heat, bright and white. Of course I had to test it out.....