A Visual Science Lab Blog Reader asked, "Why filter your flash?"

 He asked if I was the last photographer to carry around color filter gels....

Here's the answer: We tend to believe that the automatic white balance in our cutting edge cameras will be able to correct for any color inaccuracies in the scenes we encounter when photographing. Many think that this will work by blending or mixing the various color casts together in one file which will somehow be correct; but rarely is.

Here's the prevalent scenario for event shooters: We are in a large room that is lit by tungsten light bulbs. There is a tungsten spot light (or two or three) illuminating a keynote speaker. We need to take images of people talking together at their tables, conversing together at the back of the room and also watching the speaker. In short, we need to handle a range of shooting situations in an environment where the entire room is lit at >3200K while our lighting (and motion freezing) instrument is color balanced for somewhere between 5200 and 5600K. If we use the flash with auto white balance engaged on our camera then whatever is lit by the flash will be close to normal while the some much warmer light contaminates the edges of the subject and the background goes red/orange. It's not a great look.

If we want to have the room show up in the frame (with the subject in the foreground) then we have to find a shutter speed/iris/ISO combination that provides an exposure in which the main subject is lit to a good exposure and the background of the frame is also lit enough to see details and bring up the general exposure of the room. That might be 1/30th of a second, f4.0 at ISO 1250. If we do this then the room light contaminates the main subject to a much greater extent because there is very little difference in the amounts of mixed lighting hitting the subject and the background. 

But, if we put a correction filter in front of the flash which converts the flash color balance from daylight to something much closer to the ambient illumination's color temperature then we're shooting under two light sources that are much closer in character to each other. Since the filter provides a known color temperature we can easily select the lightbulb icon in our white balance menu or we can fine tune with a set Kelvin number to best match the two light sources. 

Now when we shoot a frame of the two guys talking in the back of the room, illuminated by ambient light from overhead and flash from the front the two light sources are close enough to be homogenous and the scene is more natural to our eyes and less contaminated by mixed colors.

I find that exposing this kind of work is best done in the manual exposure setting because one can use the shutter speed setting to increase or decrease the overall illumination of the ambient portion of light without changing the amount of flash on the subject. Through trial and error we can have a background/foreground ratio that is nearly equal or we can dial down the background light so the subject stands out more. We can control flash via the power setting on the flash or by changing the aperture. If we change the aperture to affect the flash we can compensate for the change to the background with our friend, Mr. Shutter Speed. 

Done this way you never have overly warm flesh tones or horribly murky backgrounds. You could, of course, create your own color style by picked a filter and a color temperature setting that is halfway to tungsten and letting the background go warmer or you can filter the lens and leave the filter off the camera to get the same effect as described in our initial example but I can almost guarantee that filtering the lens is going to require a couple of stops more power and exposure and will make autofocusing nearly impossible.

One part of the equation remains; what to do about the speaker on stage? Well, if the stage is well and amply lit you don't need to do much more than identify the color temperature of the fixtures being used to light him or her and then set your camera accordingly. Turn off your flash altogether and snap away. In my example from last Friday it was pretty obvious to me that the fixtures were tungsten balanced and that cued me to set the camera to 3000K (most lighting people use dimmers to pull the lights down a bit so the speaker doesn't get the "deer in the headlights" look) to get a nice, neutral color balance. If I don't  use flash I don't annoy the audience or the speaker, and if I'm using a state of the art mirrorless camera I can shoot in complete silence and pound away at anywhere from 12 to 20 fps to capture the "magic moment ==== I don't though because it's a lot more fun to practice catching the right expression through anticipation and faster reflexes. And it makes it so much easier to wade through the files in post.

Just because you have a flash on your camera doesn't mean you have to use it....

To re-cap: Make all the light sources as close to the same as you can. Filter your flash to match the vast ocean of available light in the ballroom, meeting room, convention or conference center and then set the right white balance for the filter in your camera's WB menu. Use your shutter speed to change the ratio of the ambient light in relation to flash. Use aperture to increase or decrease flash exposure and then restore your ambient/flash balance with the shutter speed.

Shutter speeds too low? Flash not powerful enough? Don't be afraid to increase your ISO.

And that's how I generally handle lighting mismatches and why. Thanks for asking!

Weekend Notes. Galas. Cameras. Clipping Path Hangovers. Counterintuitive Event Cameras, and a bit of Swimming.

This here flash is a Godox TT685O. 

It's a right good unit. 

Sure enough.

It's the weekend. We're in the first week of November and temperatures in the mid-to-high 80's mean we're still fighting swirling flocks of mosquitos. The Texas sized mosquitos; as big as dragonflies. Best bring along some insect repellant with DEET if you're planning to join the nationwide trend of moving to Austin to enjoy the view from the center of the universe, there have been cases of West Nile virus reported in surrounding cities...

Let's talk gala's. Big ass, fundraising galas. One of my clients asked me to come to a gala last night to take photos for three hours. She's been a client at various tech companies for years and years so, of course, I said yes. 

Sadly, I think I've matured away from galas. Or I've been to so many I'm having banquet ennui deja vu. When I got to the massive and imposing downtown hotel and waded through the throng of people at the bars which encircle the actual property, like a tipsy human moat, I headed upstairs to the 4th floor ballroom. The big one. I had on my dark blue suit and a shirt with a tiny black check pattern that I bought on a lark at Nordstroms. When I hit the fourth floor the ballroom foyer was filling up with woman in that odd age group of 30s and 40s who all seemed to be wearing variations of prom dresses ---- or those vengeful bridesmaids dresses that people remember with shame years later.

Most galas have all the standard features of fundraising. There's the "silent auction" with products and services donated by friends, associates and vendors. Mostly vendors and artists. There's the perfunctory 45 minute "happy hour" at the beginning where the women in odd dresses and men in an assortment of crisply tailored suits, or ill-fitting, off the rack suits mill about in little groups with a drink in one hand and a smartphone in the other. 

Uncharacteristically, I had little contact with the person requesting my service. I knew where and when but had no idea of "what." It was an "agenda on the run..."

My first duty/position was near the entry area where the client had set up a background with a logo in the middle of it. I guess no one really thought it through but really? The big logo right in the middle? Five feet wide? On an eight foot wide background? We might be able to break up a couple and put one person on either side of the logo for a photograph but I think that would be very awkward. The problem was more or less immediately solved when people started coming over to be photographed in groups of four, six, eight; even twelve. The logo stayed behind them. We couldn't figure what else to do...

But let's talk about a new understanding of "event photography" for a minute. In the past people would dress up (gentlemen, at least buy a shirt on which you can button the top button and wear your necktie correctly....) and part of the gala process would be for each couple to have a commemorative photograph made. Now it seems that the "step-and-repeat" background serves two masters. The traditional photography paradigm and then (a bigger priority) the iPhone selfie hordes. 

I stood at the ready with my camera and a flash but the majority of the attendees were happy to group themselves into small clusters on the background, do the little bended knee posture and then make "duck face" for their own cameras, which were being wielded by their friends. At one point a number of small groups of prom dress women did ask me to make their group photos but most only wanted me to do so with their phones. This year, and perhaps the next few, will be remembered by photo historians as the period of time in which every young woman was photographed with a phone in one hand and a drink in the other. But no photos will actually exist since our government (or what's left of it) will outlaw Facebook, Twitter and Instagram in an attempt to limit election fraud and, as the services go bankrupt the first things to go will be people's photo albums....No one ever said social media was benevolent...

Moving on, the guests are summoned to dinner by hotel food and beverage people who walk through the happy hour space in the foyer striking little melodic chimes on tiny, handheld xylophones. The seating process is arduous because the entry into an new room reminds everyone of something they forgot to mention to their friends during the happy hour and fifteen minutes later people are still standing next to their tables yakking as the emcee for the event heads to the podium. 

Our emcee is a real celebrity. He's the local weather man on one of the network channels. He's been calling out the weather (or flipping a coin and faking it) for decades here in Austin and, of course, his first comment of the evening is about the weather. Ouch. 

Dinner gets served as people speak about the merits of the charity being bolstered. Cute kids are sent to the microphone to testify about how much their lives have changed since joining this program. 

Now the guests have had drinks at happy hour and decent wine at dinner. They've been softened up by videos and testimonials from all the people the charity has helped and now the big guns come out; the auction, with a crew of five auctioneers all sporting gray cowboy hats. The things being auctioned off are more or less events or experiences. You can bid on a trip to taste vintage retsina wine on a Greek Island for you and your closest seven friends. Go hunting for Pandas at the world's greatest hunting lodge is some vague area of China (kidding). And, the recurring auction item of the decade (as witnessed at five different galas...) VIP tickets for six to see "Hamilton." 

This gala was bigger than most in Austin and easily raised over a million dollars. It was so big that the organizers had cascading shifts of photographers. Mercifully, I was slotted from 6 to 9 pm. I was out the door with my take at 9:05...

But let's talk about the gear. Since I was working strictly in the role of publicist/documentarian I packed lighter than I ever have before in my career. The choice of camera was made for me by my recently reduced inventory of cameras. It was either going to be a Panasonic GH5 or a Panasonic GH5. The lens was even more of a "no brainer." What better lens could I want than the Olympus 12-100mm Pro? A nice, wide angle for those big groups festooned across the logo'd backdrop and a tight, 200mm equivalent for shots of the keynote speaker up on the stage. All bundled with exceptional image stabilization. In fact, the stabilization is so good that, at times, I can take both hands off the camera and it floats in place, in midair, on its own! (hyperbole alert. do not try this with your camera....).

The only real question I had was "which flash to take?"  I have a shipping crate full of manual flashes from Godox, Cactus and Yongnuo but I decided I would like a dedicated TTL flash for the Panasonic system. I've had good luck with Godox lately so I splashed out $125 on the model, TT685O, which is the same form factor as several others I own and useable with the same remote triggers. It features full automation and can also be used as a master or slave flash in a multi-flash system.

With Eneloop NiMH batteries the flash worked like a charm.  My first use of the flash was in taking shots of couples in front of the above mentioned logo'd background. I tried a bunch of flash modifiers but shooting directly into a shiny vinyl background was always going to create a hot spot so I defaulted to bouncing the flash off the high, white ceiling. It looked much better. I started with the system on TTL but sometimes large expansive of white prom dress caused underexposure while couples draped entirely in black caused some overexposure. I realized that I could just set the flash to manual power at about 1/2 and, since our positions rarely changed, the exposure on my subjects would be absolutely perfect from shot to shot.

I started off shooting in AWB hoping to mix the ambient lighting with the flash but didn't like the way the flesh tones inevitable went to warm. I put a full orange filter on the flash to match it to the basic ambient light color and then set the camera at tungsten. Again, bypassing the automatic setting made for very repeatable results and much more pleasing color on the faces of my subjects.

Let's talk about that lens for a second. You know how everyone talks about how you can tell a great camera sensor because you can shoot it at the base ISO or ISO 1600 and by lifting the base ISO exposure to match the 1600 ISO exposure there's no difference in noise? I can't remember what the wags at DPReview call this but I'm renaming it "sensor indifference." What it basically means is that up to a certain level it really doesn't matter where you have the ISO set, the files will look the same.

So what does this have to do with the Olympus Pro lenses? Well, I very much believe that they are truly aperture indifferent. They look as sharp and contrasty wide open as they do stopped down to f8.0. I used my 12-100mm at f4.0 all evening and when I got back to the studio and magnified the files to 100% I was re-surprised at how sharp and detail rich the files were. Even at ISO 800. It's exciting not to worry to much about focus. The contrast detect AF is nuts on accurate and even though the focusing speed slows down in dim light (hello grand ballroom) when the AF confirmation signal locks you know you've got it nailed down.  It's fun to shoot with an aperture indifferent set of lenses because you never have to worry about trading lighting gathering for sharpness.

The camera (GH5) was a counter-intuitive choice for event work mostly because nobody seems to work with it that way. In our rush to mark this tool as a video centric imaging solution most reviewers have overlooked its very competitive still photography performance. The files, when created with discipline, are absolutely beautiful. The flesh tones make me happier than what I've been getting from most other systems and the size of the package for the performance is ridiculously good. I finished out my three hour shift with nearly 700 images on the V60 SD card (no wait for a buffer, ever) and I still had two of the three bars on the camera's battery indicator. Very pleasant, no struggles.

I think I've found one of the sweet spots between the one inch sensor cameras and the full framers.

Clipping path hangover.... What an ordeal. For a number of days last week I'd wake up at six in the morning fretting about getting all the clipping paths for 91 files knocked out in time. Each file needed to have two different clipping paths and we needed to work at a level of precision that would allow the images to be used in just about any medium. I'd lumber into the kitchen and make coffee and then, cup in hand, I'd head out the front door of the house and into the studio.

I had operational amnesia about one aspect of path making that I could not solve but was so happy to have the braintrust at our VSL blog rush into action and save me from my own ignorance. Another big "THANK YOU!!!!" to a brilliant advertising agency owner in Toronto, Canada for getting me the information I needed just when I needed it.

I preach against sitting in front of a computer screen doing fine work all the time but it's exactly what Belinda and I did last week. I've spent the better part of the weekend walking around in a daze, staring off into the middle and far distances and occasionally trying to extend my vision to infinity. And this just a week after getting new eyeglasses....

Every time I finish a project like this I say, "Never Again." But a few months later, when accounts receivable dip like a well drying up, I succumb to the weakness of commerce and, smiling, agree to another bout. When will I learn?

And now for the real reason most read the blog: swimming news!!!!

As you may recall, the water at our newest swim destination, Deep Eddy Pool, took a decided turn toward frigid last weekend. Apparently the city was using water from a back-up well while they fixed the pumps to the main well. The pool is refilled every other day so when they switched from the primary well to the secondary well the temperature dropped from a barely acceptable 72-73 degrees right down to 67 degrees. After a mile swim in that water, last Saturday, I rushed to buy a short wetsuit to preserve core temperatures for future swims. It came in very handy on Sunday when the water was also like the Antarctic ocean.

But this last week the repairs to the pumps were made and the pool has cleaner and more temperate water than I've seen since I started swimming here again a month ago. the temperature is back into the 72-73 zone and the wetsuit stayed in the car all week long. I have been warned, however, that the well water temperature will start dropping as soon as (if ever) we get some winter weather. I'm keeping the wetsuit handy....

Yesterday I met up with my friends, Anand, Emmett and Julie  and we self-coached a 3200 yard workout, from noon to one pm. We did 33.3 yard sprint sets, sets of 66.6 yards, sets of 100 yards and we interspersed these with 200 yard kicks and 400 yard distance swims. Swimming in colder water than I have been used to for the past 20 years is different. Muscles get tighter which causes more resistance. But the water seems to keep core temperatures in a good range for best recovery/performance. We're swimming harder and better but man! am I tired and sore later in the day.

Thinking about getting an inexpensive underwater camera to shoot some video with, if anyone has any suggestions.

Coming up. I deliver the clipping path job tomorrow afternoon and then, for the rest of the week I'll be on pins and needles waiting to see what new camera Panasonic will be releasing. There are plenty of rumors and a rumored date of Nov. 6 for the announcement. If it's a cool still camera and less pricy than the GH5 I'm pretty much in.

Also awaiting the release of the Olympus 45mm f1.2 Pro lens. I'm arranging to borrow one from my local vendor to test and see if it's really so much better than the Panasonic 42.5 I currently use. If it is then it may be irresistible.... I'm finding it increasingly difficult not to be assimilated by the Olympus Pro series lenses. So far, they are a brilliant differentiator between existing formats.

The clipping paths have been completed. The sample sent to the client was approved with high marks. Ahhhhhhh. Now to relax at a gala!

Belinda and I methodically made our way through the 91 compound clipping paths. Now our client will be able to use the file with a white background and their product on a white (shiny) mannequin. They can select the next layer up and have an image of the white mannequin+their product on a transparent background, with an embedded clipping path, or they can go to the next layer up and have an image of their product sitting on a transparent background with no mannequin ---- but with a very nice, attendant clipping path.

It takes more time when the mannequin needs a few little scuff marks retouched, etc.

I made good use of the curvature pen tool and also the "select and refine" option.

I finished the project in enough time to have a late lunch, to pack and to head downtown for a gala at the JW Marriott Hotel for the Boys and Girls Clubs of Austin.

The glamorous life of a photographer....

Tonight I'm packing a dedicated (TTL) Godox flash for Panasonic/Olympus, a GH5 with the 12-100mm lens and a bunch of batteries. Too set in my ways not to bring along a back-up rig so I've also packed a G85, the small and lightweight 12-60mm lens and an extra manual flash. And again, batteries for all.

At least business is brisk.

VSL Reader Help Requested. Clipping paths get more complicated in latest PhotoShop.

This is a measured plea for help. By measured I mean that I am not yet panicky but a bit frustrated. Maybe you can help with a clearer workflow for me.

Stuff I think I know:

There is no substitute for hand drawn paths with bezier curves for documents that will go to print.

There is no way to automate complex selections.

White on white is its own problem.

I know how to use the pen tool and how to create a path. In previous versions of PhotoShop, if you needed compound clipping paths (paths within a path or multiple paths in a file) you could draw one path hit the shift key and begin another path. And another. And another. Then you could click on each path and they would all work in concert to create a clipping path.

Not so anymore. Now I can create a new selection, see it in the work path icon (in the paths palette) but when I go to select the multiple paths I only get the first path or a subsequent path as my selection and not the multiple paths.

A good example would be a product with many holes through which you can see the background. In preparing for printer files each hole would have to be part of the overall clipping path. The primary clipping path would be the whole product (to clip it from the background) but I would need to create smaller clipped areas for each of the holes as part of the working path.

This is where I am stumbling. Not every file has these needs but enough of them do to make me grit my teeth.

My partner is working on an older version of PS and has no issue whatsoever producing as many smaller clipped areas inside the overall clipping path. None at all.

If you understand the clipping path workflow in PS CC 2017 I'd love to have the largess of your greater skill and brainpower.

Help?

P.S. I've searched for tutorials for hours. I can composite a fashion model on a background now but only if the composite doesn't require me to make paths inside of paths..... grrrrrrr. KT

Help us all understand this admittedly specialized part of the new PhotoShop!

Back into the weeds of commerce. Clipping path saturation!

I've written enough about cameras this week. You would think I'm a review site! So I'll write instead about what I'm working on right now in the glamorous and scintillating world of commercial photography. You'll no doubt be so jealous that you'll walk away from your job as chief off shore banking expert at Goldman Sachs to toss your hat in the golden ring of product photography. One day, you to might know the pleasure and satisfaction of ..... the nuts and bolts of photography.

Last Thurs. and Fri. I set up the studio and completed the principal photography for an international client whose H.Q. is located in Germany. Their north American headquarters is here in Austin. I was tasked with photographing 24 medical products displayed on a (shiny) white mannequin (top half of thebody...) against a white background.

We had a product manager, an project manager, a technical specialist to make sure the products were correctly fitted to the mannequin, as well as a person who was there to learn how these kinds of shoots are done so she can supervise her own projects in a different, but related, department. I made coffee and Belinda baked a loaf of pumpkin bread the night before. We also had fresh bagels and creme cheese as assorted fruit. We want to keep our clients well fed.

The products were things like body braces and immobilizing medical devices that might be used for patient who had been subject to trauma or were in recovery from spinal surgeries and neck surgeries. The products were mostly black with some plastic trim pieces in white or mid-gray.

We set up a shooting table in front of a white background and covered the table with shiny white dry erase board material. Since we would need multiple angles of the mannequin+each device I put the mannequin on top of a very basic turntable after covering the turntable with bright white paper.

Exact exposure for this shoot was important because we needed to clearly separate the shiny white mannequin from the pure white background. Important because at some point some poor bastard would need to create two clipping paths per file....with over 90 files.

I used a light meter to carefully meter the background and then the plane of the subject. This is, for me, a tough metering situation since the white in the background had to go texture-less while the mannequin would have to read at about 90% even when printed on so-so four color press paper stock. But I would also have to preserve good, ample detail in the blacks!

We worked our way through all the products and kept notes that will tie each product to a set of filenames/numbers. At each step we got the client's approval and, at the end I had that exhilarating feeling that we'd gotten through the project without a single hiccup. The files were shot simultaneously on two SD cards (because I presumed I had jinxed myself earlier by ragging on the idea of duplicate card slots and redundant back-ups) and immediately ingested into Lightroom with folders created across two hard drives. All that remained for my part of the project would be to go through and clean up the files a bit, make sure they all matched for color (never varied) and tonality, and to quality check them for focus.

Then I asked the project manager how the in-house designer would like the files delivered. What format would she need in order to facilitate the creation of clipping paths? Big Tiffs? .PSDs? Should I deliver them on memory sticks? Add them to a small hard drive that we use to shuttle big files? Upload them to an FTP address? They had always done the clipping paths in the past.

Maybe the designer was overloaded or overbooked. I might never know... but the project manager asked me if I could do the clipping paths. Being customer service oriented (meaning I want my clients to be happy so they'll: A. Pay me. and, B. Use me again), I said "Sure."

Then he gave me the details. We would need one masked layer with just the mannequin with product on a transparent background. We would need a second layer with just the product (no mannequin), complete with a clipping path for the product. In this way the client could easily drop the mannequin+product into a catalog or just grab the clipped product layer alone and pull that into some other use.

What that means to me is very precise selection (via pen tool) for the overall separation from the background. This selection would go through the refined edge process in PhotoShop and I would select "selection with layer mask" in the "select and mask" menu. Then I would duplicate that layer and, again using the selection tool, I would create a clipping path in the top layer around the solo product. I would then select and inverse the path to drop out the rest of the background (including the mannequin) from just this layer. Finally, I would save the entire file in layers and deliver it as (client preference?) a layered Tiff or .PSD file. Uncompressed the Tiff files done in this fashion; with layers, weigh in at 126 megabytes per. That will give me about 11.5 gigabytes of deliverables.

I did a sample file today and sent it along to the client to get confirmation that we are on the "same page" and that this is indeed their preferred methodology. It takes about 20 to 30 minutes to do each file which means we have about three ten hour days of time in front of the computer to celebrate!!! Of course it's all billable time but it's hardly as captivating as sitting around on Maui with a bunch of bikini models, sipping Cuba Librés and waiting for the light to get neat...

If you wonder why I fantasize about cameras and lenses too often it's probably a direct result of enforced captivity...and a convenient conduit to the internet.

Before all you smart guys rush to tell me all about some clipping services in India that will do this stuff for a song please let me interject that I've been down that road a couple of times and each time I rushed to re-do the work before delivering it to my clients. There is a difference between a ho-hum factory clipping path and careful precision. If you have the right clients then the clients will know. Because, you know, the client's art directors and designers know just as much about good clipping paths as we do....

My workaround is to split the job with my art director/designer wife/partner and share the excitement!!!
Of course, she'll charge me her regular rate but I know her paths will be immaculate and unimpeachable. And that's about all you can ask for in 2017.

Excited? Wanna join in the fun? If you just adore doing clipping paths and need a nice hobby I can send you a folder full of files just waiting to be clipped. And if you own an ad agency in Toronto and can think of a better method than the one I outlined I can send you the files instead... :-)

And that's what we're doing here in the world headquarters for the rest of the week. Enjoying the amazing benefits of the freelance lifestyle --- tied to my desk chair.