Gels, Filters and Good Color?

 

Q. Gels and filters.   I spend a lot of time trying to get the colors I want, haven't found any great advice yet.   One effect I like is the vibrant, saturated, technicolor look.    I've had trouble doing this in digital without the aid of Photoshop, as it is easy to blow out color channels. (have had better success with slide film, where colors blow out a bit more gracefully).  What am I missing?

I also end up wanting to change the color temperature on certain areas of a subject (warmer light on the face, cooler light elsewhere, etc).  My results have been poor to date....  What gels do you find most useful, and used how?



OK, first this is subject to the camera and in camera adjustability and that goes into a what camera do you have question?  I know that most all now have settings for saturation, contrast and tone.  That's one thing, many also have some custom settings that simulate the various looks of certain filmstocks, within limitations.  No one has made a great in camera simulation of a filmstock yet, though several after market companies have done some great ones, like alienskin and exposure which is a very decent plugin if you were ever to get one (I personally never use any plug ins for any post work)  But that may well be worth a look.  However if that were useful so would making your own action in Photoshop, and it seems you are attempting to get it right in camera perhaps on a jpg file (I won't start on the benefits of raw wink ) so back to your what do you do?  well canon now offers a way to edit picture styles what this allows you to do is take an image in raw and adjust the colors in several modes Color, LAB, and tweak away till your hearts content in creating a perfect picture style for you and use that as the default for your jpgs and conversions but it only works on converting raws in DPP, if you were converting raws in acr you could make a custom profile for specific styles there as well, but again this would be an after the fact process. 

So what type of setting are best for your style?  well saturated color will go along with a boost in contrast and a deepening of colors which comes from a slight underexposure to maximize the saturation.  On a digital camera the basics of upping saturation is a good start, but rarely is high ever useful for people, same goes for contrast, but that tends to speed up the blown out color channels, so the ideal would be the use of a polarizer and or enhancing filter, both will reduce the light entering the camera and make it harder to see and focus through the viewfinder in dim conditions.  But this will get your colors pumped a bit.  Avoid the warm versions as they are helpful in adding warmth at the cost of more light and since your digital you can adjust your WB for the added warmth instead with no sacrifice of light intensity in the process. 

I also end up wanting to change the color temperature on certain areas of a subject (warmer light on the face, cooler light elsewhere, etc).  My results have been poor to date....  What gels do you find most useful, and used how?

I do this often, in fact I would say that I almost always have at least one gel if not more working on a shoot.  In the old days of astia I used a tea cloth on my mains always, and have since replaced it a digital variation that works afterwards in post.  But I still like the images to vary in temp all over and have found the best most consistent way for that to be done it first a reversal of the light temp of the main to eliminate any strange cast the modifier may have present.  Huh?  OK, I am getting to it, I am not now nor have I ever been a fan of accurate color!  I think most beauty models have been selected to have a skin tone and color that would most annoy me, and yes, I know that sounds a bit paranoid on my part, but I have it on good authority that, that is precisely the method most agencies judge beauty models by when recruiting new ones!  They know I like a challenge and get bored when everything is too easy, so they do what they can to help wink 

Now back to what I do, I know my units and softboxes and dishes and what have you, but not anyone else so I am never trusting that any of it does not have some color that I just don't like in it, so I want to use a gray card, not a 18% card designed for exposure but one that is designed for digital WB adjustment and is very likely neutral.  I use a WhiBal as they are all hand checked, and I know the owner and creator, very nice guy, very intent on having a great product!  They all have a reading of exactly the specs of the neutrality and its within a tolerance that if I could ever see I would be like superman with x-ray vision and have better things to spend my time looking at daily.  So I use that for a reference (OK I only shoot raw and am now often too lazy to really set the custom WB, I go by temp scale usually, but this gives me a good one if I need it, so do what I say not what I do, until you fully know what you do, and can do what you want wink )  So what do (or did, or should) I do?  I said I don't like it neutral, so why would I want it that way?  I don't, I want to get rid of any color cast, so if the softbox or umbrella has a yellow /green tint to it, I want to eliminate that for neutral, but I want a warmer picture and warmcards work great for video, they seemingly not so great for me in stills.  So instead I take a wratten filter, you can use a screw on filter or a piece of gel, (in fact if you can get a book or the samples of cinefoil or rosco gels it has them all just get the large 4x5 size book of samples wink ) I take the wrattan or filter or gel which is 100-400 degrees cooler than the light I want.  Why cooler?  because I place that in front of my camera and I shoot a neutral gray card, and balance for the neutrality of that, in other words set the custom WB on that image, and than (this is important) take off the wrattan or filter or gel that was in front of your lens. What this does is gives you a colorcast free light that now has the color cast you want, I took out the yellow/green from the softbox but added the - 200 or 300 degrees and when I balance for that my camera now thinks that's accurate, when I remove the gel and shoot with that WB all casts are removed but I am several hundred degrees warm, and the shot of the models face is not several hundred degrees warm as well.  This also works if your light and modifier is right but say your in a bedroom and the walls are reflecting a strange burgundy hue that is throwing off the color, you will this was eliminate the burgundy hue and still maintain a warm temperature. 

OK, before you ask why don't you just shoot the gray card and put a warming filter on if you want it war, its because I see no reason to 1) cut the light down through the viewfinder, and 2) place a cheap wratten that is now old and worn or even an expensive filter in front of a lens that had millions of dollars of research and development to make, with as few pieces of glass as possible.  wink

So now what did this do? it gave you a nice balance of neutral colorcast and warm tones, of course you can use the same concept to do other effects, on a shoot where we needed a green fluorescent lighting effect to simulate the green look, and we only had daylight balanced kinos lighting the scene, I balanced on a whibal with a magenta .30 on the lens and removed the magenta giving a green tint to the scenes and making my daylight balanced tubes look like the old cheap florescent lights, funny how that happens. 

What other gels do I use?  On lights I use a lot of different ones.  The main are 1/8, 1/4, 1/2, full cto* and 1/8, 1/4, 1/2, full ctb*, straw, 1/2 straw, bastard amber, 1/8, 1/2 magenta, 1/8, 1/2 green, pale rose, light rose, middle rose,  cosmetic silver rose, rose tint, peacock, red, orange, yellow, blue, green, chocolate, and the whole range of ND gels, etc. 

You name it I have used it including older gels that turn a strobe source into a blacklight at the expense of so much light it makes my broncolors into vivitars wink  Works though.

Now the ones I find most useful, 1/4 and 1/2 cto, I almost always have them on hair lights, and most rim lights.  1/4 and 1/2 ctb I often will have on background lights to offset the warmth I add through WB control.  I always did use tea cloths made from Lipton tea for mains but have since created a custom curve for Photoshop that has recreated it, it is perfection and is repeatable and easier to use selectively. 

Another popular thing I do now and especially in the past when shooting more sexy beach glamour for the Maxim/FHM,/Loaded type was we would always have a 1/2 to full ctb on the main strobes and balance either film or now balance for that and shoot, this allowed the subject to be shot with a WB that was adjusted for accurate (or warm in based on my reverse settings) but set with a very cold/blue light source, which allows the rest of the environment, mainly the sunset, sky, beach to go very warm in comparison.  And if we were not doing a sunset and wanted a deeper blue sky, or a bluer ocean, we would do a reverse process using 1/2 to full cto on the mains adjusting for that and shooting which made the sky/ocean go very cool and blue. 

With film in bright daylight we did use to use both daylight and tungsten with the same effects and beside the normal C.P. and ND we would simply correct out the added shift with on camera filters.  Its much easier now with digital.  But using tungsten film and shooting a day lit scene midday with a 1/4 or 1/2 warming filter on camera gave us a bluer sky and with strobes we adjusted to get the light 1/4 warmer than the filmstock which was tungsten plus the filter strength.

Another popular use of filters is creating day into evening, ctb plus a 1/4 magenta would given an underexposed ambient scene a moonlit nightime look often associated with the night scenes in film (you know the motion picture kind)

To enhance fires in a scene such as where a fireplace is lit but the typical flames are not fully glowing red on film based on the exposure settings, so using a tight grid or snoot shooting a full cto or even a piece that is orange/red striped into the fireplace creates a very warm glow that can be controlled without the need to slow down to unreasonable levels. 

And a major use on indoor hotel/restaurants and location shoots is to wrap a piece of cto on little strobes (often lumedyne heads given their tiny size at a base of 400ws) that were placed into light fixtures like lamps sconces etc on locations.  This works just as well on little vivitars or any small slave and in lamps many have used the screw in slaves, which work well but tend to recycle very slow.  What this does is it allows you to light a room with strobes and shoot at whatever given settings you choose, and still maintain a full ambiance as if the lamps were emitting a warm tungsten glow even though the lights  are actually daylight balanced strobes like the mains.  It eliminates the need to slow down or use a higher iso to get them to register brightly and add dimension and character to a scene.     

And when shooting indoors with strobe and wanting the appearance of a bright sunny or harsh daylight to be streaming in the window, we would simply adjust the inside for the temperature we liked with the strobes and blast  bright lights streaming in the windows with either cto, typical daylight effect, bastard amber for a more sunset look and feel, 1/2 ctb for a more harsh cold daylight effect and 1/2 cto and 1/2 straw tends to register as a more early morning sun. 


*

cto   - color temperature orange which converts daylight to tungsten,

depending on brand full cto will typically bring 5500 kelvin to either 2900 kelvin or 3200 kelvin
1/2 cto will typically bring 5500 kelvin to 4500 kelvin.



ctb    -color temperature blue which converts tungsten to daylight,

depending on the brand full ctb will typically bring 3200 kelvin to 5500 kelvin.
1/2 ctb will typically bring 3200 kelvin  to 4100 kelvin

here is a chart of many common conversion of color temperature and some  lens filters you may use

http://stepheneastwood.com/tutorials/images/colorfilterconversions.jpg

 

 

 

©Stephen Eastwood 2008 www.StephenEastwood.com www.StephenEastwood.com/bio www.StephenEastwood.com/tutorials