Dan Copeland Loc: Hamilton Ontario Canada

I do a lot of Bird Photography and I use manual Speed and Aperture setting with Auto Iso. This works well with want I want to shoot.

Question is when I attach my flash and use HS flash The Auto ISO goes to 400 and does not deviate from 400 ISO. I have looked to see if there is a setting for Auto ISO with flash Attached but can not find any.

Is this the MAX ISO for flash 400? The main reason for the flash is to get a catch light in the birds eye but it seems I am limited now for BIF .

Any Ideas on how to increase the Auto ISO speed with Flash ?

twowindsbear

Here's my WAG

Stop using so much auto. Choose the ISO, set the shutter to the appropriate flash sync value, auto f-stop, and the TTL flash mode.

Good luck

Dan Copeland Loc: Hamilton Ontario Canada

I only use Auto ISO A and T are set manual

I have used Manual ISO and T and Auto A but wanted to try Auto ISO and Man A & T.

I can use Man ISO Man A and Man T and can Adjust the ISO as high as I want using the Flash . Just wondered if there was a setting to have the auto ISO increase with shutter speed and not lock to 400 ISO when I turn on the flash.

Anyway I am heading out now to do some more experimenting.

Thanks for the Info

Dan C

robertjerl Loc: Corona, California

1/250 and ISO 400 are the flash defaults on 7DII. When you use high speed sync it changes the shutter speed but the ISO is still 400. The flash provides the light so higher ISOs are not needed anyway. If you want the higher ISO so you can use reduced power on the flash, well that is not an option as far as I know.

Dan Copeland Loc: Hamilton Ontario Canada

That is fine for normal flash but trying to highlight a bird in flight during the daylight hours it is not helpful. I did some shooting today and will have a look at the photos to see how the flash behaved using manual ISO and different T and A settings.

Sometimes you just need enough to brighten the shadow area under the wings and add a catchlight

robertjerl Loc: Corona, California

Going all manual is a different kettle of fish. There you are going to have to balance the f stop, ISO and flash power for the conditions. Also they will change with the bird at different distances and the natural light at different strengths and angles. Your best bet is probably to over expose a little and bring it down in PP.
I haven't gotten that far in my flash experiments. I haven't read Peterson's book on flash, just using it as a reference to look things up as I try them.

SharpShooter Loc: NorCal

Dan, ISO 400 is the default ISO when the camera is on Auto ISO and the flash is enabled.
The camera is programmed to do that and you can't do anything about it.

But, once you have the flash on, the ISO doesn't need to change since the light output is now constant.
Yes, I know it changes with distance, zoom etc, but the computer strives to give a consistent, exposure in spite of all of that on ettl. ;-)
SS

Photos by Ken Loc: Rock Port, MO

Change your flash to High Speed Sync and then you can set the ISO to any value you wish. Just remember that your flash power decreases (flash distance to subject) when using HSS. Hope this helps.

amfoto1 Loc: San Jose, Calif. USA

Manual mode + Auto ISO is just another form of Auto Exposure.

Actually, Manual + ETTL flash is also a form of Auto Exposure.

Auto ISO and flash together would be sort of an Auto-Auto mode... pretty much impossible to calculate correctly.

Flash needs a consistent ISO, since that's one of the key controls over the flash's power and reach. You also would normally set no faster than 1/250 shutter speed, too, then use Aperture and adjust your ISO to control the flash distance/power.



Yes... it's simple. Turn off Auto ISO and you can use any ISO you wish.

This is actually a good example of why not to get too rigidly locked into using one exposure mode exclusively... It's another reason you should learn to use all the exposure modes in different situations, where each can have it's advantages.

For "FILL FLASH", such as you describe wanting, use Av or Tv Auto Exposure modes (with Auto ISO off). The flash is automatically dialed down about -1.66 stops in any of the AE modes.

For "FULL FLASH", use full Manual (also with no Auto ISO).

Whether Full or Fill, with most of the Canon flashes (in ETTL mode) you can still dial them up or down as you see fit, either directly on the flash or using Flash Exposure Compensation setting on the camera itself. If you switch to fully Manual mode, the flash will want to fire full power... but you can dial it down to a lot lower output if you want it to only act as fill and to add a catchlight to the bird's eye.

Auto ISO, as it's implemented on the 7DII (with both ability to cap the ISO to prevent it from going to high and can apply Exposure Compensation to it, when needed), can be useful. But in my opinion it's way, WAY overused. However, you'll have to get out of Auto ISO to be able to use other than ISO 400 with flash. I'd recommend you learn to use both fully Manual the other Auto Exposure modes without Auto ISO (whether using flash or not). They are helpful too and can serve better in certain situations.

EDIT: Yes, High Speed Sync (HSS) can be useful at times, too... allowing you to use faster than your camera's native flash sync speed (1/250)... all the way up to it's fastest shutter speed in fact (1/8000).

But, be warned: HSS greatly reduces the flash's reach. The faster the shutter speed, the less reach. Depending upon what flash you're using, some models display their range on the LCD on the rear of the flash (reads out in your choice of meters or feet).

I assume you are using a fairly long telephoto lens... with anything upwards of 200mm on an APS-C camera like the 7DII, you may also want to consider using a Flash Extender, such as the Better Beamer or similar. Those are made to fit many of the more popular flashes and use a Fresnel lens to concentrate the light to give you a lot more reach with flash.... three or four stops' worth of additional distance.... and are great for telephoto work. One thing, the flash's distance scale no longer gives accurate readout when an Extender is installed... but you still get ETTL auto flash exposure.

EDIT: One of the "problems" with flash is that it might limit you to single images... no extended bursts at high frame rates. However, I find that using Fill flash (where the flash isn't giving full power) and boosting the flash's reach with an Extender both often will allow two or three shots in a rapid burst, before the flash needs to pause to recycle. I also use Compact Battery Packs to supplement the batteries in the flash, which make for longer bursts and faster recycling (these only work with the 500 and 600 series Canon flashes... but there are third party supplementary batteries available for use with other Canon series, though they require some modification of the flash).

markngolf Loc: Bridgewater, NJ

I shoot manual and auto ISO for all venues other than some indoor sports.
Mark