Reddit reviews Rosco The Strobist Collection, Strobist 55 Piece Cinegel Filter Kit, 1.5x3.25" to fit most Shoe Mount Strobes.

sure no problem! I bought these recently from amazon. They just go over the off camera flash, I have this one which has a small diffuser that folds down over the front which I slide the gel under.

Here's a pic where you can see the flash with the gel in the background.

EDIT: Fixed a link

One of the cool things about lighting is that you can create light with a variety of different things, so you can really play to your budget really well. As others have recommended, if she's serious about learning to light, tell her to check out Strobist, read his tutorials, buy his DVDs, the like. She'll learn a ton and David Hobby is a great writer. His blog is awesome, too.

As for a basic setup, she'll need some sort of light source, a diffuser (or light modifier or some sort), and some way of triggering that light if it's a strobe. That's the very basic setup. Fortunately for her, she can do this for $10, $20, $50, $100, or $1000. Whatever she (you) are willing to spend on it.

If she's trying to do it on the cheap, she can grab a lamp from Ikea (match the type of the bulb with the type of lighting the food will be in. If she's in a kitchen with flurorescent lighting, get a fluroescent lamp), a work light in a clamp, etc, some paper (try tracing paper or wax paper as it's more translucent), and some tape. Stretch the paper out so that it covers a nice area, tape it up to some boxes or something so it stands, and shine the light through it so it's nice and evenly lit. The only thing that affects the "softness" of light is the size of the light source, so the paper is useful for spreading out the focus of the bulb in your lamp and giving you a nice big source. Be creative, move the lamps around, try layering on the paper or removing the paper. Just play with it and see what works. She'll probably need a tripod and a slower shutter speed though, since these lights aren't incredibly bright. Here's another idea using the same equipment for inspiration.

Moving up in the budget, she can start to explore the world of flash photography, and start playing with strobes. These cheap YongNuo Flashes (and there are other models that are great, too) are surprisingly good, reliable, and cheap! I own a few and use them all the time. They come with stands, but she could tape them up around for better angles. Just one of these off camera, or angled properly can make her photoghraphy stunning. Start by placing them off to the side, aimed at the food, and triggering them with the on-camera flash and the strobes set to "optical slave" mode. Tell her to turn down the on-camera flash power to very low as to not give the food a bland look, and just use it to trigger the off-camera flash. Exposure here gets a little more tricky, without going on a huge rant (I could if you want, just let me know), but she should be able to figure it out. Start on low power, and dial it in more and more until she gets the look she's going for. Then, start experimenting and playing more! Use that same paper as before for a quick and dirty diffuser, or, if you want even bigger, softer, light for free, crank the power and shoot it onto the ceiling. The reflection will give her a great, even light source that compliments nearly everything nicely. Play with the built-in diffuser too, bouncing off different things, etc. Shoot, see what works, have fun, and learn. There's a lot to learn, and she'll learn best by just throwing things at the wall and seeing what sticks. Just make sure she's having fun and not stressing too much! If she needs more help, just throw me a question, google around, or post to this forum. Someone will be able to help.

From there, she can keep expanding upwards. More flashes, umbrellas, light stands (make sure she has all the necessary hot-shoe adapters, or umbrella mounts she might need), snoots, grid spots, and other sort of modifiers she might want to get the look she's going for. Worth noting that most things here can be made with some creativity and some crafty DIY work.

Oh, I'd also urge she get a set (or two) of gels for her lights, mainly the CTO (colour temperature orange) and CTG (colour temperature blue) so she can match the colour of her lights to whatever the ambient light is.

Hopefully this helps. If you have any questions or need more help, just let me know. :)

I used these for weddings with my flashes. They work awesome, and they include a Kelvin rating and how much it adjust it. 5000-5500 Kelvin is daylight (my Nikon likes 4800). 3200-3400 K is Tungsten, Florescent is 3000k with Green.

The florescent ones that come in the pack might need to be doubled up, you will probably lose half a stop exposure (1/3 roughly per green gel). The darker the gel will reduce flash output. This is added on the loss of exposure from your umbrellas/softbox if you use it.

If you use ACR (Adobe Camera Raw) then use the Hue tab for yellows slider in the HSL (Hue, Saturation, Luminance) area to bring it to taste.

If your looking for actual full front to back color management, shoot raw. Photograph this chart with even cross lighting or in daylight with minimal shadows cast on the color patches. Then run this program and it will give you presets for the camera calibration tab in ACR. Same presents can be used for Lightroom since they are using the adobe color engine etc.

To successfully manage this i would stop by to photograph the office quickly to get the color temp correction. Test your flash with a couple combos etc. Your missing one huge component possibly. The light coming into the office, since it is shade, you are going to get about 5800-6000k coming in (shade/direct lighting mixture) which is a blue tone. So you will have corrected for the nasty fluorescent, but now since you dropped to 3000k there is a huge blue source of light coming in.

Either balance everything and deal with the blue in post, or blast everything with un-adjusted flash (or a CTB 1/4) so the florescent doesn't have time to show up. If it is a really cloudy day your going to get a 6,600k which will be bluer than originally planned for, and if that happens you will need probably a CTB 1/2 or CTB full (or 1/2 and 1/4 combined) to balance the lights- also you need to add exposure if that is the case.

By the way it also depends on the type of florescent lights. If it is the new CFL (compact florescent lights) that you screw in, you will not have a problem because they refresh up to 10,000-40,000 times a second. The question is if they are the long tube florescent lights they refresh around 100-120 times a second. What this means is that your shutter speed should be slower than 1/125 of a second because it might catch one not refreshed and then you get to spend time in photoshop. Also the length of exposure balanced with the outside will determine how much of a shift of green you get. Do be aware that the florescent lights that say 'cool white' have a coating that is pretty much doing what the filter gels are doing.

TL;DR Damned if you do, damned if you don't. And your client probably might not care about all this trouble. Great system when streamlined though :)

source: Too many weddings.

I prefer this calibration script, but more advanced. Either script will do the job with minimal differences.

edit: move brain dropping to the correct train of thought.

Thanks for the link. I will check them out.

I have these filters that I plan on putting in front of the light to change to tone/color of light.

Two of them:
First has one has multiple copies of commonly used ones (reddish, cyan, straw, CTO, CTB, etc) and they're a hair bigger (sized for speedlights)
http://www.amazon.com/Rosco-Strobist-Collection-1-5x3-25-Strobes/dp/B002SWIOOM/

This one is the original with one of everything they make (it was the original hack recommended on strobist).
http://www.amazon.com/Rosco-Lux-Small-Swatchbook/dp/B0002ER2YG/

I got some stick on velcro and use those to attach them to my speedlights.

As most people here have mentioned, paper is going to be the easiest to deal with for solid colors. The best thing about paper is that if you scuff, crinkle, or tear it, you just cut off that section and unroll it some more. It's cheap enough to not worry about, and super-easy to work with. No cleaning (like vinyl), and no worrying about permanent footprints. A 36-foot roll of paper in most colors will run you about $40 for 53" or $60 for 107" width. You mentioned groups, so I'd recommend a 107" roll to avoid running out of room. 53" is really just for individuals, groups, and pets or products. Here are a few other things to consider:

Are you always shooting at home, or does your backdrop need to be mobile?

I have two sets of triple-rollers set up in my studio. They can be found for around $70 on Amazon, and can be wall-mounted or ceiling-mounted. Each set lets me mount 3 different rolls, and I have one set for 53" rolls and one for 107" rolls. If I want to switch colors, I just pull on the chain to raise one and lower another. To swap out a color, it only takes a couple of minutes.

For mobile situations, get yourself a backdrop crossbar and a pair of light stands. If you only use them once in a while, you can again find them on Amazon for around $40. But if you plan to use them consistently, I'd recommend getting something sturdier. Westcott makes a really nice 13-foot stand for around $80 each (you'll need two), and their crossbar is around $90, though some cheaper crossbars can be found for roughly half that. You can spend less on a smaller stand, but I wouldn't recommend it; anything smaller or cheaper loses a lot of stability. These stands will last you forever, are still cheap enough to not worry about it too much, and are fully usable as actual light stands in case you decide to start working with off-camera lighting later.

Safety

I'd also recommend 2-3 sandbags for each stand to reduce the risk of someone kicking them over. We live in a litigious country; don't get sued. You can buy empty sandbags pretty cheap (about $20 for 4 on Amazon) and then fill them with $5, 50-lb bags of playground sand from your local hardware store.

How are you using your backdrop?

For either of these scenarios, you'll need some way to keep the background down, as it tends to curl. Your local hardware store carries simple spring clamps for about a buck apiece, and 3-4 of those at each corner and in the middle will keep things stable. I'd recommend picking up a few extras as they're crazy-cheap, and great for keeping your backdrop from unrolling if you aren't using a roller system with resistance.

If you're looking for something seamless, you should also consider a roll of gaffers tape (or blue painter's tape, if you're trying to save money) to keep your paper on the floor, in case you want to create a sweep. In case you aren't familiar with this term, a sweep is where the background makes a rounded, 90-degree turn at the floor, resulting in a seamless background with no "corner". It's how you get those images where your subject is isolated against a background.

What it'll cost you, total

All-told, your total cost for this setup (doing it "right") is going to run you about $300 for your supports (including clamps, tape, sandbags, etc.), or about $100 if you go with the wall/ceiling mount. Paper rolls aren't included in this. This is about as cheap as it gets to do it "right", unless you're looking at an entirely DIY solution... at which point the price can drop to 1/10th of that.

Alternatives to paper rolls

If you're looking for more interesting backgrounds, you have three main options:

• dyed muslins
  
• printed/painted muslins or vinyl
  
• gelled lighting on white paper with a spare flash
  
  Dyed muslins will start at about $40-60 and look like these. Printed or painted ones (muslin fabric or vinyl start at $60-100 and go up from there. But if you have a spare flash, you can pick up the Rosco Strobist Collection of gels on Amazon for between $10 and $20, and then have any color background you want, with a nice, smooth gradient. You can toss it on a backward-pointing light stand behind your subjects, or backlight the backdrop from behind. Note that your camera and flash will need to support wireless triggering to do this, or you'll need some radio triggers.
  
  What you get out of your setup depends on what you put into it
  
  You can do some really interesting things with just a simple white backdrop. The biggest factor is going to be how much time you put into learning how to use it. Here's a post to get you started. Note that this article also has a link at the end to a second article about how to create interesting backgrounds using random objects in front of the flash. Definitely a good read.
  
  Good luck! :-)

haha, i used gels for the first time at a wedding only a few weeks ago. i used some Rosco The Strobist gels on my OCFs just because the lights were so obtrusively warm.

Honestly, just get the gel inserts. The flip systems seem nice, but I'm not willing to pay $50+ when I can get the gel for $8 (and even that's paying too much).
these go for $12, so even paying $8 for a few small circles of the material seems like too much, but that's a niche market for ya.