Fill flash technique

jab2980 · 05-07-2015, 08:56 AM

Originally posted by RAART

if you use center focus point only you will be able to lock the exposure however to use flash manually on the hot-shoe I think that you have to set camera to manual flash and than control it from there, but to able to control flash from camera the flash has to use P-TTL mode. Maybe this is what it is happen to you. The solution what I would recommend is to use flash of camera with wireless triggers (like cowboy studio) and it will work how you wanted but remember you cannot exceed max sync speed of 1/180s. You can use your Sigma flash in full manual mode when attach to those receiver and then experiment from there how much power you will need for fill in or use the light meter (like Sekonic) to get it right... it will work for sure.

Here is an example when I was hiking with an older friend and I had only flash and remote triggers in my bag and had to improvise to light him up as he was in complete shadow... I locked the exposure to the background and with guessing the amount of flash power was able to get it right at the beginning with second try and later when I knew the flash power and distance right away... not the fill flash exactly but this was done with only one flash off camera and wireless triggers...

on this example you can see according to hard shadows from where the flash was firing... I wish that I had second flash with me to soften the hard shadows on the opposite side but I did not plan to make any photos of this kind and it just happens that he wanted the photos and as a good friend I did it for him...

I was thinking of investing in triggers anyhow, so this might do it. Your photo examples are exactly what I was attempting, also. I'm not sure if you did, but I use a ND filter to give me room to work with at 1/180 or less.

enoeske · 05-07-2015, 09:18 AM - **1 Like**

So I tried this out last night. K-3 with the AF540ii. When in Av mode, my flash did indeed switch from M to P-TTL. I don't think it should do that but it seems like this is typical behavior. That being said, P-TTL with HSS on works perfectly fine for fill flash. I usually just set it to -2 compensation and let it do its thing.

jab2980 · 05-07-2015, 11:04 AM

Originally posted by enoeske

So I tried this out last night. K-3 with the AF540ii. When in Av mode, my flash did indeed switch from M to P-TTL. I don't think it should do that but it seems like this is typical behavior. That being said, P-TTL with HSS on works perfectly fine for fill flash. I usually just set it to -2 compensation and let it do its thing.

That's great to hear - thanks for helping me research this. One interesting thing I noticed is that the on-flash compensation (I'm able to adjust between -3 and +1) has zero effect when in HSS mode on my flash. When it's in normal PTTL mode it works as expected. The on-camera EV compensation does work when in HSS, though. Do you notice the same with your flash?

RAART · 05-07-2015, 01:20 PM

Originally posted by jab2980

I was thinking of investing in triggers anyhow, so this might do it. Your photo examples are exactly what I was attempting, also. I'm not sure if you did, but I use a ND filter to give me room to work with at 1/180 or less.

I did not use any ND filter as it was not necessary for me. While I shot in shutter priority mode and let the camera worries about actual f-stop (maybe in very bright sunlight I will need ND filter however I just like to stop lens down rather than using filter) the only thing that I was paying attention is to lock the exposure on the background before I recomposed and to set the flash power accordingly... for the background I will take care in the post-processing first if anything has to be taken care off. The triggers are very cheap $25 for a set of two receivers and 1 trigger. I do not need greater distance than they are capable off but I will consider others if your working distance should be greater than 15-20 meters, even planing to get other triggers but did not set my mind yet which ones.

MadMathMind · 05-07-2015, 03:07 PM

Originally posted by geru2000

I'm a little confused, is your flash set to HSS, if so then 1/2000 shouldn't be a problem for the flash.
The shadows on Haley's face aren't caused by the flash performance nor would the flash be able to remove them properly. Using a scrim or even turning her 180 would probably have removed them. The shadows are not unlike dappling found sometimes when under trees.

The flash fired. But the guide number at 1/2000 and the zoom setting used is 15.84 ft. I was at f/2.2, so that gives a range of about 7'. I'm sure I was quite a bit farther away than that, probably 14' or more. Basically, my flash didn't do anything. If I had shot at 1/500 instead, then I would have been in the clear.

Here she is rotated about 90º:

Exposure: 1/5000

Still shadows. (180 would be worse, since the sun would be right into the camera, then. I think that's where it was.) Shot just minutes earlier, I was a little closer to this subject and had a shutter speed of 1/500:

Here's Harley and Black Widow again. Taken from more or less the same spot (same angle, although Widow was farther from the building by a bit) 5 minutes apart:

Exposure: 1/8000 spacespacespacespace spacespace spacespace spaccecee Exposure: 1/400

I'm pretty sure I was closer to Harley as well, since I wanted her hammer to be out of focus. Still, Harley has shadows. I'm still a novice with my flash but I'm pretty sure its the shutter speed. At 1/8000, the guide number at f/2.2 is like 3' and I was definitely farther than that away.

Quote:

Anyway some nice and colorful shots.

Thank you!

amoringello · 05-07-2015, 03:11 PM

Originally posted by jab2980

Is it common for an external flash to automatically switch from manual mode to P-TTL when shooting in AV mode? I was shooting an outdoor session and attempting to use my flash as a fill in AV mode, however as soon as I focused the shot (and the camera exposed), the flash automatically switches to PTTL mode. Is this a feature/bug of the flash or is this a user error in that manual flash always requires manual mode on the camera. My mindframe is that I'd like the camera to expose on my subject, and I'd like the flash only to flash at enough power to lighten the shadows on a face or to have the catch light show up in their eyes. Forgive me if I'm doing something stupid - I'm not new to my camera or photography but I am new to flash photography.

The flash is not in constant communication with the camera. That would use a lot of battery.
And as such, they don't really know what to do unless told.

The flash will go into PTTL when the camera sends communication signals to the flash. This is done when the camera gets its metering information (usually along with focusing).

After some timeout period the flash may go into whatever default mode it understands.
This is often not PTTL.

I will see similar behavior with Pentax AF540 and AF360 flashes.
It is disconcerting at times, but seems to be "normal" behavior.

MadMathMind · 05-09-2015, 08:50 AM

Originally posted by amoringello

The flash is not in constant communication with the camera. That would use a lot of battery.
And as such, they don't really know what to do unless told.

The flash will go into PTTL when the camera sends communication signals to the flash. This is done when the camera gets its metering information (usually along with focusing).

AFIAK, this happens when you hit the AF button. (Not sure what happens if you're in MF.) If your flash has a zoom setting on it, zoom your lens. You'll notice that the flash won't adjust until you hit AF.

At least with the Pentax flashes, the flash does nothing while the camera's meter is active. The meter deactivates when you hit AF or half-shutter press.

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05-07-2015, 08:56 AM	#16
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578 Original Poster	Originally posted by RAART if you use center focus point only you will be able to lock the exposure however to use flash manually on the hot-shoe I think that you have to set camera to manual flash and than control it from there, but to able to control flash from camera the flash has to use P-TTL mode. Maybe this is what it is happen to you. The solution what I would recommend is to use flash of camera with wireless triggers (like cowboy studio) and it will work how you wanted but remember you cannot exceed max sync speed of 1/180s. You can use your Sigma flash in full manual mode when attach to those receiver and then experiment from there how much power you will need for fill in or use the light meter (like Sekonic) to get it right... it will work for sure. Here is an example when I was hiking with an older friend and I had only flash and remote triggers in my bag and had to improvise to light him up as he was in complete shadow... I locked the exposure to the background and with guessing the amount of flash power was able to get it right at the beginning with second try and later when I knew the flash power and distance right away... not the fill flash exactly but this was done with only one flash off camera and wireless triggers... on this example you can see according to hard shadows from where the flash was firing... I wish that I had second flash with me to soften the hard shadows on the opposite side but I did not plan to make any photos of this kind and it just happens that he wanted the photos and as a good friend I did it for him... I was thinking of investing in triggers anyhow, so this might do it. Your photo examples are exactly what I was attempting, also. I'm not sure if you did, but I use a ND filter to give me room to work with at 1/180 or less.

05-07-2015, 09:18 AM - 1 Like	#17
enoeske Veteran Member Join Date: Jul 2009 Location: Surprise, Az Photos: Gallery Posts: 2,136	So I tried this out last night. K-3 with the AF540ii. When in Av mode, my flash did indeed switch from M to P-TTL. I don't think it should do that but it seems like this is typical behavior. That being said, P-TTL with HSS on works perfectly fine for fill flash. I usually just set it to -2 compensation and let it do its thing.

05-07-2015, 11:04 AM	#18
jab2980 Pentaxian Join Date: Apr 2013 Location: Pittsburgh, PA Photos: Albums Posts: 578 Original Poster	Originally posted by enoeske So I tried this out last night. K-3 with the AF540ii. When in Av mode, my flash did indeed switch from M to P-TTL. I don't think it should do that but it seems like this is typical behavior. That being said, P-TTL with HSS on works perfectly fine for fill flash. I usually just set it to -2 compensation and let it do its thing. That's great to hear - thanks for helping me research this. One interesting thing I noticed is that the on-flash compensation (I'm able to adjust between -3 and +1) has zero effect when in HSS mode on my flash. When it's in normal PTTL mode it works as expected. The on-camera EV compensation does work when in HSS, though. Do you notice the same with your flash?

05-07-2015, 01:20 PM	#19
RAART Veteran Member Join Date: Apr 2013 Location: Oakville, ON Photos: Gallery Posts: 1,095	Originally posted by jab2980 I was thinking of investing in triggers anyhow, so this might do it. Your photo examples are exactly what I was attempting, also. I'm not sure if you did, but I use a ND filter to give me room to work with at 1/180 or less. I did not use any ND filter as it was not necessary for me. While I shot in shutter priority mode and let the camera worries about actual f-stop (maybe in very bright sunlight I will need ND filter however I just like to stop lens down rather than using filter) the only thing that I was paying attention is to lock the exposure on the background before I recomposed and to set the flash power accordingly... for the background I will take care in the post-processing first if anything has to be taken care off. The triggers are very cheap $25 for a set of two receivers and 1 trigger. I do not need greater distance than they are capable off but I will consider others if your working distance should be greater than 15-20 meters, even planing to get other triggers but did not set my mind yet which ones.

05-07-2015, 03:07 PM	#20
MadMathMind Veteran Member Join Date: Dec 2013 Location: Houston, TX Photos: Gallery Posts: 1,717	Originally posted by geru2000 I'm a little confused, is your flash set to HSS, if so then 1/2000 shouldn't be a problem for the flash. The shadows on Haley's face aren't caused by the flash performance nor would the flash be able to remove them properly. Using a scrim or even turning her 180 would probably have removed them. The shadows are not unlike dappling found sometimes when under trees. The flash fired. But the guide number at 1/2000 and the zoom setting used is 15.84 ft. I was at f/2.2, so that gives a range of about 7'. I'm sure I was quite a bit farther away than that, probably 14' or more. Basically, my flash didn't do anything. If I had shot at 1/500 instead, then I would have been in the clear. Here she is rotated about 90º: Exposure: 1/5000 Still shadows. (180 would be worse, since the sun would be right into the camera, then. I think that's where it was.) Shot just minutes earlier, I was a little closer to this subject and had a shutter speed of 1/500: Here's Harley and Black Widow again. Taken from more or less the same spot (same angle, although Widow was farther from the building by a bit) 5 minutes apart: Exposure: 1/8000 spacespacespacespace spacespace spacespace spaccecee Exposure: 1/400 I'm pretty sure I was closer to Harley as well, since I wanted her hammer to be out of focus. Still, Harley has shadows. I'm still a novice with my flash but I'm pretty sure its the shutter speed. At 1/8000, the guide number at f/2.2 is like 3' and I was definitely farther than that away. Quote: Anyway some nice and colorful shots. Thank you!

05-07-2015, 03:11 PM	#21
amoringello Veteran Member Join Date: May 2008 Location: Virginia, USA Photos: Gallery Posts: 1,562	Originally posted by jab2980 Is it common for an external flash to automatically switch from manual mode to P-TTL when shooting in AV mode? I was shooting an outdoor session and attempting to use my flash as a fill in AV mode, however as soon as I focused the shot (and the camera exposed), the flash automatically switches to PTTL mode. Is this a feature/bug of the flash or is this a user error in that manual flash always requires manual mode on the camera. My mindframe is that I'd like the camera to expose on my subject, and I'd like the flash only to flash at enough power to lighten the shadows on a face or to have the catch light show up in their eyes. Forgive me if I'm doing something stupid - I'm not new to my camera or photography but I am new to flash photography. The flash is not in constant communication with the camera. That would use a lot of battery. And as such, they don't really know what to do unless told. The flash will go into PTTL when the camera sends communication signals to the flash. This is done when the camera gets its metering information (usually along with focusing). After some timeout period the flash may go into whatever default mode it understands. This is often not PTTL. I will see similar behavior with Pentax AF540 and AF360 flashes. It is disconcerting at times, but seems to be "normal" behavior.

05-09-2015, 08:50 AM	#22
MadMathMind Veteran Member Join Date: Dec 2013 Location: Houston, TX Photos: Gallery Posts: 1,717	Originally posted by amoringello The flash is not in constant communication with the camera. That would use a lot of battery. And as such, they don't really know what to do unless told. The flash will go into PTTL when the camera sends communication signals to the flash. This is done when the camera gets its metering information (usually along with focusing). AFIAK, this happens when you hit the AF button. (Not sure what happens if you're in MF.) If your flash has a zoom setting on it, zoom your lens. You'll notice that the flash won't adjust until you hit AF. At least with the Pentax flashes, the flash does nothing while the camera's meter is active. The meter deactivates when you hit AF or half-shutter press.