12.06.2017

Pondering the utility of very fast lenses for formal portraits. Hmmm.


Photographed with a Nikon 105mm f2.0 DC lens on a Kodak DCS 760 C camera. 
Early days of digital. 

I'm in love with the idea of using very fast short telephoto lenses to make portraits but I'm a bit conflicted right now about their ultimate utility for more routine, commercial headshots. 

I think it's safe to say that a lot of people love the look of a portrait where the eyes and lips are rendered sharply but the depth of field is so narrow that the background, and indeed, and even parts of the subject just seem to melt way into a fascinating blur.  It's a style that gets a lot of play across the media landscape. 

The easiest way to get the look is to use a longer lens than "normal" and to keep the camera-to-subject distance relatively close. (Not too close or you risk distortion...). The final step is to use the lens as close to its biggest aperture as possible. 

I'll be honest, it's a look I like in a lot of portrait work but I've always had a bit of an issue getting the look just right while using flash. One of the reasons I headed into using so much continuous light over the years, and so often, was to have the ability to dial in just the right f-stop with the easy and nearly endless combination of f-stops and shutter speeds that continuous light sources enable. When I set up studio flash shots I was limited in how wide an aperture I could use by the minimum power setting available in studio flash units,  the intensity of unwanted ambient light, or the limitations of using fast shutter speeds (with focal plane shutters) for flash sync. 

Working at f1.2 or 1.4 with flash just seemed to be a big hassle. Especially when the warm light from my modeling lights polluted the clean, daylight balanced light of the flash. If I turned off the modeling lights then focusing became problematic (yes, even with DSLRs....).

With newer flashes and high FP flash I can work with wider apertures and flash easier now than in the past but I still find it a bit daunting. 

Which brings me to the point of this post: Are fast aperture lenses wasted when doing flash lit portraits? 
I still find that if I use low ISOs and higher shutter speeds I still get alternative light contamination from windows, the modeling lights and the practical lights on the location. The only way around it is to block light sources with black curtains and to dim modeling lights after fine focusing. It's all a pain in the butt compared to shooting with LEDs or even tungsten lights. 

In most situations I'm not interested in using available light to make commercial portraits because most of the light I find just hanging around in modern offices comes from the ceiling and is a mix of "can" lights with compact florescent bulbs mixed with traditional "in the ceiling" fluorescent fixtures. The colors rarely match and in most situations there's also an incursion of blue daylight coming in to make things more interesting (and less controllable). 

But the whole reason to light someone is to sculpt the light and bring dimension to their face. It's also a great way to eliminate all other conflicting light sources. 

In a controlled environment I can choose a high enough shutter speed to kill most non-photographer supplied light sources but if I want to shoot at f1.2 I might need shutter speeds at around 1/250th, even at ISO 100. I guess it's time for me to go through this whole learning cycle one more time....especially now that electronic flashes have gotten so much more flexible and controllable. And now that modeling lights (more and more often) are LEDs that are daylight balanced. And especially now when Olympus and Panasonic are offering lenses with fast apertures that are actually very sharp even when used wide open. 

After doing this for so long it's kind of humbling to go back and re-learn again and again, but that's the nature of the game. 

If you have any secret tricks for shooting portraits with super wide open lenses and electronic flash I really wish you would share them with me. I'll try them out. Anything to keep the work from looking stale.



3 comments:

  1. I prefer the tip of the nose in focus, usually F/1.4 for a small child to F/2.8 for an adult.

    ReplyDelete
  2. I keep a set of high quality ND filters for flash plus fast aperture around 8 stops and I can overpower most other light sources.

    That how I use my f0.95 lenses with flash...

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  3. My (cheap Chinese) studio strobes dim their Halogen modeling lights before firing the flash, and tho the process isn't really happening in an instant, I still didn't get too much 'light pollution' when using normal apertures like around f/4, or even at f/2.8. And yes, I've also used those same studio strobes at f/1.4 (from the distance, bounced, and with our cat on the floor for instance), and that's still a very nice look.

    For humans? I prefer to have at least both eyes in focus, ears are a bonus if done rightly - and ยต43rds makes that far easier than "full frame" Kleinbildfilm = small format film. The best shot of our daughter was taken at f/8 in front of a black background (it's my Flickr header image in case anyone is interested).

    So no, for the studio having f/1.4 or even wider isn't a must have, but it's still nice to have sometimes. But yes, sometimes I also work without or with only 1 modeling (or room) lights for focusing. Works like a charm with both the E-PL5 and E-M10 cameras, and when setting these to 'Live View Boost' (Wrench "D" menu 1 page down in case anyone is looking for that), both the camera's autofocus and I are able to see in the dark...

    Hope that answers the question, and is of any help.

    ReplyDelete

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