Some possibly stupid auto-flash questions ...

[dmr]

Maybe some of you fine people here can help me out with this beast, and I do mean BEAST! 🙂

To make a long story long ... I found myself this week to be the proud (?) adoptive parent of a huge honking Sunpak 120J-TTL flash unit. For those who might not know what this one is, it's a big flash tube, about the size of a radio tube, in a removable mirrored reflector. I'm thinking it will be just perfect for my Weegee-look experiments but I need a bit of help understanding a few things ...

(Yes, I would RTFM if I had TFM. The guy I got this from doesn't know what happened to TFM and for some reason, www.sunpak.com does not seem to have TFM on line) 🙁

I got the thing working (it had been dropped, but I think most of the problem was the batteries were dead) and it mounts and flashes on the GIII fine (talk about the tail wagging the dog, it's much larger than the camera) but I'm a bit fuzzy on a few of the auto-mode operations.

I understand the main auto function and it looks like it works. If I shoot something very close up it barely winks but if I shoot out the back door it lights up the trees well over 100' away like it's broad daylight, well, for a fraction of a second, that is. 🙂 (It definitely produces quite an audible >>THUMP<< when it fires at full power!)

Anyway, my questions are all related, as to how "smart" the auto on this flash is. I'm using the standard non-TTL auto module.

1. If I tilt the thing upward to bounce light off the ceiling and such, will the auto mode work, or do I need to compensate by opening the lens a bit? If so, what's the rule of thumb here?

2. If I take the reflector off, like to try for a very bright point-source light, is the auto smart enough to sense properly, or likewise would I have to use a fudge factor on the f-stop?

3. Kind of the opposite, if I put a cloth across the reflector, as a diffuser (the flash with the reflector in place normally does look quite harsh) will the auto circuit be smart enough to adjust for this?

Yeah, kind of the same question, but in different contexts. 🙂

Thanks in advance, gang. 🙂 I'm kinda hoping to use this for some Weegee-type people-watching shots at an event next weekend.

 

[Kim Coxon]

Hi,
As long as the sensor is pointing at where the lens is "looking", it should take account of all of your situations. In basic terms, it integrates the ferlected light and when it thinks it has enough for the correct exposure it either switchs off the flash, (thyrister type guns) or in the case of some of the older ones, it dumps the est of the charge.

Kim

1. If I tilt the thing upward to bounce light off the ceiling and such, will the auto mode work, or do I need to compensate by opening the lens a bit? If so, what's the rule of thumb here?

2. If I take the reflector off, like to try for a very bright point-source light, is the auto smart enough to sense properly, or likewise would I have to use a fudge factor on the f-stop?

3. Kind of the opposite, if I put a cloth across the reflector, as a diffuser (the flash with the reflector in place normally does look quite harsh) will the auto circuit be smart enough to adjust for this?

Yeah, kind of the same question, but in different contexts. 🙂

Thanks in advance, gang. 🙂 I'm kinda hoping to use this for some Weegee-type people-watching shots at an event next weekend.

 

[dmr]

As long as the sensor is pointing at where the lens is "looking", it should take account of all of your situations. In basic terms, it integrates the ferlected light and when it thinks it has enough for the correct exposure it either switchs off the flash, (thyrister type guns) or in the case of some of the older ones, it dumps the est of the charge.

Wow, thanks for the quick answer, Kim. I just hit POST and came back and there it was. 🙂

And, that's exactly what I wanted to hear. I'm getting excited to try this out, as long as I don't get arrested for disturbing the peace or something. I think if I try this at full power without a reflector it will attract far more attention that I want. This thing is extremely bright! 🙂

Thanks again. 🙂

 

[Kin Lau]

Like Kim said.

The auto mode works quite well for all 3 situations.

Removing the reflector is called "bare bulb". Works very well in a room with whitish walls, there'll be next to no shadows.

 

[dmr]

Removing the reflector is called "bare bulb". Works very well in a room with whitish walls, there'll be next to no shadows.

Hmmmm ... Now that you say this I can see how it would be. Intuitively I would think that this would give the most harsh shadows, with just a point light source, but I didn't really think of the entire venue being one big reflector.

A guy on one of the other systems just clarified that he used a 5" reflector for his Weegee-style shots, so I think that's what I'm gonna try. He used a Norman bare tube flash that seems very similar to the one I have here.

Thanks. 🙂