Why high ISO with flash?

My Godox 685's do not change the ISO on my A7RIII's. Be sure to update the firmware on your Godox flashes to the latest version.

Farhan23 said:

I'm using a Godox 685S with my A7RIII. I've noticed that even with the flash on, the camera takes pics at very high ISOs e.g. 4000. This naturally brings grains to the image. On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution. Why does A7RIII do that.. and is there any way to change this behaviour?

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Take the camera off auto ISO and set it yourself, based on the actual situation.

It is probably trying to get a good ambient light exposure and trying to add some fill Flash. With this camera, you are better off not using auto ISO.

I think the problem is that there is no "Flash" mode. The default is basically Fill Flash, which gives the idea that ambient light will provide the majority of the illumination. Slow is pretty similar, but with longer exposure times, and Rear does kind of the same as Fill, but with rear curtain synch.

I just did some quick tests and found that I got better illumination and exposure (less wash out) with fixed 100 ISO than allowing the A7II to pick its own ISO (it picked 1600).

SQLGuy said:

I think the problem is that there is no "Flash" mode. The default is basically Fill Flash, which gives the idea that ambient light will provide the majority of the illumination. Slow is pretty similar, but with longer exposure times, and Rear does kind of the same as Fill, but with rear curtain synch.

I just did some quick tests and found that I got better illumination and exposure (less wash out) with fixed 100 ISO than allowing the A7II to pick its own ISO (it picked 1600).

Click to expand...

if you are working indoors, ( and if the camera chose ISO 1600, you probably are) then you are better off putting the camera in manual exposure mode. You set the ISO you think you need, you set the aperture you want, and you set the shutter speed to 1/200. That will give you conventional flash coverage.

Farhan23 said:

I'm using a Godox 685S with my A7RIII. I've noticed that even with the flash on, the camera takes pics at very high ISOs e.g. 4000. This naturally brings grains to the image. On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution. Why does A7RIII do that.. and is there any way to change this behaviour?

Click to expand...

I imagine it's programmed that way as it's preferable to include less flash and some ambient light. This avoids it the subject looking like the 'caught in the headlights' look.

phototeacher said:

SQLGuy said:

I think the problem is that there is no "Flash" mode. The default is basically Fill Flash, which gives the idea that ambient light will provide the majority of the illumination. Slow is pretty similar, but with longer exposure times, and Rear does kind of the same as Fill, but with rear curtain synch.

I just did some quick tests and found that I got better illumination and exposure (less wash out) with fixed 100 ISO than allowing the A7II to pick its own ISO (it picked 1600).

Click to expand...

if you are working indoors, ( and if the camera chose ISO 1600, you probably are) then you are better off putting the camera in manual exposure mode. You set the ISO you think you need, you set the aperture you want, and you set the shutter speed to 1/200. That will give you conventional flash coverage.

Click to expand...

Maybe. But my point is that Sony doesn't seem to provide an auto-ISO compatible mode that's designed for situations where you want flash to be the primary source of illumination.

What's the point of have some GN 60 flash if the camera is only ever going to try to use it for fill?

There should be a flash mode that's just called Flash, or maybe Full, where the camera calculates exposure using the full output of the flash, instead of filling in ambient.

--
A7R2 with SEL2470Z and a number of adapted lenses (Canon FD, Minolta AF, Canon EF, Leica, Nikon...); NEX-7 converted to IR.

To me the very first thing to do when using flash is expose for the background by manually setting the camera shutter, iso then adjust the flash power for my subject. Not sure why I would leave the camera Auto ISO but to each its own.

Shoot all in manual exposure in camera and use TTL for flash

be sure flash exposerure compensation is not been set in both flash and camera unless intended

Farhan23 said:

I'm using a Godox 685S with my A7RIII. I've noticed that even with the flash on, the camera takes pics at very high ISOs e.g. 4000. This naturally brings grains to the image. On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution. Why does A7RIII do that.. and is there any way to change this behaviour?

Click to expand...

Shoot in manual. When using lights, I always set my ISO first (usually 100) and, if needed, I will adjust it only after shutter speed, aperture and flash power fail to achieve the result I need.

DoctorKajita said:

Farhan23 said:

I'm using a Godox 685S with my A7RIII. I've noticed that even with the flash on, the camera takes pics at very high ISOs e.g. 4000. This naturally brings grains to the image. On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution. Why does A7RIII do that.. and is there any way to change this behaviour?

Click to expand...

Shoot in manual. When using lights, I always set my ISO first (usually 100) and, if needed, I will adjust it only after shutter speed, aperture and flash power fail to achieve the result I need.

Click to expand...

I'm sure that works great. But sometimes it takes more time than you have, and there's no technical reason why the camera couldn't do that for you (just like all the other things you sometimes let the camera do for you - focus, set shutter speed, or aperture, or WB, or ISO...).

SQLGuy said:

DoctorKajita said:

Farhan23 said:

I'm using a Godox 685S with my A7RIII. I've noticed that even with the flash on, the camera takes pics at very high ISOs e.g. 4000. This naturally brings grains to the image. On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution. Why does A7RIII do that.. and is there any way to change this behaviour?

Click to expand...

Shoot in manual. When using lights, I always set my ISO first (usually 100) and, if needed, I will adjust it only after shutter speed, aperture and flash power fail to achieve the result I need.

Click to expand...

I'm sure that works great. But sometimes it takes more time than you have, and there's no technical reason why the camera couldn't do that for you (just like all the other things you sometimes let the camera do for you - focus, set shutter speed, or aperture, or WB, or ISO...).

Click to expand...

I would argue that shooting in manual is faster/simpler than relying on semi-automatic settings when using artificial lighting, but that’s just me. Expose for ambient then adjust flash power.

--
Instagram: https://www.instagram.com/hodiekajita/

Farhan23 said:

... On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution.

Click to expand...

You're sure about that? Doesn't sound right to me unless you manually set it to 100.

Farhan23 said:

Why does A7RIII do that...

Click to expand...

My experience is that using Auto ISO with flash is a bad idea across all of Sony's model lines.

Farhan23 said:

and is there any way to change this behaviour?

Click to expand...

Change your own behavior instead: Set the ISO manually when using flash.

As said many times, NEVER, EVER use AutoISO with flash (and not only on Sony), it simply doesn't work well along strobes, you are way better doing the old way if you are shooting indoors: Manual, 125-200ms, ISO 400, F4, TTL flash as a starting point and then adjust from there with Flash/Camera EV depending on shooting conditions/ambient light.

Thanks everyone for the replies. The solution seems to be as simple as setting the ISO manually to 100 before shooting with flash!

Regarding A99II, I don't think I've set the ISO manually to 100. It still seems to default to 100 shooting with flash. Will have to confirm that though.

DoctorKajita said:

SQLGuy said:

DoctorKajita said:

Farhan23 said:

I'm using a Godox 685S with my A7RIII. I've noticed that even with the flash on, the camera takes pics at very high ISOs e.g. 4000. This naturally brings grains to the image. On my A99II, whenever I'd use a flash, the ISO would automatically be adjusted to 100 for best picture resolution. Why does A7RIII do that.. and is there any way to change this behaviour?

Click to expand...

Shoot in manual. When using lights, I always set my ISO first (usually 100) and, if needed, I will adjust it only after shutter speed, aperture and flash power fail to achieve the result I need.

Click to expand...

I'm sure that works great. But sometimes it takes more time than you have, and there's no technical reason why the camera couldn't do that for you (just like all the other things you sometimes let the camera do for you - focus, set shutter speed, or aperture, or WB, or ISO...).

Click to expand...

I would argue that shooting in manual is faster/simpler than relying on semi-automatic settings when using artificial lighting, but that’s just me. Expose for ambient then adjust flash power.

Click to expand...

Sounds like we're talking about different things. I'm talking about not exposing for ambient, because ambient is very low, and instead relying on full flash power, which I would have expected the camera to be able to find out from that fancy MI connector.

Metering for ambient is what the camera is doing already.

In a small area, with consistent reflectivity, setting ISO once is pretty fast and easy. Under more dynamic circumstances, not so easy or fast, and, IMO, a wasted opportunity to remove one more technical distraction from the photographer. BTW, this is apparently the default behavior for Nikon CLS with Auto ISO: min ISO, and only increase it if flash power is insufficient. I have yet to see anyone claim that Sony is doing flash handling better than Nikon.

--
A7R2 with SEL2470Z and a number of adapted lenses (Canon FD, Minolta AF, Canon EF, Leica, Nikon...); NEX-7 converted to IR.