Flash and auto ISO: I searched the subject but the only one I found was from 2014 so I wouldn't want to bring up an old thread. I didn't use flash and auto ISO until recently because I...

BebuLamar

I searched the subject but the only one I found was from 2014 so I wouldn't want to bring up an old thread. I didn't use flash and auto ISO until recently because I don't have a dedicated flash to my camera. Recently I bought a Nikon SB-800 for my Nikon Df and I found that it does work reasonably well. Not something I use all the time but it works fine.
I found the auto ISO would choose ISO400 when there is the flash. When slow sync is not enabled (which I never do because if I want slow shutter speed with flash I would do it manually) the shutter speed is default to 1/60 (unless you change this default to a different speed or the ambient light if high). This works out fine in most cases as ISO 400 isn't very high for the camera.

User ID

That all makes perfect sense. It would equally make sense with a fixed ISO. Unless I’m missing something in your message. Comment ?

BebuLamar

User ID wrote:

That all makes perfect sense. It would equally make sense with a fixed ISO. Unless I’m missing something in your message. Comment ?

I didn't know how Auto ISO would work with flash. I couldn't find the information in the manual (unless I missed something if you find it please point out to me). So I had to have the flash to figure out what it does and found it's quite usable. I thought if it picks the ISO based on ambient light then it always pick the ISO too high (I have the max limit set at 12,800) because I mostly use the flash when it's dark.

TriX Loc: Raleigh, NC

Glad it worked out for you. I use manual SS and aperture with auto ISO most of the time, but I found that on my Canon, auto ISO and ETTL produced unpredictable results, so it’s one of those time when I now use full manual. Maybe if I had experimented more...

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

BebuLamar wrote:

I searched the subject but the only one I found wa... (show quote)

Congratulations on the SB-800. I have a suggestion when shooting in darker interiors. Turn the head so it aims behind you and angle it up at a 45 degree angle. Use TTL on the flash and manual on your camera. Yes, dragging the shutter at 1/60 or 1/30 of a second is fine. Up the iso to lighten the background to taste.
Good luck and keep on shooting until the end.

joseph premanandan

BebuLamar wrote:

I searched the subject but the only one I found wa... (show quote)

you can use Auto ISO with RAW format but I would check the histogram to see whether your image is over exposed or under exposed. I prefer to use manual flash instead of TTL flash especially for the portraits.

gvarner Loc: Central Oregon Coast

I’m not sure why using Auto ISO would even be an issue with a TTL flash since the flash itself is the controlling factor for exposing the subject. A high shutter speeds reduces the effect of ambient light. The aperture regulates the DoF, and a higher ISO can give you a little more reach with the flash. I’m probably all wet on this but it’s the way that I look at it.

joseph premanandan

gvarner wrote:

I’m not sure why using Auto ISO would even be an issue with a TTL flash since the flash itself is the controlling factor for exposing the subject. A high shutter speeds reduces the effect of ambient light. The aperture regulates the DoF, and a higher ISO can give you a little more reach with the flash. I’m probably all wet on this but it’s the way that I look at it.

if it is a single portrait I use f/5.6 with a shutter speed of 1/125sec or 1/250sec with Is ISO between 400 to 800 and I use manual flash indoor but outdoor I use TTL flash and for group photos I use f/8 or f/11 if necessary and that works for me

bajadreamer Loc: Baja California Sur

BebuLamar wrote:

I searched the subject but the only one I found wa... (show quote)

Although I shoot Canon, I am reasonably sure Nikon is the same. Auto ISO will not work with the flash attached and ON. Even if Auto ISO is selected the camera will default to ISO 400. You can manually set the ISO to anything you want but that will be the ISO used by the camera. I will sometimes keep the camera set to Auto ISO when using a flash because I frequently turn the flash on and off as I primarily use the flash for fill only. When the flash is on, the camera will default to ISO 400; when the flash is turned off, the camera will go back to Auto ISO.

photoman43

I discovered problems using auto iso with Nikon flash on my d850. My Thom hogan guide to the d850 explains the problem in depth. I do not think any of my Nikon flash manuals for the sb800 and sb5000 mention it. I suggest you google Thom hogan Nikon df flash and see what you can find. I no longer use auto iso when I have a flash on my d500 or d850.

PHRubin Loc: Nashville TN USA

FWIW - I wouldn't use 1/60 when using flash. This may cause mixing of ambient and flash lighting. I want the very brief flash to stop action, but the 1/60 is too slow for that on the ambient. I use 1/250, but some cameras are limited to 1/200.

As for auto ISO, since the camera and flash talk to each other for the proper exposure (sorta!), I choose the ISO I want, one that is high enough to not waste flash batteries, but low enough for insignificant noise.

Dan Ausec

gvarner wrote:

I’m not sure why using Auto ISO would even be an issue with a TTL flash since the flash itself is the controlling factor for exposing the subject. A high shutter speeds reduces the effect of ambient light. The aperture regulates the DoF, and a higher ISO can give you a little more reach with the flash. I’m probably all wet on this but it’s the way that I look at it.

no..you are exactly right..no need for auto ISO with any flash use, whether ttl or manual

User ID

BebuLamar wrote:

I didn't know how Auto ISO would work with flash. I couldn't find the information in the manual (unless I missed something if you find it please point out to me). So I had to have the flash to figure out what it does and found it's quite usable. I thought if it picks the ISO based on ambient light then it always pick the ISO too high (I have the max limit set at 12,800) because I mostly use the flash when it's dark.

Okay. If I read you correctly it’s more about curiosity than need or necessity ... kinda the “what if” thing. And it works, and keeps most users out of the weeds.