M8 - GNC - and Flash Portraits

[wparsonsgisnet]

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I did a portrait session this past weekend, using the M8, the 24, 35 'lux asph, and the 50 'lux asph.

 

This took place in some friends' house, so I didn't take the roll of paper but did try both an umbrella and bouncing off the ceiling. I ended up liking the bounce from the ceiling the best as it cleaned up the shadows better. For the bounce shots I used a shrouded flash a couple of inches from the ceiling, leaning toward the target.

 

I don't suppose it would surprise anyone here if I said I wish I had taken the paper. The background was not everything I would have desired.

 

This is the first shoot where I used the M8 and flash but did not use modeling lights.

 

We moved a couch about 1/3 into the room so people could sit on it and stand behind it. The entire family included the parents, their 3 sons, their 3 wives, and 3 kids aged 4 weeks to 5 years.

 

When I do a shoot I take a (windoze) laptop with me. This gives me instant file backup and verification, and allows the shootees to see what their expressions look like. We did about 100 shots over an hour and a half in pairs and up.

 

This was the first time I used gnc. I use a Metz 54mz4 with the 3502 adapter. For this shoot I used the off-camera extension and set the flash to do gnc with the M8 set to 1/250 and f4.5. I also use the Quantum 2x2 battery pack. The Metz with the Quantum is enough light to do anything.

 

I don't like the gnc. It uses a preflash to calculate the exposure and I find it annoying. The subjects did not complain but I will use auto next time, also with the extension cable.

 

For the record, I used gnc for the entire shoot, and every picture is correctly exposed. The combo of the M8, Metz, gnc, and the extension cord if you wished, works perfectly.

 

My real problem with the preflash is that it introduces a delay into the picture process, about equivalent to the time it took the D2 to focus. The lighting was fine, but I will use automatic next time so that the flash occurs when I push the shutter. With gnc, the shutter first triggers the preflash and then the flash.

[arminw]

It would be nice if you could show us the pictures ... thanks !!

[wattsy]

I don't like the gnc. It uses a preflash to calculate the exposure and I find it annoying. The subjects did not complain but I will use auto next time, also with the extension cable

 

Not sure why you wouldn't manually set the output if you are using flash in a controlled 'formal' setting. Using GNC (or auto) seems a bit odd to me.

[wparsonsgisnet]

Not sure why you wouldn't manually set the output if you are using flash in a controlled 'formal' setting.

 

Ian, I wanted to try the gnc setting. It works, it's just that it annoys me.

 

In the past, I have always used auto on the Metz with my D2 and M8. I thought I'd see how the gnc bit worked.

[grober]

Thus endeth any interest I might have had in a Metz product IF the bloody thing must use a pre-flash to calculate exposure every time. I had no idea.

 

I can't think of any more annoying or pose defeating procedure than a pre-flash!

 

-g

[marknorton]

Grober, iIt's not the flash, it's the way M8 TTL flash metering works - it cannot measure light coming off the sensor so it measures it coming off the closed shutter with a pre-flash. It's the same with the SF-24D.

 

TTL metering takes account of the lens aperture set - the alternative is to use auto where you have to pre-set the aperture to what the flash says.

[wparsonsgisnet]

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Thus endeth any interest I might have had in a Metz product IF the bloody thing must use a pre-flash to calculate exposure every time. I had no idea.

 

I can't think of any more annoying or pose defeating procedure than a pre-flash!

 

-g

 

JW, the problem was not with the Metz, but with gnc.

 

I preferred, and will return to, the automatic mode with the Metz. This does not use a pre-flash -- and also gives perfect pictures with the M8.

 

There was a previous post on the subject of gnc, in lieu of ttl which the M8 does not do, and I wanted to see how it went. In terms of ttl-like exposure control, the M8 gets it just right. The pre-flash comes with the gnc methodology; there was a similar function on my D2 that I also did not like.

 

I don't care for pre-flash. It has the nice benefit of closing the irises of the subjects' eyes, but it never seems to work psychologically because I find that after the first (pre-) flash, the subjects think the picture process is complete and their expression goes south.

 

So, no problem with the Metz (after waiting for 10 or more years to buy one of these I am in heaven), no problem with the M8, no problem with the exposure control using gnc.

 

Did I say no problem?

[Guest guy_mancuso]

I gave up on the gnc , just don't like pre-flash myself . It takes to long

[wparsonsgisnet]

Here is a shot from Saturday.

 

M8, 24mm @ 5.6, 1/250, Metz 54mx4 in gnc mode, 486 filter, Edmund's Linear LoSat profile, sized for web.

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[lars_bergquist]

I continue to use flash the way I've done up till now. The other day I and my wife went to one of my daughters' home. She and her family live in an early 1900s house in downtown Stockholm, with a ceiling height of about three meters. I used a small non-system flash with a coiled shoe-to-shoe extension cord that I filched from my old Olympus OM system. I reckoned that on ISO 320 I would get about f:5.6, did a test exposure to verify it, and then I could fire away to my heart's content; we got many spontaneous scenes, all beautifully exposed. On manual exposure! This is no longer a gamble without my flash meter because I can check on the exposure immediately. The only thing I needed to know was that I should use 5.6, and 5.6--8 in the kitchen with its much lighter walls. And that I ascertained before I started to shoot. Which I could do with about the same ease as with available light.

 

Either Leica or Metz (probably only a difference of logo) should bring out a system extension cord for the M, quick-like. At present I am however doing just fine on either external auto in the flash shoe, or on manual off camera.

 

The old man from the Age of Flashpowder

 

P.S. I''ve not got my new Mac yet, with USB, so I can't show any pictures. Later, maybe.

[marknorton]

Bill, don't want to split hairs, but the M8 is doing TTL flash metering but before the actual exposure, not during it and by metering off the closed shutter, not (as with the M6TTL/M7) off the film.

 

The pre-flash is a trial run from which the camera figures out the guide number (~ flash duration) required, communicates this to the flash and then fires the flash for real. The flash then fires for the required duration.

 

OTOH, in auto mode, the camera simply starts the flash and it's up to the flash to switch off when its own sensor says the exposure is correct.

 

Cover the sensor in the SF-24D in auto mode and you end up over-exposed. Cover it up in GNC mode and there's no difference.

[lars_bergquist]

Bill, don't want to split hairs, but the M8 is doing TTL flash metering but before the actual exposure, not during it and by metering off the closed shutter, not (as with the M6TTL/M7) off the film.

 

The pre-flash is a trial run from which the camera figures out the guide number (~ flash duration) required, communicates this to the flash and then fires the flash for real. The flash then fires for the required duration.

 

OTOH, in auto mode, the camera simply starts the flash and it's up to the flash to switch off when its own sensor says the exposure is correct.

 

Cover the sensor in the SF-24D in auto mode and you end up over-exposed. Cover it up in GNC mode and there's no difference.

 

Mark, Bill does already know all this. His problem was not with correct exposure (the posted picture proves that) but with the pre-flash that introduced a shutter delay and which disturbs the psychology of a portrait session.

 

For the rest, I agree with Bill. I won't spend one kopek for getting M-TTL!

 

The old man from the Age of Flashbulbs

[wparsonsgisnet]

Mark, tnx for clarifying. Yes, the M8 uses the pre-flash to figure out what the exposure should be with the second flash.

 

In one sense this is ttl because the pre-flash eval is thru-the-lens. However, I think of ttl as the camera controlling things by seeing the final flash and shutting down the flash tube -- like the M6-ttl and M7 do it.

 

Technically, the M8 is doing a ttl exposure, but it's really calibrating with the pre-flash and then sending (I guess) 2 signals to the flash, one to start and one to shut down.

 

In any case, it works perfectly, to provide the correct illumination.

 

As you suggest, the auto mode had the flash unit evaluate the light returned from the subject and the flash sjuts itself down. This requires that the M8 be set according to the readout on the back of the flash, so that the M8 will utilize the light that the flash provides. That is, no controls from the M8.

 

Tnx.

[marknorton]

I think it boils down to the fact that light is not reflected off the sensor in a predictable way - though how the M6TTL/M7 handled different shades of film emulsion I have no idea - so that TTL metering has to be done when there's something better to bounce the light. On a D2x, the light goes through the mirror to sensors in the floor of the lens throat but in that case the pre-flashes are almost invisible and there's no perceptible delay.

 

I don't have a Metz but the brigtness of the pre-flash on an SF-24D doesn't seem much less than the real one.

 

With GNC, my understanding is that a command is sent to the flash to set its flash duration for the next operation so that the camera just has to say "do it" and the flash takes care of it.

 

Where I think GNC comes into it's own is when you want to mix available light and flash - the camera can take account of the available light element of the exposure which the flash cannot.

[peterv]

Bill,

 

take a few test shots if you're going to use A-mode next time you're doing portraits. I've found exposure is spot on while in GNC mode, but with the flash in A-mode, my Metz 54 MZi needs to be on f5,6 when my lens is on f4.

In my experience with the Metz in A-mode you need about one stop exposure compensation.

 

Peter

[Riley]

just a couple of quickies Bill

did you use an IR cut ?

did you use the front flash as well ?

 

cheers

[Riley]

Bill,

 

take a few test shots if you're going to use A-mode next time you're doing portraits. I've found exposure is spot on while in GNC mode, but with the flash in A-mode, my Metz 54 MZi needs to be on f5,6 when my lens is on f4.

In my experience with the Metz in A-mode you need about one stop exposure compensation.

 

Peter

 

I have a 54MZ3 and I use it alternately on my LC-1 and E-300

 

I find AUTO is fine, but often use it manually so as not to risk blowouts, or the need to balance outdoor/indoor light

 

I have a stofen permanently attached, and that somewhat screws up large interior exposures, where i need to remember to use the front flash as well

 

rooms under 6m i use the smaller FL36 on the Oly in TTL, S mode 160 shutter, always good

[wparsonsgisnet]

just a couple of quickies Bill

did you use an IR cut ?

did you use the front flash as well ?

 

cheers

 

Riley, I did use the IR-cut filter; details are above the pix, but I forgot that the iso=160.

 

I did not use front flash because I had the flash leaning forward and only an inch or two from the white ceiling. When I chimped, I liked the light spread.

 

Man, I wish I had put the white paper in the car when I left. When they choose their prints, I'm gonna have some post-processing work ahead of me to fix the background.

 

Considering the delay caused by the pre-flash, I'm pleased to have captured so many shots with good expressions.

[ho_co]

I have a Nikon D200. When I use it for automatic flash, the flash reads ISO and aperture from the camera, sets shutter speed on the camera; fires a pre-flash, then takes the picture.

 

This SOUNDS like the way the M8 works (except for relaying the aperture from the camera); HOWEVER, with the D200 you're unaware of two flashes unless you're looking thru the finder.

 

If you're looking thru the finder, you see the flash just before the mirror snaps up--very surprising for an SLR. But the subject is aware of only one flash because the second one follows the first so closely.

 

So: Is this something that only Nikon can do? Why can't Leica do the same?

 

Thanks.

 

--HC

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[tom0511]

I have used the sf24d a few times with ttl on the M8 and I also do not like the delay.

However its sometimes nice to ont have to set the selected f-stop on the flash every time you change it at the camera.

So I think I will use ttl sometimes, but not for occasions when short shutter lag is needed.

I knew the pre-flash would be needed for metering, but I did not expect the lag to be that long before buying the sf24d.

Regards, Tom