Wireless P-TTL Flash and the Portrait Studio
Does wireless P-TTL fit a complex environment?
By Mister Guy in Columns on Sep 7, 2015
Forum member Nigel McGregor recently wrote an excellent guide that made me start thinking about my flashes. I've upgraded from shop lights to a set of Pentax branded flashes, and I decided it was time to question assumptions I've made over the years. Do softboxes and P-TTL mix? If I left it up to my camera's computer, what would my normal lighting setups look like, anyway? In other words, how good of a starting point can automagic give me, in my studio portrait setting?
Over the years I have had various mixes and matches of equipment, and only recently acquired a set of flashes that all supported P-TTL. P-TTL is Pentax's version of the Through The Lens metering system. The P is for the metered Pre-flash that is unique to Pentax's implementation. In theory, having compatible flashes meant I didn't need cables or radio triggers, and shouldn't need to adjust the flash strength when moving lighting equipment around to maintain even exposure, at least with A lenses. I would still need to set relative power for each flash individually. Nikon's system is more complex, allowing more refined configuration from the camera. Canon's is somewhere in the middle. When you research P-TTL online, you can quickly get the impression it just doesn't work at all, but most of the discussions are pretty old. I realized to my shame I hadn't even tried playing with a potentially valuable feature, simply due to complaints on the internet from other people.
I turned to social media and quickly had a volunteer that couldn't be better for my experiment. A favorite complaint of the P-TTL system was that it under exposes. My volunteer was Jasmine Brown, a beautiful and patient lady with an extremely mixed ethnic background, brown skin, and even darker hair.
I should probably mention that I stuck her in front of a black background paper, in a room lit by two 65W CFL Daylight Balanced bulbs. I wanted to see if wireless P-TTL and multiple flashes in light modifiers could work as intended, and both expose correctly AND understand what I was trying to accomplish. This is not meant to be a wildly extensive test. I just wanted to see how different my photography experience would be if I used the tools the way they were designed to be used, according to the manuals. I didn't want to need to worry about what direction the softbox was facing, whether the flashes communicated, or really, anything other than making my model feel comfortable, and confident that we were getting good stuff.
About the author
Speaking of my experience, as we all know, one of the most valuable tools we use in photography is perspective. If I want you to care at all about what I say, you'll need to know what my perspective is. I don't claim to be the most successful, most impressive, or most talented professional in the world, and I'm barely making enough currently to justify advertising my services. I was a technical nerd growing up, and only recently tried turning a hobby into a career. Being a professional photographer is about more than creating the absolute most spectacular art in every shot. It's about working hard and connecting with people, and I can control how hard I work, and the choices I make as a business owner.
In my perspective, that means I'm like a lot of people out there who can't afford to upgrade unless they are absolutely sure they know why. Purchases need to be result driven, and I will do everything in my power to use something I have, something I can borrow, or something I can make to do the job. I need to work harder, and I always want tools that can help me out.
Manual K-mount primes
When I bought a digital camera, I bought a Pentax because I read online, and discovered much to my delight, my Pentax digital camera behaved like the film camera I had learned on in high school and taken to college with me. I also bought a Pentax to keep using the smc-M 50mm f/1.7 that I grew up loving. In other words, I bought a Pentax because I was shamelessly biased towards the brand. Much later, right when I was strongly considering trying to sell all my gear and switch to another brand in order to try and get hired more easily as a second shooter, the Pentax K-3 came out and made my decision complicated again. As a photographer, I want the best equipment I can afford, always, and I want help covering my flaws. As a businessman, I want to avoid spending money whenever possible. I want my tools to last as long as possible, and I can't let not having the right tools hold me back.
So that's me in a nutshell. I'm torn between brand loyalty to the tools I'm comfortable with and pressure to switch for either form factor or simply interchangeability reasons. I can't afford to buy anything I can't absolutely justify, and yet, I want everything and try to justify the flimsiest excuses to buy new toys. If any of those perspectives sound even a little familar, consider reading on.
Umbrella style softbox on stand
My equipment list has grown over time as my needs, ability, and budget have grown. I started with your standard big box store clamp lights and CFL bulbs. To even the light out, I started using shoplights behind greenhouse plastic rectangles. I reached the point where I needed to decide between investing in powerful studio level strobes like the recently discussed Priolite or going the strobist speedlight route. For me, smaller hotshoe mounted flash units were the obvious budget and flexibility choice. That didn't mean I didn't want all the features and abilities of expensive studio set ups. I invested in cables, and then flash triggers. I went through a few inexpensive flashes, and decided to invest in the Pentax flagship unit, the 540 FGZ II, and backed it up with a pair of 360 FGZ units.
Despite the doom and gloom about the photography market, the market has swelled with possibilities for all budget ranges. Once you have invested in a flash, you can purchase a ton of powerful light modification possibilities with a kit right around the $150 mark. There are also less expensive brands with lower price points and less features than the Wescott Apollo line.
It occured to me that I was so used to needing to do everything manually, I had absolutely no idea how good of a job the system could do automagically. I was comfortable with manual settings and flash triggers, and even after reading the flash guide and searching for articles online, I didn't know if wireless P-TTL would even work stuffed in a softbox pointed away from the camera. Let alone stuffed inside this thing:
The writing on the bag says, "Please Recycle"
Simple Man, Simple Test
For those of you expecting rigorous methodology and carefully calculated numbers at this point, you may not have been reading carefully enough. My entire goal for this test was to simply put my flashes into the softboxes, put the boxes where I'd normally put them, and fire away. In order to work the way I want, the wireless P-TTL system needs to see the pre-flash in all the slave flashes, measure the exposure correctly, and then all fire for the correct exposure. You can set each individual exposure compensation on each slave flash, and in theory, they should all just figure out what you're telling them and give you the exposure you're looking for. My goal was to see how well I could set it and forget it. Afterwards, I imported them into the Adobe suite, and made the normal type of adjustments and edits I'd normally make.
Headshot Lighting, "Clamshell" and Hairlight
It was apparent pretty quickly the real news was going to be there might be no news, and for me that's a great thing. I was looking for less fiddling, and less interaction with the flash, and more time to play, and that's what I was given. From the very beginning, the system shrugged off any ill effects from direction or diffusers. Keep in mind I'm working in a relatively small room for a studio, but a lot of portrait work is done at similar distances. The system gave beautifully even results with both 360's working in tandem as a keylight and hair light, with reflector. I certainly expected the limitations to be somehow more evident. Instead, I turned on the flashes, dialed in an exposure compensation, and went back to work.
The inner ring was a pouring bowl and the outer is a mixing bowl, with the bottoms cut out and a cardboard ring taped in between. The inner surfaces are lined with aluminum foil tape, and a shopping bag makes the diffuser. I wasn't sure how it was going to do with the preflash system, because the preflash from the controller on the K-3 actually bounced off the red backside of the mixing bowl while I shot through the center. I really wasn't sure WHAT the system would think, or if the flash would fail to fire. After the results with the commercial softboxes, it was no shock at all that the system wasn't phased by my DIY ring flash.
The only REAL problem with it is one you have to blame the photographer for: It's a slightly warmer white than the diffuser material on the softboxes, which causes the relatively blueer hairlight to have a sort of moonlight effect, which you may or may not like.
Time for choices
Like it or not, the size and color of the hairlight was the result of my choices. I've actually gone back and forth a couple times, and that's okay. No flash system can automatically adapt for color differences, and that's part of why photographers need to know their equipment inside and out. Those choices, like the position of the light, remain in the hands of the photographer. What the wireless P-TTL does is provide a reliable way for us to take the math OUT of our hands, to allow me to keep my focus on making those creative choices, which is the time I can spend thinking about other things.
It may not have all the features of Nikon's i-TTL system, but with all the discussions about fully manual radio trigger settings, it certainly offers an alternative for my studio environment. It worked reliably enough that I'm certainly going to test it harder in more challenging environments. Maybe if I moved flashes from being background lights to hair lights to fill lights etc etc constantly I'd be more impressed with the availability of on camera controls. To me though, setting the exposure compensation when I turned them on and set the mode seemed equally trivial.
Time for play
I work hard to convince my clients that not only will they like the products they get from me, but I work hard on the customer experience. I think about things like where I need to be, what other guests are trying to see, and being out of the way but available. I want my clients to know that I am constantly working to be reliable and steady. It's my commitment to my level of effort and customer service that make me a professional, but it's that chance to get a chance to actually play with my equipment, experiment, learn and grow that makes me a photographer. My only real complaint is I can't use my beloved smc-m 50mm without shorting the aperture pins. I'm not entirely sure why we can't just dial in the information P-TTL needs.
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