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I have read that there are also 3rd party flashes that can be used
w/ Metz SCA 3702 adapter - check here

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it is in russian - but you can see the photo (Regula Variant 740-1 SCA)

[mattdm]

The 54 cannot use the secondary flash in P-TTL, because this small flash bulb cannot fire the necessary pre-flash. So in P-TTL-mode you can only use the main reflector.

The manual says:

Activation of the secondary reflector assigns approx. 85 % of the emittedlight to the main reflector and 15 % to the secondary reflector. These %-values can differ somewhat when shooting with partial light output and secondary reflector.

So I don't think there's actually a secondary bulb.

Anyway, the Metz Auto-mode (Thyristor control, not TTL or P-TTL) is more reliable in its outcome, than P-TTL, especially under difficult conditions (small, bright surfaces in the field of view, which usually leads to heavy underexpsoure with P-TTL) and it is exactly as comfortable, as the camera transfers all parameters to the flash automatically (ISO, aperture, focal length).

My intention is to simply cover P-TTL options. (And, particularly wireless optical P-TTL.) The P-TTL/TTL/Auto debate belongs in a different article.

[mattdm]

it is in russian - but you can see the photo (Regula Variant 740-1 SCA)

Looks like Regula Werk went out of business in the 1980s. So that can go in another article too.

For the curious, here's more info on the history of the SCA system:

http://www.jr-worldwi.de/photo/index.html?ist_DS_internalflash.html#SCA

[Ben_Edict]

The manual says:

Activation of the secondary reflector assigns approx. 85 % of the emittedlight to the main reflector and 15 % to the secondary reflector. These %-values can differ somewhat when shooting with partial light output and secondary reflector.

So I don't think there's actually a secondary bulb.

I have the flash (actually I have two of those) and ofcourse it is a secondary miniature flash bulb. I think the ratio is simply determined by the fact, that both bulbs are powered by the same capacitor. Using a secondary flash bulb as a built-in fill-light has a long tradition with Metz. You will find it in the 45 series, the 50 and 70/76 flash guns too.

Ben

[mattdm]

I have the flash (actually I have two of those) and ofcourse it is a secondary miniature flash bulb. I think the ratio is simply determined by the fact, that both bulbs are powered by the same capacitor. Using a secondary flash bulb as a built-in fill-light has a long tradition with Metz. You will find it in the 45 series, the 50 and 70/76 flash guns too.

Okay, thanks. Makes sense. And that seems simpler to make than mechanically diverting flash power anyway.

[mattdm]

I've updated the article with a few paragraphs on flash duration. Unfortunately the data is very scarce there.

And then I spent the last couple of hours playing with Google Charts in an attempt to present the information in a practical way. Not successfully, yet.

The idea is to make a graph of maximum distance vs. freeze speed (that is, the farthest away the flash will reach with different lengths of flash pulse). This is partially foiled by the lack of a logarithmic scale in google charts (could kludge that; decided not to) and partially I'm not sure about some assumptions for the chart. The goal isn't really to be a complete reference but to present an idea of what one could do with the numbers. What ISO and lens aperture do you think would be most helpful for this purpose? ISO 100 because we want the best quality for our theoretical strobe shots, or ISO 1600/3200 to show maximums? f/1.4 to match the 50mm f/1.4 (but then, should I use the corresponding guide numbers?) or f/2.8?

[Ben_Edict]

I've updated the article with a few paragraphs on flash duration. Unfortunately the data is very scarce there.

And then I spent the last couple of hours playing with Google Charts in an attempt to present the information in a practical way. Not successfully, yet.

The idea is to make a graph of maximum distance vs. freeze speed (that is, the farthest away the flash will reach with different lengths of flash pulse). This is partially foiled by the lack of a logarithmic scale in google charts (could kludge that; decided not to) and partially I'm not sure about some assumptions for the chart. The goal isn't really to be a complete reference but to present an idea of what one could do with the numbers. What ISO and lens aperture do you think would be most helpful for this purpose? ISO 100 because we want the best quality for our theoretical strobe shots, or ISO 1600/3200 to show maximums? f/1.4 to match the 50mm f/1.4 (but then, should I use the corresponding guide numbers?) or f/2.8?

Cannot comment on the technicalities of the graphing, because that is beyond me...

But for the camera settings I would suggest ISO 100 and ISO 400 at max. The problem at higher ISO settings is, that not only will photos show more noise, but at very high ISO settings almost all DSLRs (apart from Nikon FF) show a hefty decrease of their exposure ratio. But a good exposure ratio is key to good flash images, as flash (especially if used in dim light or in the dark) already produces a high contrast lighting.

For aperture I would suggest to use 2.8, because depth of field is tiny at 1.4 and that might be a problem, especially when focusing in dim light - and also with a setting of 2.8 this will be meaningful for the many standard zooms.

Other opinions may differ, ofcourse.

Ben

[mattdm]

Okay, so I added a chart. I think it came out pretty well:


Where the ✖ is a very rough scientific guess.

I also tried to make a chart for just the basic guide numbers, but, uh:



it's not really useful.

[Ben_Edict]

This looks very impressive and I think, it could be useful, too. One point is, that the first curve nicely shows, that the differences between these flashes in terms of light output are pretty small. The second set of curves looks a bit complicated, because these are discrete steps (ofcourse determined by the reflector setting). But I have no idea, how that could be improved. Perhps it would be easier to read, if you could replace the lines with simple x or bullets or something discrete? I have no idea, how complicated this might be, though.

Good work!

Ben

[mattdm]

So, does the non-P-TTL auto mode work in the camera's program modes (that is, anything but M) on Pentax or Metz flashes? This isn't a big drawback or anything — I just want to be able to explain it clearly.

[Ben_Edict]

So, does the non-P-TTL auto mode work in the camera's program modes (that is, anything but M) on Pentax or Metz flashes? This isn't a big drawback or anything — I just want to be able to explain it clearly.

Yes, exactly. The camera transfers all setting information (aperture, ISO and focal length) to the flash. The flash then sets the X-sync shutter speed or - if you allowed slow shutter speed sync - it works with any shutter speed equal or longer then the X-sync. The flash adjusts its reflector matching the focal length (within its limits).

This works with P, Av and Tv and M (apart from choosing the shutter speed) - I have never used the Green Mode, so I don't know how it works then, but I guess it does.

It comes even better. Metz flashes support their own wireless protocoll. So you can use several Metz flash guns (one as master, the others as slaves) and don't have a problem with getting the exposure right. This Metz wireless mode works with the Auto-Thyristor control and with the old TTL flash metering, but not with P-TTL.

Most Metz flashes can be used that way, if equipped with a special SCA adaptor (SCA3083), but the higher spec modells have the master and slave functions built in.

Ben

[Clem Nichols]

Matt:

I'm presently using the AF360 flash for the simple reason that when I purchased my K10D outfit a couple of years ago the on-line dealer didn't list the AF540. I'm considering upgrading for additional power, and based on my interpretation of your very well done article I've concluded that with all things considered, the AF-540 is probably the way to go. Have I concluded correctly? Thanks for your response.

I just found in a different post that you felt that the Metz 58 had more flexibility than the 540, so I guess that would be your choice?


CN

[mattdm]

Matt:

I'm presently using the AF360 flash for the simple reason that when I purchased my K10D outfit a couple of years ago the on-line dealer didn't list the AF540. I'm considering upgrading for additional power, and based on my interpretation of your very well done article I've concluded that with all things considered, the AF-540 is probably the way to go. Have I concluded correctly? Thanks for your response.

I just found in a different post that you felt that the Metz 58 had more flexibility than the 540, so I guess that would be your choice?

Well, it's more flexible and about $80 more expensive. I think it mostly comes down to how much that flexibility applies to what you need.

For example, if you need camera-mounted bounce flash in portrait mode, the AF360FGZ is off the list — but if you intend to mostly use it wirelessly, it's hard to beat the features for the price. On the other hand, if what you need is raw power for the price, the Sigma EF-530 DG ST (non-super) looks pretty good.

Hence the article, really.

[mattdm]

Hmmm. The flash manual indicates that it supports HSS, but the manual for the SCA 3702 adapter says that it doesn't. I'm assuming that means HSS would work on other cameras but not Pentax. Correct?

[Ben_Edict]

Hmmm. The flash manual indicates that it supports HSS, but the manual for the SCA 3702 adapter says that it doesn't. I'm assuming that means HSS would work on other cameras but not Pentax. Correct?

Neither the 54MZ4 nor the 76MZ support HSS (I asked Metz about that and tried it myself), the 45-CL4Digital might (?) support HSS. Apart from that, only the Metz dedicated modells (58MZ...) support HSS.

Ben