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polo
08-03-07, 17:05
Hi guys,just a quick question,
Whats the best way to use coloured filters? I have Red,Blue,Orange and a paler Orange/Yellow. My boyfriend bought them for me for christmas and i was really looking forward to using them but i'm at a loss for ideas.It seems a shame to let them sit in my bag and go to waste as they're good quality and brand new!:(

John
09-03-07, 16:41
There are filters which are mainly used for black and white photography and filters which are primarily used for colour photography. It seems to me that you have the former type of filter. Here are a few comments on filters for black and white photography.

These filters lighten objects of their own colour and darken objects having a complementary colour. By way of examples

A red filter would darken a blue sky making it almost black and thereby greatly emphasizing white clouds. It can be used during the day time to simulate moonlight effects.

An orange filter would produce less exagerated effects darkening a blue sky to something like a mid gray whilst still emphasizing the clouds.

A yellow filter has similar effects on blue skies and clouds but the effect is much less obvious. Its corrects the natural tendency of film to render blue too light and thereby loosing light clouds.

A green filter renders greens lighter and helps to separate various shades of green in a landscape. This filter renders reds darker. It can improve portraits by slightly darkening lips and pinkish skin tones.

Most filters, all of them mentioned here, require the exposure to be increased. The amount of increase is given by the filter factor which is printed somewhere on the filter ring. This is only important when you set the exposure manually. If you are using auto exposure this will happen automatically.

polo
09-03-07, 16:50
Thanks alot for those tips, i'll give em a go. Cheers, Polo

robski
09-03-07, 16:53
As John has stated these filters were intended for film. Part of the problem with using them on a digital camera is the auto white balance. You would need to defeat the auto white balance. To be honest most of these effects can now be done at the post processing stage.

polo
09-03-07, 17:23
Hi Rob, I still dont even fully understand custom white balance like when they say you should carry a grey card with you and get your readings from that. Could you enlighten me? I feel pretty stupid asking this question as it's probably one of the first things you learn about! Cheers

inacar
09-03-07, 18:17
I know this is probably a stupid question, but does the UV filter effect the picture with the white balance as the others do?

somert8
09-03-07, 20:54
Hi Rob, I still dont even fully understand custom white balance like when they say you should carry a grey card with you and get your readings from that. Could you enlighten me? I feel pretty stupid asking this question as it's probably one of the first things you learn about! Cheers

If I may say polo,please don`t feel stupid asking questions because you are NOT,I feel that way sometimes but nobody knows everything,and we are always learning no matter what the level of experience,this is what these forums are all about.I`ve learned more from photography forums than reading 10 book`s on the subject.
I struggled on white balance,but my biggest hurdle was aperture,basically its about background focus,though (as always!)there is more to it.
As for white balance try your camera in custom mode and go from one end of the white balance to the other taking shots and look at the results,then you can try the grey card thingy.
I hope this helps and if you want anymore help don`t feel stupid.:)

robski
09-03-07, 22:55
Hi Polo

You may or may no of noticed that the colour of daylight changes throughout the day. In the early morning and late afternoon it has a yellow cast and at midday it has a higher blue content. Digital cameras have an auto white balance mode that examines the image to determine the correct value for whites to compensate for the changes in colour of the lighting.

Basically it assumes that if you mix all the colours up it will give you a grey and adjusts the camera RGB levels to achive this. This is fine if you have a broad selection of colours. If you have a few strong colours then this fools the auto white logic and gives a bad result. Hence the grey card to get around these problems. Your notice that the colour of lighting is referred to as colour temperature. This is based on heating a piece of metal. For example if you heat a piece of steel it changes colour. At a lower temperatures it is blue and changes to red as it gets hotter and then gets to white heat.


Some light reading on the subject :D

http://www.cambridgeincolour.com/tutorials/white-balance.htm

polo
10-03-07, 00:38
If I may say polo,please don`t feel stupid asking questions because you are NOT,I feel that way sometimes but nobody knows everything,and we are always learning no matter what the level of experience,this is what these forums are all about.I`ve learned more from photography forums than reading 10 book`s on the subject.
I struggled on white balance,but my biggest hurdle was aperture,basically its about background focus,though (as always!)there is more to it.
As for white balance try your camera in custom mode and go from one end of the white balance to the other taking shots and look at the results,then you can try the grey card thingy.
I hope this helps and if you want anymore help don`t feel stupid.:)

Thanks for that uplifting message. Any time i have a question(no matter how silly)i'll remember what you said. cheers