If you want to shoot outdoor portraits with a shallow depth of field using artificial lighting, you are going to run into issues of overexposure due to the limitation imposed by the sync speed of your camera. There are two solutions to this: high-speed sync or using an ND filter, and this great video shows you the workflow using each as well as their respective pros and cons.
Coming to you from Gavin Hoey with Adorama TV, this helpful video will show you the differences between using a flash with HSS and an ND filter. The need for these arises from the fact that most cameras have a sync speed around 1/200 s, which can cause you to overexpose your image when shooting outside with a flash and a wide aperture. Traditionally, ND filters had to be used to cut down on the amount of light passing through the lens, but this came with issues like making it difficult to achieve focus. HSS (or variations thereof) flashes allow you to shoot with any shutter speed you would like, but they come with their own drawbacks, such as loss of power or uneven exposure across the frame. Check out the video above for the full rundown from Hoey.
I think if anything, this video proves the old adage “the right tool, for the right job”. Both the ND filter, and HSS flash methods work well, and there are pro’s and con’s to both.
For me, the immediate con that comes to mind when using ND filters is that, unless you have a VERY high quality filter, such as one by Breakthrough Photography or PolarPro, which have little to no colour cast, you’ll have to be aware to fix any colour casts introduced by the filter in post. The same can be said for a flash whose white balance is off, but these days it’s not that much of an issue.
The con with HSS is (and this was mentioned in the video) loss of flash power in HSS mode. If you own something like a Godox AD400Pro or 600Pro, shouldn’t have to worry much, but even then, depending on the shooting location and lighting, going the ND route could provide better results in balancing ambient light with your subject.
I sometimes like to use an ND/CPL combined filter, as it can help remove any sheen / glare from the subject’s skin when shot with flash, and they happen to have oily or reflective skin highlights, though mileage varies, with the obvious usage limitations of a CPL applying.
Again, use the right tool for the right job, and you’ll get it right each time.
Edison do you ever feel using a polarizer on people takes away their natural skin tone reflectivity?
Absolutely, which is why if and when I use it, I apply it very lightly, as I don't want to take away all of their natural reflectivity, just slightly reduce it if I find it's extreme.
I had a client once who was adamant to have all of it taken off (very oily skin), and when I showed them a fully polarized image, they quickly changed their minds :)
The only thing I would say is HSS chews though battery power and often cuts the power range of the flash. Leaf shutter all the way :-]
That is why there is also H-Sync with special flash heads which have a longer flash duration (1/550s), like the ELB 400 HS flash head for the Elinchrom ELB 400. Check out: https://www.elinchrom.com/learn/hss-hs.html to learn the difference to HSS.
I use leaf shutter camera/lenses with a sync speed of 1/1600 so you actually want a flash duration of less than the shutter speed otherwise you lose power. The built-in flash analyser on the camera can be useful
Yes, but that is a different level, a leaf shutter! Speaking of not so much professional and focal-plane shutters: At an exposure time of 1/1000s, I experienced a small loss of light, but only from 1/2000s on the drop is noticeable. I would not expose faster than 1/2000s, but it is feasible, from 1/4000s and below not really.
Andrew, what leaf shutter lens do you use?
I have several Schneider Kreuznach lenses
Are you shooting large format? MF?
MF
All righty then.