Flash and Auto ISO (Page 2): As a Nikon shooter with a Z9 and other Nikon DSLRs, the safest rule to follow is not to use Auto ISO with a Nikon flash. The details can get pretty...

photoman43

As a Nikon shooter with a Z9 and other Nikon DSLRs, the safest rule to follow is not to use Auto ISO with a Nikon flash. The details can get pretty complicated for a forum. My Thom Hogan guides to my Nikon cameras explain all of the details. Other third party guides may do the same.

gvarner Loc: Central Oregon Coast

IDguy wrote:

I didn’t pay attention to shutter speed thinking it doesn’t matter with flash. It certainly does matter for the background exposure. I think I used aperture setting to get the DOF I wanted. That part worked fine.

So it might be better when using flash to use M and set the shutter speed, aperture, and ISO trusting the flash for exposure of the subject. My concern is that the numbers I’d choose first will be too dark for background: 1/200 s, f7, ISO 400. I’ll try that.

Yes, using Manual with flash is the way to go. Indoors with my TTL flash I use Manual, 1/200, F4.5, and ISO at 400. The shutter speed controls the effect of ambient light, the flash controls exposure on the subject. Outdoors I use high speed sync and can use a shutter speed up to 1/8000 to severely darken the background ambient light while the subject is properly exposed.

IDguy Loc: Idaho

Bubbee wrote:

Read your manuals. My SB800 won't do TTL at iso over 1000 and the shutter sync is 250..unless set to Hi speed.

The TTL exposure with the SB700 used ISO over 10,000. The subject exposure was good but noisy because of that high an ISO.

One thing I did notice that puzzeled me was how fast the flash recharged and was ready. Now I know why: because of the high ISO and TTL the flash must have used low power.

Lightroom adjustments helped but didn’t fix. I need to go to my other computer to use Topaz Denoise. It will make them acceptable at least for use on small screens.

Grahame Loc: Fiji

IDguy wrote:

I didn’t pay attention to shutter speed thinking it doesn’t matter with flash. It certainly does matter for the background exposure. I think I used aperture setting to get the DOF I wanted. That part worked fine.

So it might be better when using flash to use M and set the shutter speed, aperture, and ISO trusting the flash for exposure of the subject. My concern is that the numbers I’d choose first will be too dark for background: 1/200 s, f7, ISO 400. I’ll try that.

W.R.T. your comment "My concern is that the numbers I’d choose first will be too dark for background".

With the flash turned off, adjustments you make for the background can be seen in the EVF. For example, if you set speed manually 1/200 (sync), aperture f/7 (or whatever you want for DoF) then adjust ISO to get the background ambient brightness you want. Keeping an eye on ISO level of course.

To make this easy you can dedicate a Fn button to isolate the flash whilst doing this.

Bob from Newport Beach Loc: Newport Beach, Ca

I always preset the ISO to provide the background light intensity that I want for the pictures that I am taking. If I want a dark background, I set in iso 100. If I want a lighter background, I set iso 400 or 800. I never use auto iso with the flash. suggest you shoot a shot before hand to determine what you want the background to look like.

SuperflyTNT Loc: Manassas VA

PHRubin wrote:

Most of my newer cameras have 2 or 3 user presets where I set the parameters. So I set one for flash (all manual including ISO) and one for ambient (all manual except auto ISO). Since much of my photography is of live music performances, both are set for the stage lighting at the venue I frequent most.

It’s rare to find a venue that allows “professional” cameras, much less flash.

jcboy3

IDguy wrote:

Here is a lesson I learned with Christmas pictures... (show quote)

One of the reasons I prefer to shoot weddings with my Nikon gear is that auto ISO works well to provide balanced exposures with subject and background, avoiding the deer in the headlight look. And it does it quickly and automatically so I don't have to fiddle with exposure settings while getting the shot. I limit the maximum ISO, keep exposure compensation separate from flash compensation, and set flash exposure to subject and background. I adjust EC to brighten or darken the background as needed, and FC to brighten or darken the subject. If it's a crowd, I increase EC and decrease FC to better balance front and rear subjects. For one or two subjects, I may do the opposite to get better separation between subject and background. But keep it close so it doesn't have the deer in headlight look.

However, if you are getting really high ISO, your environment is just be too dark for balanced exposures. In which case, I would decrease EC rather than try to ride the ISO.

IDguy Loc: Idaho

Thank you all for the helpful comments. I now have a new plan with flash that will work.

I did read the Thom Hogan article pointed to above. He disses the SB 700 for use with Nikon Zs. I see no issues with that. It works fine.

Grahame Loc: Fiji

jcboy3 wrote:

One of the reasons I prefer to shoot weddings with... (show quote)

Thank you for your description of how you use Flash+Auto ISO in that scenario. I've never used flash with Auto ISO but have now familiarized myself with the options in the Z6 for Subject/Background control and max ISO limiting in the mode.

At times I shoot events that start well before sunrise (nil to minimum ambient) and will be taking candids of participants preparing prior to start in variable light conditions that can change from a reasonably lit hotel foyer entrance, a darker corner of a car park to a dim sky as background.

The objective of course is to get the background reasonably true with the subject well lit. I usually do this by adjusting ISO manually to control the ambient and relying on the TTL (FC if reqd) to get the subject/s acceptably lit and it can work well. Speed of working is important so I'm now going to consider if flash and auto ISO is an option that will work here.