Lighting 101: Using Gels to Correct Light

(Photo by Strobist reader Siddarth Siva)

Some you may be starting to realize already, but I'll say it aloud:

When lighting a photo it is not about absolute light levels. It's about relative levels. You can adjust for just about any overall light level you have by simply changing the overall exposure on your camera. So that zeroes the "absolutes" out.

It is the relative light levels that define the look of your photos. And for shorthand, we call this a "lighting ratio." I.e., what is the ratio of brightness between the highlights and the shadows?

Guess what? Lighting color sort of works the same way. Only instead of adjusting the exposure, we can instead adjust the camera's white balance to zero out the color of a light source.

For instance, if you were in a fluorescent room, you might balance on the "FL" white balance to make ambient light photos. Since FL lights are in fact green (mostly, but pretty variable these days) your camera would compensate by shifting the color balance about 30CC units of magenta. (That's the complimentary color of green.

So if you used flash in that environment, and was "mixing" the balance with the ambient, your flash would appear … too magenta. Your camera is balanced for FL, and there is a daylight-colored light source. Your flash. So that light would react to the color shift in a not great way.

How do you fix this? You turn the flash's light green, like a fluorescent. And you do it with the special green "gel" (AKA "window green" pictured below:

What about those orange-tented tungsten (AKA, "incadescent") lights? What gel would they get?

Hint: It's the other gel in the photo above…

You get the picture—orange tungsten ambient light, you compensate in the camera by going to tungsten WB. And the camera adds blue to the image. So you need to make your flash orange to match.

And you do that with a tungsten gel, also known as a CTO gel. (Color temperature orange.) They can also go the other direction (physically converting a tungsten source into daylight) by using a CTB (color temperature blue) gel.

Simple to mount, you just tape or velcro them to the flash. Leave a little space to vent the heat from the tube:

Heck there are even commercial versions, complete with commonly used gels.

But, as far as being able to make your light pretty much any color you want? Or multiple lights a mixture of colors? Are you starting to see lighting possibilities yet?

Oh, and Check This Out

It appears as though the photo up top brings our last two topics right into perfect example. It was shot by my friend Sid Siva in Dubai. He balanced his exposure by shooting wide open at a high ISO (to get a good shutter speed) and exposing for the street lights. Which looked extra cool when out of focus.

Then he added a little light into the directors face with a small off-camera flash to bring his face back out of the shadows.

But those lights in the back included tungstens, so he did the white balance swap-and-gel, too. Camera on TUNG WB, CTO gel on the flash. Bingo. Is it starting to make sense yet?

Oh, and to get the cool, limited spot of light on filmmaker Mahmooud Kaabour's face, he used a small snoot to restrict the light.

What's a snoot?

Oh, that's just one of several different types of lighting restrictors, which we'll be talking about next. (See? These cliffhangers are worse than Lost, right?)

Next: Cereal Box Snoots and GoBos


Brand new to Strobist? Start here | Or jump right to Lighting 101
Connect w/Strobist readers via: Words | Photos

Comments are closed. Question? Hit me on Twitter: @Strobist


Blogger METALLILAN said...

Hello! I saw this link and i was wondering, what materials do you use to make those gels?

April 09, 2006 4:48 AM  
Blogger David said...

Sorry, should have put that info in the post. You can get them at any theater supply store. They are made by Roscoe, or some stores might carry Lee.

If you get one of the free sample packs, the samples are big enough to just cover the heads of the kinds of flashes we use. That'll give you all of the exotic colors. Then you might want to buy a shoot of CTO and Window Green, because you will use those a lot and want to make new ones occasionally.


April 09, 2006 10:57 AM  
Anonymous Anonymous said...

Don't forget that users of Nikon SB800s get a set of gels supplied with the flash, in that little plastic thing that is usually left in the pouch.

Use these until they wear out, but don't buy the Nikon replacement set - it's way too costly.

April 12, 2006 12:38 PM  
Anonymous Anonymous said...

Beware of the Nikon tungsten conversion gels. They're not CTO's and are quite strong. Although Nikon offers them as tungsten correction, at the very least, they're something other than a simple 3200k correction.

July 11, 2006 1:57 PM  
Anonymous Richard Houtby said...

What about balancing for sunlight? I have both the CTO and window green (thanks for the recommendation) but tried shooting into the sun last night for some balanced portraits.

I'm using a Canon 30D with a 420EX mounted for fill (no PWs yet).

I noticed the unnatural white fill light when shooting the flash bare so I tried adding the CTO to the flash to balance with the setting sunlight. The skin tones came out way too red.

I ended up attaching the CTO so it only covered about 1/3 of the flash and it seemed to have better balance... but it took a bit of playing to get something that looked natural.

What are your recommendations for balancing light shooting into a balcklit scene (sunset) for portraits?

August 06, 2006 12:46 PM  
Anonymous James Cohen said...

After a little bit of research I've found that you might find the green gel referred to by other companies as CC30 Green, (Rosco) PlusGreen or (Lee) 224 "Lee Plus Green"

CTO (Colour Temperature Orange) is a widely used term across the different companies.

August 13, 2006 7:23 PM  
Anonymous Matt B. said...

Will CTO and Window Green gels work the same way with color negative film? Thanks.

September 15, 2006 2:30 PM  
Anonymous Anonymous said...

Please can you give us the links for B&H shop, corresponding to these filters; they have diffrent grade and I don't know which filter is OK. Thank you!

September 15, 2006 5:59 PM  
Anonymous Anonymous said...

B&H Links:

CTO 3407
Green 3304


September 17, 2006 1:52 AM  
Anonymous Anonymous said...

Here you go:

Rosco Cinegel Green 3304
Rosco Cinegel CTO 3407


September 17, 2006 1:57 AM  
Anonymous Richard Houtby said...

Anybody have any idea about my previous post? Isn't anybody finding that using the CTO for outdoor portraits produces too much colour in the flash?
Are you mounting the gel all the way over the flash or do you adjust how much it covers?

September 18, 2006 12:39 AM  
Anonymous Anonymous said...

You may want to ask in Flickr. Many people have worked their way through this area when it was first published back in April.


September 18, 2006 12:43 AM  
Anonymous Anonymous said...

You can buy CTOs in half and quarter strengths. CTO 1/4 makes natural-looking, warm skin tones when balanced with daylight or warmish ambient. Half might do what you need. Also, for natural outdoor portraits use a large (4' x 6') white foamcore board bouncing sunlight onto the subject's face while the direct sunlight rim lights the head and shoulders and background is semi-shaded. Ratios and color balance are automatic.

October 10, 2006 11:08 AM  
Blogger Neil Cowley said...

Here's a wedding image shot in daylight with gels.
I don't have a problem using gels in daylight. Its a nice effect. I do have a problem with CTO being WAY to red to match tungsten settings on my canon system, and most tungsten burns colder than intended anyway. In my experience that hue shifts it to yellow I use Roscoe Straw 3441 and a couple other variants with more yellow to get the right tone for tunsten matching.

October 24, 2006 11:27 AM  
Anonymous PatMunits said...

Mike L. - a professional wedding photographer from Toronto - noted that CTS gel is a better match as it does not produce magenta casts on Canon EOS. He switched from CTO to CTS. See this ROSCOE page for more info on CTO vs. CTS:

November 08, 2006 4:08 PM  
Anonymous Anonymous said...

Why not just purchase the Rosco sampler swatchbook at a penny for swatchbook. I purchased 5 of these this morning, with shipping, it will run me just under $6.


November 14, 2006 12:18 PM  
Anonymous Anonymous said...

I realize the Strobist is "aimed" at Digital shooters.. However, I still enjoy using film.

I recently had a shoot where I used daylight-balanced film (Fuji Velvia), indoors. My subject was lit by light coming through a window. In the background was ambient light from an incandescent lamp.

I'd like to be able to reproduce this scenario, but using a strobe instead of daylight.

Would I need to apply any color gels to my strobe in order to achieve these results? Or is a flash already a close match to daylight?

January 14, 2007 5:31 PM  
Anonymous Anonymous said...

I realize the Strobist is "aimed" at Digital shooters.. However, I still enjoy using film.

I recently had a shoot where I used daylight-balanced film (Fuji Velvia), indoors. My subject was lit by light coming through a window. In the background was ambient light from an incandescent lamp.

I'd like to be able to reproduce this scenario, but using a strobe instead of daylight.

Would I need to apply any color gels to my strobe in order to achieve these results? Or is a flash already a close match to daylight?

January 14, 2007 5:31 PM  
Anonymous Tom Moore said...

FYI B&H has the swatchbooks back in stock for 1 penny ($0.01).

Tampa Bay Photographer -- Tom Moore Fine Art Photography

February 01, 2007 1:10 PM  
Blogger William said...

I have a couple boxes of old color darkroom filters. These are Cyan Magenta Yellow filters that are 6 inches square... I picked them up at a garage sale for a quarter. I'm wondering if anyone has CTO and Window Green equivalents to these filters. CTO is (guessing) somewhere around 20M and 40Y?? Anyone know the location of this reference material?

February 28, 2007 5:15 PM  
Anonymous Anonymous said...

Hi, everyone.

Okay, I guess I'm missing something here...why not use a small grey card (whibal, or the like) and shoot a test shot for the lighting conditions. Later in Camera Raw/Lightroom, adjust the white balance by selecting the card in the test shot with the eyedropper. Is this approach insufficient? I would think it would cut through the difficulty of dealing with mixed lighting, but maybe I'm off-base here.



April 09, 2007 4:19 AM  
Anonymous Anonymous said...

Pete, the point of the gels is creating a single color of light from multiple types of light sources. If you simply used a gray card, you would only be balancing for a single light source, or a mix of both, giving inaccurate colors.

April 29, 2007 1:45 AM  
Blogger TOF guy said...

In the US, the fastest shutter speed to use under fluorescent light to capture a full light cycle is 1/125 second, and not 1/60s as mentioned in the text.

That's because a period of the power sine is itself divided into two sub-periods which are identical except for the fact that the current changes direction. However the sense of the current does not have an effect of the light emitted by a fluorescent light. In other words, that light has a 120 Hz cycle, and a shutter speed of 1/125 s is close enough from 1/120 s.

Use manual or shutter priority modes if you shoot under fluoresent light at 1/125. This is critical because if you shutter speed changes by as little as 1/3 stop, the impact on the lighting color will be significant. The issue lessens as you capture more cycles in one shot and at 1/30s or slower this becomes an non-issue.

In other countries with power cycling at 50 Hz, the fastest shutter speed is 1/100 s.

I suggest that you modify the text, there is no need to post this comment.

Thierry aka "TOF guy"

May 12, 2007 7:06 PM  
Anonymous Aaronfromqueens said...

Hey Strobist, thank you so much for this site! I've been behind the camera for almost ten years, but the use of strobe has always eluded me. Unfortunately one of the first things I learned from Strobist is that I bought the wrong kind of flash last year. (It can't be dialed down.) Oh well, back to the B&H used dept for a trade in.

ps Do you know Andy Cook?

September 04, 2007 2:55 AM  
Blogger jonathan said...

Free sampler kit from Rosco...

September 15, 2007 12:23 PM  
Anonymous Anonymous said...

I wanted to correct your spelling of the word "fluorescent."

This isn't an attack; I am really enjoying your blog.


October 08, 2007 6:08 PM  
Anonymous Anonymous said...

If you don't want to spend too much for your gels, just go to Staples and buy some colored Poly repport holders. I know lots of thech guys would be ready to hammer me for this idea (it's not the same color tone - way off of being "calibrated" too and not the same material) but hey! you pay $0.65 and it's much better than nothing. And if you're ready to pay a few bucks more, I just bought them on e-bay too: LightingelStore ($3.89 each).

January 11, 2008 3:44 PM  
Blogger tjl said...

Dave Honi has a gel kit that works with his speed strip.

A great collection of Rosco gels, cut to fit 99% of the speedlites out there and the Speedstrip make is super simple to attach them

His web site:

January 16, 2008 5:48 PM  
Anonymous Katinas said...


for anyone interested in gels. Just send an email to lee filters and ask for a free filter sample pack. I orded one some time ago, had it in two or three day's, from the UK to the Netherlands, there are more collors than you will ever use, its just fantastic. Good luck.

February 02, 2008 11:52 AM  
Anonymous John Rohde Jensen said...

After a bit of research I’ve figured out the filter number for those of us who use Lee filters.

The numbers are: 204 Full C.T. Orange (Daylight to Tungsten 3200K) and 244 Lee Plus Green (Green cast to match fluorescent).

March 02, 2008 7:24 AM  
Blogger Jon.B said...

I am working my way through this blog and love it. Thanks!

On the subject of fluorescent lights I notice you don't mention electronic ballasts. These are worth mentioning mainly because of the lack of flicker - the frequency is from about 20 to 50 KHz which is quite a jump from 60 Hz.

Here is something else: what about fluorescent bulbs with a decent CRI? (ie over 80). I can buy GE T8 (standard 4' fixture) SPX50's for $2.6 ea and they have a CRI of 86 at 5000K. Shooting a friend's wedding I actually advised the replacement of the ballasts and bulbs in all the fixtures of the hall. During the process I snapped a few shots showing the contrast between the old and the new - quite remarkable. (The motion got approved on the basis of efficiency - not only are the new bulbs brighter but they'll pay for themselves in about 2 years...)

So... sure you have to be able to deal with old fixtures/bulbs - but it seems like there are (and will be more) many situations when you would automatically be gel-ing your flash green and that would be the wrong thing to do?

Finally, regarding gel-ing your flash to match the green: worse than a color cast is the fact that parts of the color spectrum are plain LEFT OUT by mediocre fluorescents = some colors are unrecoverable (ie, not there in the photo) - unless you make sure your flash gives the lion's share of the light!

I'd like to hear more on this!

March 03, 2008 3:34 AM  
Blogger Giles said...

For anyone who is in the UK, you can give Lee a call and request swatch books, which they will sent to you free, along with an information-packed brochure. See here:

Apparently their US-based site is coming soon, but if you have a look at the holding page, they have posted contact details already:

Hope this helps.

March 27, 2008 6:02 PM  
Blogger Giles said...

Hi David,

Looks like a bit of a folow-up to my last post on this page! Anyway...

I know you are always on the lookout, as we all are, for sources of lighting goodies...

For CTB & CTO filters (as well as others) you might want to check out this page. The price quoted is for a 24"x24" sheet, so imagine how many gels you could get out of it for your SB-800s (the fresnel only measures about 2 1/4"x1 1/4"!

Ok, so they list 'Europe' as the post-to destination, but I don't see why they couldn't help you guys out over there in the States.

For what it's worth, I just ordered some larger kit from these people (I'm in the UK, as you know) and it arrived next day, following a really polite and professional service.

April 04, 2008 3:06 PM  
Blogger Giles said...

A quick update to my last post...

Having been in touch again with that same company, I'm told they have now released dedicated Lee Filter strobist sets which contain 20 filters, designed for use on speedlights etc here

Oh, and they have also confirmed that they are more than happy to dispatch to you guys in the US (as they frequently do).

Again, hope this helps.

April 10, 2008 12:31 PM  
Anonymous Mike C said...

Strangely enough - I have been using different colours of Post-It notes to do this - works great!!!

May 08, 2008 11:00 AM  
Blogger Jason Leane said...

There may be a source for cheap or free gels, provided you only need to gel the flash itself, and can use a small piece. Most theatres have huge bins of scrap gel - gel too small for any of their lights (meaning you can't get a 5.25" square out of it). The staff typically use it to gel their flashlights and such. If you talk nice and/or bring beer, there's a good chance you'll walk away with 20 pounds of gel. Having said that, you'll never find CTO or any other color correction that way.

Also, theatrical lighting companies are probably a far better choice for getting sample books... most around here have a large bin of them by the door, and don't really care what you want them for.

May 15, 2008 3:39 AM  
Anonymous Niall Chapman said...

for uk readers looking for flash gels, i just wanted to share this site i found:

they are obviously fans of strobist - they name-drop it, and they sell flash gels and ball bungees :)

June 28, 2008 10:54 AM  
Blogger mab said...

Thanks Niall,

This is just what I've been looking for.

June 30, 2008 3:06 PM  
Anonymous Bernie(UK) said...

I strongly object to this idea of Bob being my uncle. Bob is my oyster. The world is, in fact, my uncle.

July 08, 2008 11:05 AM  
Anonymous dave wright photography said...


i might suggest that this would be a good place to show that a gray background can be white, black, gray, or any color of the rainbow - if properly gelled.


July 13, 2008 8:03 AM  
Blogger tikal said...

Thought this would be a good picture to show what happens without gels hehe..

July 24, 2008 1:14 AM  
Anonymous Tunnel Rat Studio said...

I'm sorry about this comment being not entirely relevant to the post above, but is there any interest in using gels when shooting black and white? Or a way to mimick the effects of White balance tricks using colored filters? I'm a film shooting photo enthusiast, who could benefit a LOT from your posts, as might others, if you gave just a few little film oriented pointers now and then...
Great blog anyway, thanks for sharing all that knowledge!

October 06, 2008 1:02 PM  
Blogger Dustin said...

what's the consensus on using gaffers tape to seal the edges of the gel (to make sure there's no light bleeding)? I had been planning on doing my setup just as is shown in the photo here with the velcro straps, but saw somewhere recently that someone recommended using gaffers tape to seal up the edges.

October 08, 2008 6:41 PM  
Blogger tgrudzin said...

I cut my gels to size on use transparent tape. You can seal or overlap your edges. I always carry a small roll of 1/2 inch, or you can find on or near a desk or security station. Plus the flash will just push right through it. This allows for a quick adding or subtracting of an Omni-bounce or using the little flip card.

October 12, 2008 3:29 AM  
Blogger .felix said...

Here is my try for a plastic gel holder, bent with a torch lighter (in reality just a lighter :) Click the 4 arrows for a full screen slideshow.

November 23, 2008 3:19 AM  
Anonymous Dane said...

If you are using a diffuser like the stofen, how do the gels work. Or what about shooting through or into an umbrella. Wont this change the color of the light from the gel?

December 31, 2008 3:57 PM  
Anonymous Anonymous said...

This goes to Matt B...
I know that you posted your question a long time ago but... Here is my thought anyway:

Well, the gels will work the same for balancing the light sources if you use film. The difference is that on film cameras you cannot adjust the white balance as you do in digital. You would have to use color balanced film or color correcting filters on your lens. Otherwise, the idea is pretty much the same.

I hope you will read this, but you have that probably figured that out for yourself.

BTW... Thanks for a great blog David!

January 27, 2009 1:28 PM  
Anonymous Anonymous said...

For people in the UK wishing to find Rosco sample books:

February 26, 2009 12:42 PM  
Anonymous JB said...

hi! i've seen a couple of outdoor strobes shot taken during the golden hours and i noticed that the model's skin is in orange tint while some photogs shots are not. are they missing something? is gel a solution in here? thanks!

July 05, 2009 2:06 AM  
Blogger Blaine K said...

I bought some packs for my 3 flashes at Price was right and they fit perfect.

July 07, 2009 11:56 AM  
Anonymous Anonymous said...

I would just like to humbly point out that the ballasts on the newer t8 and t5 flourescent lights are high frequency. The frequency that the phosphorescent particles coating on the tubes are lit at a rate ranging from 3000 to 6000 Hz and, therefore, only the really old ballasts, which are probably not manufactured anymore due to its inefficiency and due to environmental concerns(PCB content), will still be operating on the 60 hz range.
In short, it is nice to know that if one is working under lighting with really really old ballasts, that one can adjust the speed to capture a complete or half a "sine wave" minimally to obtain acceptable results.
Most of the time, if not all the time, one will be working with a modern ballast fired-fixture.

In some instance for modern lighting fixture, a slow standing waves occurs throughout the length of a flourescent lamp. This occurs due to the superposition of the 60hz ac power supply,the ballast operating frequency and other noise frequencies generated by the ballast.

If this happen to you while you are shooting, then all you have to do is turn the lights off and turn it back on after a few seconds. It will usually go away.

July 18, 2009 9:58 AM  
Blogger tom_girling said...

I've written up a simple method for attaching gels (either free samples or bought & cut to size) to your strobe as an alternative to using either tape of can read more about it here.

August 25, 2009 12:43 PM  
Blogger Pretty Ugly said...

noobie question, but do gels work on flashes when you want to reflect light? (..say off a silver umbrella?)


August 27, 2009 2:36 AM  
Blogger Colin said...

I made up a simple little thing with plexiglass to hold a gel. Pictures and a video on flickr of what I did. Had to come up with a name so PlexiGel it is. Less than $10 in supplies would easily make a dozen of them and raw unit cost is about $0.40 and less than an hour of time to make.

September 11, 2009 9:31 PM  
Blogger Simon Peel said...

Just to reiterate other's comments about; I stumbled over the site a few days ago whilst reading Strobist with my credit card out (something I can advise you all not to do!).

Fortunately it saved me from wasting money on stuff from Amazon and other places that probably wouldn't have cut the mustard.

Jason's gels are all cut to size and can be supplied with or without velcro already stuck on. All easy enough to do yourself (and you can even get the velcro from him) but i just wanted to give him some more support here since his prices were great and the service (ordered Sunday night, received Tuesday morning) was fantastic.

So thanks Jason, and thanks to the other people here that mentioned the site.

December 01, 2009 3:08 PM  
Blogger Maiwa Handprints Ltd. said...

Hello David,

I thought Strobist readers might be interested in this case of color balance. Sometime's color balance is creative or optional - but when you are documenting a virtual restoration of a 500 year old tapestry there is at least a little motivation to be careful. We've put up a blog post at:
documenting a very interesting case of color balance with photographs of a virtual restoration of King Henry VIII's tapestries at Hampton Court.
We are mostly concerned with textiles and natural dyes, but as that takes us around the world photographing a lot of things, we are also very interested in photography. We follow Strobist and have learned so much from it. Thanks for all your edifying work.

Tim McLaughlin - Maiwa

March 03, 2010 1:46 PM  
Blogger Wim said...

it got mine through

so far they have been an amazing help,
thanks dave!

September 21, 2010 8:14 AM  
Blogger nadine said...

If you are in South Jersey area, you can pick up samples gels from

Starlite Productions (
9 Whittendale Drive
Moorestown, NJ 08057

You have a choice of LEE Filters, roscolux or GamColor samples. I was able to get one of each. I was going to buy a sheet of CTO and Window Green, but did not know which one to choose. I believe they sell them for about $6.00 or $6.99 per sheet of 12x6.

Starlite Productions is a great place to rent audio, video and lighting equipments.

Which CTO and Window Green should I use? They all have different variations and numbers.

October 15, 2010 2:56 PM  
Blogger Eric Gibaud said...

Just to mention for European users that where you say the 60Hz for Fluorescent lighting, in Europe is 50Hz so you should shot at speed that are multiple of 50. ie: 1/50s, 1/100s, 1/250s etc..

November 23, 2010 7:44 PM  
Blogger Kris said...

Just in response to Pete's comment - yes you can use a grey card in Photoshop to get a good colour balance and it does not matter that the cast is different from different light sources as you can develop different portions of the RAW photo in different ways and mask them together. So being ridiculously pedantic the comment in the blog that that 'even photoshop cant correct for this problem' is not true. Having said that,buying a gel is way quicker and easier than messing around with multiple masked RAW outputs in photoshop.

January 06, 2011 1:44 PM  
Blogger Timothy Lui said...

does the CFL light bulbs that are becoming increasingly popular also cause the color shift when shot at 1/80 (catching the sine wave?) I know they are compact fluorescent but I wasn't sure if it was fluorescent across the board or if different types of fluorescent did not cause color shift. Also I know there are many different specs/ratings/colors of CFL based on manufacturer. Can anybody confirm? or anybody have more details?

March 03, 2011 1:43 PM  
Blogger Howard said...

What about AUTO WB? doesn't that balance the camera to the flash? and therefore cut out the need for a gel? I shot at a wedding with all types of lighting put the camera on auto wb, and everything looked fine.
Don't laugh at me I'm a newbie.

April 24, 2011 3:55 PM  
Blogger DANI said...

Hi, after reading and enjoying this great side for a while, getting inspired and starting to craft and try etc and having just received my set of Lee gels i directly started velcro-doublesided-double-dotting my gels and somehow got to that point to ask myself "how am i going to carry them with me without getting all messed up?" Is there any "smart" way of transport, since i am sure there are a million dumb ways to carry them.. Does anyone have a nice DIY solution? Thanks!!

April 28, 2011 1:45 PM  
Blogger fmueller said...

I love this site - great advice and well written, but please stop talking about florescence (the time or condition of flowering) when you mean fluorescence! :-)

November 16, 2011 12:00 AM  
Blogger Greg Veit said...

I've been using gels in practice for a few years now quite successfully. The only issue is that sometimes it's not clear what colour a light source is because it's not an obvious strip fluorescent or blub-shaped tungsten. Is there a way good way to determine colour temperature if you can't tell by looking at the source?

December 23, 2011 4:43 PM  
Blogger Tonitone said...

I don't get it. It says you put a CTO on your flash if you correct your WB for Tungsten light in the theory section.
But for the example picture it says he uses a CTB on the flash with the White balance corrected for Tungsten. Wouldn't that be going in the wrong direction?
Thanks, I think I may learn something here.

December 21, 2012 7:07 PM  
Blogger David Hobby said...


Nope, YOU were right, and you DO get it. I had recently done a rewrite of this 6-yr-old post in late 2012 and placed a CTB where a CTO should have been.

Nice catch, and thanks!


December 21, 2012 8:45 PM  
Blogger Ryan McNeal said...

Hi. I don't get it where did u speak about lighting ratio? Thank u very much.

May 22, 2013 11:07 AM  
Blogger Ian Mylam said...

Am I right in thinking that this technique of velcroing the gel to the flash head won't work when using the dome diffuser on the flash?

October 16, 2013 6:36 PM  
Blogger David Hobby said...


Actually you are wrong in thinking that! :)

October 16, 2013 11:51 PM  
Blogger Ian Mylam said...

DO NOT PUBLISH (unless you think it would help someone else!)

@Dave: I appreciate you are very busy, and I normally don't ask for spoon-feeding - but am I being really dumb here?

I am using Nikon SB-900 and -700 Speedlights. The Rosco 'Strobist' gels are only slightly longer than the width of the flash head. If I add hook velcro to the ends of the gel, I therefore need to put loop vecro on the flash right up close to the lens of the flash. This then obstructs the slots where the dome diffuser clicks in. I am looking at your 'Lighting 101: Using Gels to Correct Light' post, and the pic showing the gel mounted with velcro to the flash looks like it would definitely foul the dome diffuser, unless I am missing something obvious.

Thanks for any illumination you can offer. If you are too busy to a answer questions like this, then sorry to have bothered you, and of course I understand.

Thanks for a wonderful resource.

October 17, 2013 8:04 PM  
Blogger David Hobby said...


Most people gaffer tape their gels to the flash. Or you can extend the edges with tape sandwiches and apply sticky Velcro. Just throw some common sense at it.

Also, comments on a seven-yr-old post: Not the best place to do a one-to-one advice thread. I would request you use the FLickr Strobist group to have others benefit from the QA. Thx much.

October 18, 2013 1:04 AM  
Blogger Ian Mylam said...

Many thanks David. I'll do that.

October 18, 2013 4:28 AM  

Post a Comment

<< Home