ND Filter for outdoor portraits with off camera flash

Hello,

Looking to buy a ND filter for outdoor portraits with a off camera flash.. Would you recommend a 3 stop or 6 stop? Want to be able to shoot at 1.2 - 2.8 and I have an Einstein so no HSS.

Will there be auto focusing issues with the 6 stop?

I’ve found that 3 stop will nearly always allow me to shoot at least 2.8, offer wider. I also have a variable ND that goes up to 8 stops or so. I don’t use it much but did just pop it on to Test for the purposes of posting here. I took it outside on a sunny morning with a lot of reflective snow. Dialed in Max ND using an a6400. I had no problem acquiring focus on anything. My guess is you’d be fine shooting portraits outdoor, bright light, wide open, six stops of neutral density.

I'm curious about this too, as well as the functionality of the viewfinder in full sun with a 6 stop ND on the lens.

Archibald wrote in post #18968091
I'm curious about this too, as well as the functionality of the viewfinder in full sun with a 6 stop ND on the lens.

If it is that bright that you need a 6 stop filter then there will be enough light in the viewfinder to focus etc. however can your eyes adjust between ambient and the viewfinder quick enough? an answer is live view

Mike

Heya,

I use a 3 stop ND on my F1.2 lens during the sunset with strobe/flash. Keeps me from needing more than 1/4000s mechanical shutter, so I can have a little room to spare.

That's assuming you want HSS.

If you are shooting at sync speed (1/200s) you will want the 6 stop to be able to shoot at F1.2~F1.4 in full sun.

Focus should still function if you're outdoors even with the 6 stop. Indoor in low light, that will be a problem with the 6 stop for AF. And at 10+ stops, it's not that easy to AF without good light. My mirrorless cameras, however, do not struggle at all with AF with ND filters in place and I get WYSIWYG real time so I can see the exposure histogram and how things will generally look without much guess work. Love it.

Here's F1.2 in hard late day light. My mechanical shutter was maxxed out at 1/4000th and base ISO, so I had to use a ND filter, and in this case a 3 stop ND was just enough to drop ambient where I wanted it. Flash exposed the subject up. To do the same thing without HSS, I would have had to drop my shutter to 1/200s (1/180s) and I would have needed about 4.5 stops of ND to do the same thing. Or, a single 6 stop ND and just add a stop of ISO (which won't effect image quality, it's still very low) or I could take the shutter down to 1/100s to get the light back. But even with HSS, I still often need ND filters because of F1.2 in sunlight.

I use Marumi, Hoya & Haida ND filters. They're generally inexpensive and upwards of 6 stops I don't see much color cast (you will see color cast with a 10 stop usually a bit). I sold my Lee stuff because frankly these inexpensive but good ones are great. If you want to spend some money look at BreakThrough's options, or B&W, etc. I use Hoya Pro and Haida Pro lately in the 3 stop, 6 stop and 10 stop ranges and like them and they're inexpensive.

IMAGE LINK: https://flic.kr/p/25d8​Qka

Since it's situational, I think getting both would be best. You can get away with 3 stop if the ambient light is lower. For example, the below shot was in midafternoon with a 3 stop ND, but I did have to go to HSS 1/500 since I was using f1.8. You'd need a 6 stop to keep it with-in sync speed.

IMAGE LINK: https://flic.kr/p/2gtx​9Gx

IMAGE LINK: https://flic.kr/p/2hKj​fiw

When I bought my 50mm f1.2 I also bought a 3 stop ND filter (Hoya). I already had a CPL (2 stops) so I find that 2, 3 or 5 stops gives plenty flexibility to avoid HSS or use it minimally. I have the Lee Little Stopper (6 stops) and Big Stopper (10 stops) but keep them for landscapes as they are a bit of a faff at weddings.