Indoor flash work for backlit candid shots Q's

[Mike Buckley]

I will certainly be using the camera in manual mode and could use flash in manual, but I'm looking for preferably a faster method where I may be able to leave the flash as is and just concentrate on setting camera exposure.

I don't do enough of this kind of shooting to justify taking the time to trying more than the one method I explained above. Considering that I have to remove the viewfinder from my eye to check the histogram, having done that I can just as easily change the setting on the flash unit as changing the setting on the camera. That's my rationale because it works for me, but a different method of achieving the same results might work better for you.

[Stagecoach]

Update regarding trialing undertaken today using the D800 and SB600 with a scene set up to simulate a child sat at a table with bright daylight behind them from a large window.

The objective was to lower the main exposure so as to not blow out the background and trial lighting the subject with direct, direct diffused, bounced and bounced diffused flash with the camera in manual mode giving me full control to determine speed and aperture (1/250th and between f/5.6 to f/8).

The testing was undertaken with the camera on a tripod to retain the same framing, the flash in iTTL and also TTL BL and the light could not have been better, bright blue sky and a few fluffy clouds

Camera settings were ISO 100, 1/250th and f/4.5, two stops under the cameras suggested in matrix metering. Subject distance was 3.15 m @ 75mm. Examples were shot when using FEC controlled on the camera and also on the flash.

Results were good and generally as expected but surprisingly what it did show up is that whilst FEC functions as you would expect with direct flash, FEC has no affect when the flash is tilted for bounce. I had been expecting I could use FEC in bounce.

But, all is not lost because I have found that in just about any situation I could conjure up with the camera set for the background (e.g. -2EC or -3EC for a very bright window) the bounced flash is giving well balanced results.

This may be the reason why I have achieved good results with this method previously on odd occasions but did not know the reason let alone understand its workings.

Edit : Further consideration of the flash FEC 'appearing' not to work with the flash in bounce mode could possibly have been due to the additional distance of the light plus loss due to dispersion.

The SB-600 manual gives a shooting distance range in TTL mode of 0.7 to 8m at ISO 100, f/4.5, 75mm. I'll take further tests at much shorter distances tomorrow and also the same set up as today using manual flash.

I had based my assumption after a number of tests on the fact that four images shot at FECs of 0, +1, +2 and +3 with all others camera settings locked had absolutely identical exposures.

Another clue is that the various FECs dialed in are showing in the EXIF in View NX as well as it shows when the flash is in bounce.

[Mike Buckley]

Interesting and informative, Grahame. Considering that you were using iTTL and TTL BL modes and, I'm not surprised at the results. That's because those modes are automated and are responding to the larger light source produced by bouncing the flash off the ceiling. The modes in effect are ignoring your flash compensation settings. That also explains why Nikon recommends not using flash compensation or exposure compensation when using the TTL BL mode

I didn't realize that View NX indicates when the flash is being bounced. What is that indication and what version are you using (View NX or View NX-i)?

[Manfred M]

Grahame - your experience with FEC is similar to mine and I simply could not figure out why I was getting the results I was. While I understand how ITTL and iTTL BL are supposed to work (in theory), the variability I get in real life shooting is something I could never figure out. Sometimes just plain EC seems to work and sometimes I needed to use FEC in combination with EC and sometimes FEC alone would work.

Hence my comments on using manual flash. It is also the reason I ended up buying a flash meter. I would set the camera controls so that the background came out well and then added enough flash to light up the subject.

[Stagecoach]

Interesting and informative, Grahame. Considering that you were using iTTL and TTL BL modes and, I'm not surprised at the results. That's because those modes are automated and are responding to the larger light source produced by bouncing the flash off the ceiling. The modes in effect are ignoring your flash compensation settings. That also explains why Nikon recommends not using flash compensation or exposure compensation when using the TTL BL mode

For info, shooting the same subject, direct flash (head not bounced), same settings in both iTTL & TTL BL gave a very minor difference in subject exposure through the FEC range which would be due to the difference in computations in those two modes. The minor difference would be something that would not concern me at all.

I have not come across anything yet suggesting Nikon generally recommend not using any compensation either main exposure or flash exposure in TTL BL mode. I find this surprising as TTL BL mode was their latest mode to supersede iTTL I believe. Much of the advice/discussion I have been reading is from wedding photographers that discuss compensation in depth.

I didn't realize that View NX indicates when the flash is being bounced. What is that indication and what version are you using (View NX or View NX-i)?

I'm using version View NX 2 - 2.10.2 Mike and the info is in the panel on the right side with the shooting data. It shows, camera EV setting, Flash EV setting (as determined by main exposure setting OR computation/summation), Flash EV set on the camera and Flash EV set on the Flash. Below this it it shows the flash is is bounce, but this only shows when it is.

[Stagecoach]

Grahame - your experience with FEC is similar to mine and I simply could not figure out why I was getting the results I was. While I understand how ITTL and iTTL BL are supposed to work (in theory), the variability I get in real life shooting is something I could never figure out. Sometimes just plain EC seems to work and sometimes I needed to use FEC in combination with EC and sometimes FEC alone would work.

Hence my comments on using manual flash. It is also the reason I ended up buying a flash meter. I would set the camera controls so that the background came out well and then added enough flash to light up the subject.

Manfred,

My thoughts at this point are,

a) Is it that my flash is not powerful enough to give me good and controllable results at the distances/settings I anticipate when bounced? (This can be confirmed with further testing).

or

b) Is it that the flash/camera for some reason is not responding to FEC commands when bounced. (I could have a dodgy flash)

Today should reveal more

[Dave Humphries]

Hi Grahame,

Is it that the flash/camera for some reason is not responding to FEC commands when bounced. (I could have a dodgy flash)

If your EC or FEC is in the positive direction; i.e. to obtain more flash light on subject compared to ambient in background, I suspect the reason you see little or no change is because the flash is "maxed out" and cannot deliver the bigger flash pop required.

This is why I use manual, if you set it to max power 1/1 and the pictures aren't bright enough, the cause is obvious, but with iTTL and +FEC/EC, it all happens so quick, you don't see what's happening at the time, you just get unpredictable results.


Since, as you relate, to avoid subject disturbance, both the subject and you will be static for significant periods, this to me suggests Manual exposure and Manual flash power are possible, since flash to subject distance is not going to be changing between shots.


However ...

An alternative method, if you had RF triggering*, would be to mount a flash on a light stand aimed at the ceiling to bounce down on the subject. As I see it, this has several advantages;
a) You have a small RF trigger module on your hot shoe and this does not need repointing 'up' if you change to a vertical (aka portrait) camera orientation for some shots for better framing
b) You can still change the flash power (or FEC) and mode (M or iTTL) from the RF trigger
c) It makes the camera easier to handle
d) It makes you less obtrusive since the flash is not emanating from 'you' (from where the subject is sitting)
e) If the flash is nearer the ceiling, it'll help a bit with reducing the total flash to ceiling & ceiling to subject distances (compared to you down at their height) - but don't get it too close or it won't illuminate a large enough area of the ceiling
f) If the flash (on stand) and subject (at desk/table) are both static, exposure will not change if you change camera to subject distance, even if you're shooting fully manual - e.g. if you move the camera closer or further away during the shoot to control perspective and framing.


* OK, so you don't have an RF trigger or RF flash or light stand, but you could probably get all three (new) for less than half the cost of another (new) SB-600. I'm talking about the Godox/Flashpoint systems, although which flash you get will impact the price. I have TT-685N and IIRC they interface to camera as if they are an SB-600 - and if you're used to controlling your '600 via the camera's menu, I believe you can even do that, rather than use the buttons on the RF trigger (although I find them easier now).

HTH, Dave

[Stagecoach]

Firstly, thanks Dave for the further input on this. I have just completed some further testing and come to a conclusion from the results.

I undertook the same tests (setup, distance, main exposure identical, bounced at same angle, no diffuser etc) as yesterday and also went through the range of manual settings of the flash.

This time I was able to increase the lighting on the subject from the bounced flash in both iTTL and TTL BL (results almost identical) going through the +FEC range. There was however only a minor difference between max FEC achievable and 1 EV below that.

With flash in Manual I ran through 1/8, 1/4, 1/2 and full power settings, only a minor difference was notable between 1/2 and Full power.

The lighting of the subject with the flash at full power was near on identical to that achieved in both iTTL and TTL BL.

The flash is working at it's max in these conditions.

Sorry but have to rush out.........................................

Grahame

P.S. What was different is that I did these tests much earlier in the day, the sun was lower in the sky and the entire light in the room was more balance, less differential.

[Manfred M]

Dave - good writeup.

With the D800 / SB600 combination, an RF trigger is not necessary as Grahame could trigger the flash via Commander mode with the pop-up flash on the D800. Stick the SB600 on a basic light stand (even a jury-rigged one) to get it close to the ceiling and the light from the pop-up should trigger it.

I just tested my D810 / SB600 combination with the SB600 some 10 ft / 3m away and behind me and pointed into a ceiling corner and the setup seems to work fine.

[Stagecoach]

Dave, Manfred

I agree that triggering the SB-600 from a light stand (I have a couple and brackets) would have been an option to overcome the problem but something I would not have wanted to do as I am going to be moving around between rooms somewhat and want to create the least disturbance.

Whilst I think I could have got away with the SB-600s power and achieved acceptable exposures in all modes (manual & TTLs) now clearly knowing it's limitations in this scenario perhaps it would not have been best to work with the knowledge I'm at somethings limitations and have to be very wary of distance. And thanks to Bill for raising this aspect of my initial question.

In addition, diffusers would of had an impact.

So, after being pulled off the computer whilst trying to respond to Dave's post earlier to drop the other half in town that gave me the opportunity to visit the only shop here that partly caters for photographers.

After spending some time discussing and trying to compare GNs of 3 toy models I was coming to the conclusion that I was not going to be able to get anything when out of the blue comes "I don't suppose you would be interested in this monster" and after some digging behind the boxes out pops a Rollei 58.

Back home, a quick charge of it's battery pack, fitted it to the camera, some funny beeps and a coloured screen that said TTL mode, a couple of shots and it works. A quick look at it's rear and there's a knobly dial that I found I could rotate and up comes +- FEC

Next task, read the manual