Using flash with auto ISO?

Since I don't have a compatible flash I can't test it. If you use a compatible flash for example SB-5000 or SB-910 and enable auto ISO how would it work?

My personal experience is never to use Auto ISO at all with a flash, Nikon or third party

 

When I shoot with Auto ISO, the camera will based on my settings (I shoot manual, with preselected aperture and 'film' speed, usully in Matrix mode) select ISO value in order to get a correctly exposed image

 

If I use a flash light, even a SB800 or SB910 (I have both) the camera will still do the same

Unfortunately despite shooting in BL/TTL (flash is kept lower as ambient, more or less s a fill) I usually end up with overexposed flash images despie of that

 

With a third party flash, the BL/TTL mode is absent (In particular the old Metz potatohead Metz 60's I have as third party units) and the above described over exposure flash iremains, and even become more prominent

I just want to know how it would work if at all.

I believe the camera tries to pick an automatic ISO suitable for exposing the background, even in full manual mode (as it would I'm aperture priority), although with some restrictions. There's a thread somewhere around here about what the D7000 did in these circumstances (which changed relative to previous cameras) with descriptions of different bodies. It horrified me with its complexity, and for me it's likely to pick a higher ISO than I want.

 

I usually just turn auto ISO off for flash shooting. However, I notice the D850 has a separate upper ISO limit (if I'm reading it right) you can set for flash photography (ironically, since it lost the D810's integrated flash). This might save me from the times I forget to turn off auto ISO.

 

This might be a rare case where Nikon learned to stop guessing what their users want, and just ask them...

I believe the camera tries to pick an automatic ISO suitable for exposing the background, even in full manual mode (as it would I'm aperture priority), although with some restrictions. There's a thread somewhere around here about what the D7000 did in these circumstances (which changed relative to previous cameras) with descriptions of different bodies. It horrified me with its complexity, and for me it's likely to pick a higher ISO than I want.

 

I usually just turn auto ISO off for flash shooting. However, I notice the D850 has a separate upper ISO limit (if I'm reading it right) you can set for flash photography (ironically, since it lost the D810's integrated flash). This might save me from the times I forget to turn off auto ISO.

 

This might be a rare case where Nikon learned to stop guessing what their users want, and just ask them...

 

thanks but I believe Nikon knows what we want but they just can't please us all.

Oh yes - I believe Nikon knows what some of us wants some of the time.

 

As with most of the electronics industry, where it's really not difficult to have a configuration option, I do think they've often fallen into the trap of, given two valid options, picking the way they most might want something to behave rather than offering both. People use cameras differently.

Update, having checked my D850: there is indeed a separate "maximum sensitivity with flash", but you can't set it to 64, annoyingly.

Sometimes it is best to go auto everything, meaning P mode, Auto ISO and TTL BL Auto FP on flash.

 

There is probably complex calculations about subject distance, background illumination, sensitivity and remaining charge of flash. Usually things work out in an manner that there is image. If You get focusing distance wrong the main subject is probably not correctly exposed.

 

In practice daytime images with flash often are ISO 100, late evening images are ISO 400 and if flash runs low on charge on indoor serie ISO is upped from that 400.

Yes - if I were actively trying to balance for the background, the camera would probably be doing the right thing. My problem is that I'm usually not, and care only about the foreground - but I jump between natural light exposure with auto ISO and flash exposure without, and sometimes forget to cancel the auto ISO.

BeBu, I have been shooting in auto ISO for only the last 9 months for speed work though the feature was on my beloved Nikon D2x from over a decade ago. I shoot matrix and examine the blinkies and the hystograms to assure proper ambient exposure. I set the upper ISO limit to level where noise is manageable in post processing and the image quality is relatively preserved. I don't tend to use auto ISO with macro or land scapes because I want total control to maximize dynamic range by using the lower ISO levels. When shooting auto ISO there are three controls, aperture, shutter speed and exposure compensation though there still remains variability in ISO depending on where you point. With flash I shoot 99% of the time in full manual flash control which is a variable that does not change unless I want to change the the effect of the flash on the camera sensor by stopping down the aperture. Other than the power setting on the flash, aperture is the critical adjustment in flash photography. This is important if I am shooting with a Better Beamer where I don't want to stop down too much or the fill flash will be negated. I can make changes on the fly in manual flash and auto ISO mode as easily as I can dial in exposure compensation if my flash is in ttl mode. It's important to remember that the flash exposure mode (either manual or ttl) and the cameras ambient light exposure are independent of each other. I like total control (thank you Patrick Warburton) but have chosen to use auto ISO as of late because I like the consistent results I get. Adding full manual flash to auto ISO and adjusting on the fly is painless. I shoot with Nikon sb 25, sb800 and sb910 flash units with relatively inexpensive manual radio triggers. Using a flash in ttl with auto ISO is as easy as punching in the settings so I will give it a try this week. If your into nature photography John Gerlach and Barbara Edy have a nice book on nature photography and flash. Good hunting.

BeBu,

I just mounted my Sb 800 Nikon flash directly on the my D2X and my newest Nikon a D500. With auto ISO set to "on" with the flash on manual or TTL the camera reverts to native iso (100 on both the D2x and the D500) and ISO can be adjusted manually but the auto iso doesn't work even though its set to do so. With my third party radio triggers that have been glued to my cameras when I use a flash auto iso continues to work. As well my 25 year old Sb 25 turns off the auto iso when mounted directly to the cameras. So my comments above are not true if you put a Nikon flash directly on the Nikon camera but are true if you shoot with a third party manual only radio trigger. I would imagine that third party flashes would have to be individually tested to see if they make the camera revert to native ISO. BLUF Nikon flashes turn off auto ISO when directly mounted on the camera.

"As well my 25 year old Sb 25 turns off the auto iso when mounted directly to the cameras."

 

- Interesting that the SB-25 is recognised, if only partly, by the D500. I thought Nikon had pulled the plug on film-TTL flashes after the D700.

 

On my D700, mounting an SB-25 enables communication of ISO, aperture and lens focal length from camera to flash, as well as automatically setting the camera shutter to below the X-synch speed.

 

When I bought the D800, I was a bit dismayed to find that there was absolutely no recognition of an SB-25 at all. Nikon had miserably removed that part of the firmware wholesale.

 

So I can see that the D2X will still retain some automation with an SB-25. But the D500?

Rodeo, I am more convinced than ever that full manual strobe is the way to go.

My SB25 and D500 results were the same as yours with the D800 but I incorrectly noted that auto ISO is turned off when shooting with the SB 25. The SB 25 is so decoupled from the D500 that auto iso remains functioning and is not influenced by the SB 25

I realize that the D500 and D2X as well as the SB 25 and SB800 are at opposite temporal ends but since I could potentially use all four combinations I like the simplicity of decoupling my flashed entirely from the camera with radio triggers and shooting the flashes in manual.

I tested 4 combinations below and got 4 different results.

 

SB 25 on D2X

Zoom focal registers correctly on SB 25

 

Proper F stop displays correctly on SB 25 only when shutter release depressed

 

Auto iso turns off when SB 25 is mounted on camera hot shoe even though turned on with custom setting menue B1

 

D2X shutter does not fire with flash set to ttl with SB 25 mounted. Manual seems to expose properly.

 

 

SB 25 on D500

Zoom focal length does not register on SB 25

 

F stop does not display on SB 25

 

Auto iso stays on when SB 25 is mounted on camera hot shoe

 

Camera shutter fires and flash activates in ttl but does properly meter. Manual seems to expose properly.

 

 

SB 800 on D500

Zoom focal length registers correctly on sb800

 

Proper F stop displays continuously on sb 800

 

Auto iso turns off with flash in manual and off with flash in ttl when SB 800 is mounted on camera hot shoe but stays on with the flash in ttl bl.

 

With flash in manual or ttl and the camera in auto ISO the camera fires at Native/Baseline ISO of 100 and can be manually adjusted while in auto iso

 

Flash fires and exposes properly in both manual and ttl

 

 

SB800 on D2X

Zoom focal length registers correctly on SB 800

 

Proper F stop displays continuously on SB 800

 

Auto iso turns off with flash in manual and off in ttl when SB 800 is mounted on camera hot shoe.

 

Auto iso turns on with flash set to ttl bl

 

With flash in manual and ttl and camera in auto ISO the Camera fires at Native/Baseline ISO of 100 and can be manually adjusted.

 

Flash fires and exposes properly in both manual and ttl

Thanks for clearing that up. I suspected the D500 wouldn't recognise the SB-25 in any way.

 

"Rodeo, I am more convinced than ever that full manual strobe is the way to go."

 

- Naturally! :cool:

SB 800 on D500

 

Auto iso turns off with flash in manual and off with flash in ttl when SB 800 is mounted on camera hot shoe but stays on with the flash in ttl bl.

 

Sorry, I've not been following enough to follow the acronym use here. "TTL" presumably means "E-TTL automatic exposure", but I'm lost about "BL".

 

I'm about to try experimenting with my new radio flashes and SB-600s on my D850 (which I could use individually directly on the camera, but I don't own a CLS trigger other than my D810), and I'm curious whether anything I see is different from the official Nikon route. The addition of a flash upper ISO limit on the D850 (is it on the D500?) makes me think the flash behaviour could have changed from my D810. Also, I'm curious what my budget Nissin flash will do to the D850 (I've barely used it, but again it might not act like an on-body official Speedlight.)

 

I rarely have enough time to spend with flash images to get the exposure dialled in with manual flash - I think I'm stuck with shifting auto-exposure unless I spend a lot longer getting used to complex flash rigs.

I just want to know how it would work if at all.

I recently read an old article that explained auto-iso with flash.

The explanation was based on extensive testing since Nikon's documentation does not help much.

 

Unfortunately it depends on which generation of Nikon bodies is in question. The 'get the exposure right' algorithm has changed at least once.

 

And neither neither is a simple-to-state rule, depends on the metering mode, iso range and a few other things..

Nikon flash units have traditionally been closely integrated with compatible cameras. Check specifications for compatibility. Using auto-ISO is no problem. A shoe mounted flash is best used for fill-flash. You might want to set the flash compensation to -1 (3:1 lighting ratio). Newer flash units have a better turn-down ratio, and with matrix metering, are less likely to wash out highlights. I use bounce flash (actually, a diffusing dome pointed vertically) with good results, even in mixed lighting. The best solution to mixed lighting is to place a gel on the flash to match the ambient light (or convert to B&W).

 

If flash is to be the dominant light source, make sure other sources are suppressed, or well under exposed. On-camera flash does not give pleasing results. If you a flash off-camera, or multiple flash units, it is faster and more accurate to use the camera in manual, with trial and error or (best) an incident light flash meter.

Andrew said: "TTL" presumably means "E-TTL automatic exposure", but I'm lost about "BL".

 

- I hope TTL doesn't mean E-TTL, because that's Canon's system!

Nikon's digital TTL flash system is called i-TTL.

 

'BL' stands for Balanced Lighting, or what any normal person would call fill flash. Nikon's speedlights default to TTL-BL, but it can be switched off by changing the camera metering from matrix to spot or CW.

 

In the absence of sufficient ambient light, BL flash acts like ordinary TTL flash (i.e. a bit unreliably IME). Give me auto aperture control anyday.

I asked the question because in the other forum that I was in someone said why not use auto ISO with flash. I don't know if it would work because I don't have any compatible flash. I use my flashes in auto mode and camera in full manual. In fact the EXIF data would say flash does not fire.

The best mode for balancing ambient and fill flash is aperture-priority. A variable shutter affects only the ambient light, whereas a variable aperture affects both equally. If you add auto-ISO to the mix, the exposure is first set by the shutter and/or aperture within limits set in the auto-ISO menu. ISO is then varied to make up the difference. Their flash intensity (variable duration) is determined by the ambient light as measured by the camera.

What's weird is the auto-iso only goes 2 stops more sensitive in some situations, and all the way up in others.

Oops - thanks, Joe, I'm exposing my Canon upbringing. I told you I didn't use flash much! (At least I know the CLS acronym. I have enough trouble remembering both AF-S and SWM, in the context of USM, HSM, USD, etc., and the VR/IS/OS/VC terminology. And Tamron, XGM? Really?)

 

Balanced lighting is what I expected it meant, I just wasn't sure. Spot metering seems like it would ensure that the flash will only care about exposing what I'm pointing at, although since what I'm pointing at is rarely where I want to meter (I tend to use highlight priority and swear about how it's not actually ETTR) I might still have to change my behaviour.

 

That said, I notice the D850 has a new (well, not on the D810) custom e4 option "auto flash ISO sensitivity control" which can choose between the foreground and background. What I'm not quite clear is whether the flash will still be exposing the foreground to match the background, and the ISO will then still be affected by the background lighting. I need to experiment.

 

Executive summary for BeBu: Auto-ISO certainly works with flash, and the D850 seems to have acquired extra options for controlling it (though I've not checked whether all the options are on the D500 and D5 as well). Whether the behaviour is so confusing that you're better off turning off auto-ISO is another matter. :-)

"That said, I notice the D850 has a new (well, not on the D810) custom e4 option "auto flash ISO sensitivity control" which can choose between the foreground and background."

 

- Ho! That sounds like it would be fun to test for fallibility.

 

What if you're pointing the camera through some sort of gap in the foreground? Who does the choosing? You or the camera?

 

Automation is great in its proper place - under full manual control!

Even if I can use it I don't think I would but it's nice to know how it works.