We discussed colour temperature for the whole evening, and it was good to chat more about something which I had a basic understanding of before, but had always struggled a little with. I used to shoot using daylight WB (White Balance) and hope that the photo worked out OK! Lately I have been using RAW conversion (I have taken RAW files for years but not used them much) and have found a better workflow which involves me doing some simple post processing in the RAW converter to get a better image and also to fix up the WB which can make a surprisingly big difference to an image!
The discussions in class focussed on the idea of 'get it right in camera' and thus suggest using the K setting (for Kelvin) on the WB selection to tweak the WB in the jpg out of the camera and thus decrease the need for fiddling with raw files. It also improves your knowledge and understanding of how to better use Kelvin (ie to warm up an image or cool it down).
Likewise, the tutor Steve suggests we use total Manual on our SLRs. I generally shoot in either Av or Tv so it is a change to shoot in M. You have to think a bit more but the idea is that we will become better photographers in the process. I do like this thinking and it does require more time & effort which would probably also be good for me...
The diagram below shows the Colour temperature scale, with low numbers representing warm colours (candle etc) and high numbers representing cool colours (eg the deep shade of a building).
Taken from this site.
This week (4) we discussed Flash.
Next week will be practical use of flash, so there was a lot of talking tonight, but I found it very useful. We discussed which mode to use (camera and flash) when using an external flash:
Av + TTL: Not a good idea as the shutter speed might go above the sync speed.
Tv + TTL: Better, however this method will mean no choice of DOF and thus less creative control
M + TTL: This is the gold standard. Total control - you set the shutter speed (usually around the sync speed of the camera, mine is 1/250), and then choose the aperture for the DOF you wish to have for your subject. The TTL will fill in the rest.
We discussed using Flash Exposure Compensation (FEC) which usually requires the flash to be turned down 1 to 2 stops if it is being used as fill flash. Another way is to use a diffuser, either the built in one on the flash head, or a Stofen, or a Gary Fong like I have (though have found to be a big bulky some of the time). We also discussed using other methods such as pointing the flash at a ceiling or wall (if it is white and close by) and this will also both diffuse the light and decrease the power.
Then we got into the formulas and discussed guide numbers and how to calculate it for your flash (which I will get onto soon). And then just using the simple formula:
GN = F/D
ie. Guide No. = Fstop/Distance
So decide what your choice is - either you have a specific fstop in mind or you are limited by distance, and then just use the formula to work out what the other variable should be. Don't forget if you shoot off a ceiling or wall these also are included in the distance (ie it's total distance from your Flash to your Subject). That also means that you can set your flash up and then know you can move around your subject as necessary (assuming flash in one place). This was super useful for me so I'm hoping to get some time on the weekend to play with my flash a bit more.
We finished up the evening talking about studio lights and what sort of different things you can stick on the end (soft boxes, spill dishes, snoots etc). A very informative evening all up!
A quick example below of my first experiments using second curtain flash and slow sync.
f/5.6, 1/4s, on camera flash, ISO 100
Learning to fly
No comments:
Post a Comment