Flash Guns

[Andrew W]

As far as bulk is concerned, I guess the nice strobing flashguns aren't tiny, but on the other hand, someone may want to carry one anyway for shots where a flash is needed for freezing action, so how much extra bulk would be involved could vary quite a bit with the situation.

My flashguns (which have the strobe mode) are pretty normal sized for bounce heads (around 5 inches long). I can get two of them with fireflies into a peli 1150 case. There isn't any more bulk than I would normally take on a cave photography trip. The downside is that they aren't particularly cheap though I imagine there are probably cheaper options on the market.

I'd assume that if the RALF concept worked at all for smoothing out water with a lowish number of flashguns (presumably no more than 6-8 at most?), 32 or 64 flashes would do a pretty good job.

But would probably be bigger and far less practical than using a normal bright light (i.e. one that stays on as long as the battery is connected). A car headlight bulb with a diffuser for example.

As for practicality - certainly the SB800 can be programmed to fire the desired number of flashes over the desired period in manual mode such that with a firefly it would fire just as easily as any other short flash. Not sure about the SB600. I know it can fire as a strobe but not sure if it needs extra hardware on the camera to do so - need to play around with it. You might get better results with a car headlight but I wouldn't have thought it would be more practical to use or carry.

 

[footleg]

As far as bulk is concerned, I guess the nice strobing flashguns aren't tiny, but on the other hand, someone may want to carry one anyway for shots where a flash is needed for freezing action, so how much extra bulk would be involved could vary quite a bit with the situation.

Compared to the 32 flashguns or the 64 flashguns? 

As for practicality - certainly the SB800 can be programmed to fire the desired number of flashes over the desired period in manual mode such that with a firefly it would fire just as easily as any other short flash. Not sure about the SB600. I know it can fire as a strobe but not sure if it needs extra hardware on the camera to do so - need to play around with it. You might get better results with a car headlight but I wouldn't have thought it would be more practical to use or carry.

I find in most cases I need the full discharge power of the flashgun to get the correct exposure, so there will be limited opportunities to use multiple bursts from a single gun. Maybe in some close-up work?

 

[potholer]

I thought the '32/64 flashes' fairly obviously referred to the flashes obtainable from a strobing flashgun like Andrew W mentioned.

*If* there were no extra losses resulting from strobing, the total light output of 32 or 64 pulses would be the same as from an all-in-one flash, so non-moving objects in the scene might be illuminated just as much as they would have been with a non-strobing gun. Even for moving water, the average brightness would presumably end up largely as it would have been, albeit with the blurring.

Of course, it may be there are some losses from strobing, but it shouldn't be hard to work out if that is the case - just take 2 still shots, one on strobe and one on full power and look at the results.

 

[francis]

I picked up a Nikon SB600 for ?18.50 today (brand new @ 90% discount at a shop that was closing down).

I assume that with a guide number 30 @ 100ISO it should be powerful enough to be useful in caves?

Am looking forward to trying it underground

Francis

 

[Andrew W]

I picked up a Nikon SB600 for ?18.50 today (brand new @ 90% discount at a shop that was closing down).

I assume that with a guide number 30 @ 100ISO it should be powerful enough to be useful in caves?

Am looking forward to trying it underground

Francis

I use two SB600s as my normal lighting rig underground. The following link contains an album of shots taken in Notts II using various combinations of the 2 flashes.

http://s205.photobucket.com/albums/bb201/andrewwallis/Notts%20II/

I use fireflies with them. If you have certain Nikon model cameras the SB600 is capable of wireless ttl without any slave attachment. Unfortunately, having experimented with the wireless TTL underground, it isn't reliable enough. With the fireflies set off by the camera's inbuilt flash (covered with an infrared filter) it works no problem.

Regarding the strobing on this model, I'm not sure if it can do it without extra gear. I know I managed to get it set up to strobe when fired by a nikon commander unit (part of the wireless system Nikon now uses) but I'm not sure if it will do it when fired as a dumb flash. I know the SB800 can strobe on its own. If you can get one of those for ?20 your laughing 

I thought the '32/64 flashes' fairly obviously referred to the flashes obtainable from a strobing flashgun like Andrew W mentioned.

*If* there were no extra losses resulting from strobing, the total light output of 32 or 64 pulses would be the same as from an all-in-one flash, so non-moving objects in the scene might be illuminated just as much as they would have been with a non-strobing gun. Even for moving water, the average brightness would presumably end up largely as it would have been, albeit with the blurring.

Of course, it may be there are some losses from strobing, but it shouldn't be hard to work out if that is the case - just take 2 still shots, one on strobe and one on full power and look at the results.

This is exactly what I was talking about - 1 flash gun, as many individual bursts as you like provided they don't add up to more than a single full power flash. Certainly when fired like this it looks to the naked eye like one continuous long duration low power flash. As potholer said, provided the camera is stationary and the shutter is open the full duration, 64 low power bursts (of 1/64th full power) provide the same exposure as 1 full power short burst (ignoring any light loss that may or may not arise).

I really ought to go out and try it rather than talking about it  :-\

 

[francis]

I asked if he had an SB800 as well, but sadly he didn't. If he had I would have got both of them. My camera's (Nikon D80) built in flash can be set to commander mode, so I don't need anything extra to set it off remotely. I will experiment later on today and see if I can make it strobe, that would be cool!

I have another flash (Guide nr 20) with a firefly attached, as a secondary flash. I will experiment using the two flashes together next week when I'm going mining.

Francis

 

[antmcc]

I have an SB600 and, that I'm aware of, there is no means of doing strobing, that's one of the benefits of buying the SB800.

For ?20 (you lucky so and so) I'd have bought as many SB600s as they had in the shop, even if you didn't want them it seems there's a ready market here...!

 

[footleg]

I thought the '32/64 flashes' fairly obviously referred to the flashes obtainable from a strobing flashgun like Andrew W mentioned.

*If* there were no extra losses resulting from strobing, the total light output of 32 or 64 pulses would be the same as from an all-in-one flash, so non-moving objects in the scene might be illuminated just as much as they would have been with a non-strobing gun. Even for moving water, the average brightness would presumably end up largely as it would have been, albeit with the blurring.

Ah, my mistake. I thought this was refering to the RALF concept, which I think stands for Redundant Array of Little Flashguns. The idea was that lots of small cheap flashguns could be attached to the one slave unit and fired as one big flash, with options to stagger the firings so that a strobe effect was possible for blurring moving subjects.

I clearly had not thought through the point about multiple flashes from one gun supplying the same light as one complete discharge from the gun. Sometimes the obvious eludes me!

 

[potholer]

Well, the thread did rather veer from Ralf to strobing flashes, and I guess 'flashes' does have the problem of referring both to the objects and what they produce.

 

[francis]

I have an SB600 and, that I'm aware of, there is no means of doing strobing, that's one of the benefits of buying the SB800.

For ?20 (you lucky so and so) I'd have bought as many SB600s as they had in the shop, even if you didn't want them it seems there's a ready market here...!

I'll have a play with it when I get home, but sounds like it isn't possible .

I will be getting an SB800 at some time, but there are other things I want to get first now that I have a flash, like a tripod, pelicase and a Tokina 12-24 f4 wide angle lense.

They only had one, otherwise I too would have bought the lot!

Francis