External Flash for C700uz

[Tweek]

C700uz users with external flash (HoCL, anyone else??), need your help with some questions!

Which flash unit are u using with your c700UZ? What is the guide number? How much is that proprietary sync cable?

The manual says that when using third party flash, must set the camera in M mode. Is that always necessary? If at the M mode, what is the flash sync speed to use?

Thanks for any reply.

[ckiang]

Quote: Originally posted by Tweek C700uz users with external flash (HoCL, anyone else??), need your help with some questions! Which flash unit are u using with your c700UZ? What is the guide number? How much is that proprietary sync cable? The manual says that when using third party flash, must set the camera in M mode. Is that always necessary? If at the M mode, what is the flash sync speed to use? Thanks for any reply.

I am no Oly user, but here goes.

Typical flash synch speeds of any camera ranges from 1/60 to 1/250 and above. Since digital cameras does not use a focal plane shutter (DSLRs are the exception), you can actually sync at any speed, depending on the effect you want.

Do note that setting flash sync at high speeds in dimly lit situations will give you a very harshly lit subject with near-black background.

My favourite method for indoor flash :
1. Meter the ambient light.
2. Set the shutter speed 2 stops faster than what you get in [1]. e.g. if ambient is 1/15 at f/4, set your camera to 1/60 at f/4.
3. Set the flash on bounced mode and fire.

If you still can't hand hold properly at the "2 stops below ambient", then no choice. Set to the lowest possible handholdable speed and fire. This way, you should get a pretty well balanced flash/ambient exposure.

Regards
CK

[Tweek]

Quote: Originally posted by ckiang I am no Oly user, but here goes. Typical flash synch speeds of any camera ranges from 1/60 to 1/250 and above. Since digital cameras does not use a focal plane shutter (DSLRs are the exception), you can actually sync at any speed, depending on the effect you want. Do note that setting flash sync at high speeds in dimly lit situations will give you a very harshly lit subject with near-black background. My favourite method for indoor flash : 1. Meter the ambient light. 2. Set the shutter speed 2 stops faster than what you get in [1]. e.g. if ambient is 1/15 at f/4, set your camera to 1/60 at f/4. 3. Set the flash on bounced mode and fire. If you still can't hand hold properly at the "2 stops below ambient", then no choice. Set to the lowest possible handholdable speed and fire. This way, you should get a pretty well balanced flash/ambient exposure. Regards CK

wow, CK, thanks, very helpful info. I've been reading up on external flash photography a little, can't say that I understand a lot already, so need to confirm the following:

When most cameras are fixed with the external flash, let's say at A mode, usually the shutter speed is locked at the sync speed. If C700uz insists that M mode is used, means sync speed is not important (as it is an electronic shutter) and any shutter speed can be used.

So let's say in M mode, I set 1/125s, f/8. Then I set the corresponding ISO and f/8 on the flash. Does that mean that when I fire away, the flash intensity will be adjusted to meet the exposure of 1/125s, f/8, for that subject distance? (provided that the flash GN is high enough)

Thanks.

p.s. how are u with the recovery? Hope you've recuperated already.

[ckiang]

Quote: Originally posted by Tweek wow, CK, thanks, very helpful info. I've been reading up on external flash photography a little, can't say that I understand a lot already, so need to confirm the following: When most cameras are fixed with the external flash, let's say at A mode, usually the shutter speed is locked at the sync speed. If C700uz insists that M mode is used, means sync speed is not important (as it is an electronic shutter) and any shutter speed can be used. So let's say in M mode, I set 1/125s, f/8. Then I set the corresponding ISO and f/8 on the flash. Does that mean that when I fire away, the flash intensity will be adjusted to meet the exposure of 1/125s, f/8, for that subject distance? (provided that the flash GN is high enough) Thanks. p.s. how are u with the recovery? Hope you've recuperated already.

You're almost there.

With most cameras, if you set it to Aperture Priority, shutter will be automatically set to sync speed (exception: Canon cameras, which till today, I still find the implementation silly as it's basically "slow sync by default").

In the M mode, assuming you are using an automatic flash (non TTL auto, with the flash's sensor measuring flash exposure) you just have to take care to match ISO and apertures on the flash and the camera. Everything else will be automatic. But obviously not as nice as TTL. But it works.

Regards
CK

P.S. I am doing fine, thanks. Really nice to be connected again.

[Tweek]

Quote: Originally posted by ckiang In the M mode, assuming you are using an automatic flash (non TTL auto, with the flash's sensor measuring flash exposure) you just have to take care to match ISO and apertures on the flash and the camera. Everything else will be automatic. But obviously not as nice as TTL. But it works.

Ok, if I set 1/125s, f/8, ISO100, at 10m from subject. Then I set f/8, ISO100 on the flash. But how does the flash know that I set shutter speed at 1/125s so that it can automatically regulate the flash output to match the exposure? Or does the shutter speed even affect the flash output at all (I think you mentioned before that flash exposure is mainly determined by aperture)?

Ok one last last question:

how much is a typical auto flash unit with hotshoe connection and PC cord connection, and a GN of about 70? Any particular brand/model to recommend (Vivitar, Metz)?

Thinking of getting one for the c700uz and connect via the PC terminal, and using the same one for the S602z (hotshoe) when I do acquire it in the near future. Thanks!!

[mpenza]

Quote: Originally posted by Tweek Ok, if I set 1/125s, f/8, ISO100, at 10m from subject. Then I set f/8, ISO100 on the flash. But how does the flash know that I set shutter speed at 1/125s so that it can automatically regulate the flash output to match the exposure? Or does the shutter speed even affect the flash output at all (I think you mentioned before that flash exposure is mainly determined by aperture)?

Let me try to help The flash won't know your shutter speed setting. If you're using the manual mode for the flash, it'll fire at full strength (or less if there's an option for you to adjust the power). If you're using the auto mode, the flash sensor is supposed to cut off when the exposure is right for the aperture and ISO setting.

I usually use the auto mode. Manual mode requires you to know the distance. For auto mode, there's usually a working range (e.g. 0.7m to 5m) for a given aperture setting.

Think it'll be easier if you could try out

Quote: Originally posted by Tweek Ok one last last question: how much is a typical auto flash unit with hotshoe connection and PC cord connection, and a GN of about 70? Any particular brand/model to recommend (Vivitar, Metz)?

GN of 70 feet or 70m? GN of 70 feet is pretty weak. You'll probably want to get one that's at least 105 feet. GN 70m would be monstrously expensive (and huge). Even the Canon 550EX or the Nikon 28DX is not so powerful.

According to what I read, Vivitar 285HV (GN120 feet, bounce, no swivel, varipower) costs ~$120 in Mustafa. Sunpak 383 (GN120, bounce, swivel, varipower), if you can find it, would probably cost a bit more. I'm using the Metz 32 Z-1 (GN105, bounce, swivel but no varipower) which costs ~$170 for a 1st hand one.

http://www.sunpak.com/383.html
http://www.vivitar.com/Products/Flas...ash.html#285HV
http://www.metz.de/1_metz_2000/m_pag...2_Z-1sync.html

[Tweek]

Quote: Originally posted by mpenza GN of 70 feet or 70m? GN of 70 feet is pretty weak. You'll probably want to get one that's at least 105 feet. GN 70m would be monstrously expensive (and huge). Even the Canon 550EX or the Nikon 28DX is not so powerful. According to what I read, Vivitar 285HV (GN120 feet, bounce, no swivel, varipower) costs ~$120 in Mustafa. Sunpak 383 (GN120, bounce, swivel, varipower), if you can find it, would probably cost a bit more. I'm using the Metz 32 Z-1 (GN105, bounce, swivel but no varipower) which costs ~$170 for a 1st hand one.

Thanks KC! Actually I meant 70m but haha yes realised that it is an overkill. Is your metz better (as in more durable etc) than the other two cos it has a lower GN but more expensive? I don't mind not having varipower, but I want bounce and swivel, say GN105 is enough, about $100-$130. Is the Sunpak the most suitable already, or are there other models to consider? Btw all of them have hotshoe mount and PC cord connection right?

THanks!

[mpenza]

Quote: Originally posted by Tweek Thanks KC! Actually I meant 70m but haha yes realised that it is an overkill. Is your metz better (as in more durable etc) than the other two cos it has a lower GN but more expensive? I don't mind not having varipower, but I want bounce and swivel, say GN105 is enough, about $100-$130. Is the Sunpak the most suitable already, or are there other models to consider? Btw all of them have hotshoe mount and PC cord connection right? THanks!

Dunno whether it's really better or not but it's the only one I found when I went searching for a 2nd hand flash with low trigger voltage. I would probably have gotten the more powerful Sunpak Super 383 too if I could find it. For the Metz flash, I was lucky to find one in good condition and it worked beautifully for me

The Sunpak 383 and the Vivitar 285HV have hotshoe and PC cord connection. The Metz flash, however, has a hotshoe mount but it uses a proprietary PC cord connection. Normal PC cord can't be plugged in. If you want to use it with your Olympus C700, you would need to get a hotshoe that accepts the plug from the Olympus cable. Then you mount the flash on top.

Varipower is very useful!!!! Especially for fill-in flash and close-up shots!

A higher GN is useful too if you want to bounce your flash.

[ckiang]

Quote: Originally posted by Tweek Ok, if I set 1/125s, f/8, ISO100, at 10m from subject. Then I set f/8, ISO100 on the flash. But how does the flash know that I set shutter speed at 1/125s so that it can automatically regulate the flash output to match the exposure? Or does the shutter speed even affect the flash output at all (I think you mentioned before that flash exposure is mainly determined by aperture)? Ok one last last question: how much is a typical auto flash unit with hotshoe connection and PC cord connection, and a GN of about 70? Any particular brand/model to recommend (Vivitar, Metz)? Thinking of getting one for the c700uz and connect via the PC terminal, and using the same one for the S602z (hotshoe) when I do acquire it in the near future. Thanks!!

How the auto flash works is this: The flash does not care (or know) what shutter speed you are using (and aperture for that matter). That's why it's important to set a correct sync speed and match apertures on the flash and camera.

For flash exposure, because the light duration is so short, only aperture matters. Exposure is controlled by the flash (in auto mode), you (in manual) or the camera (TTL) by regulating the duration of the burst of light emitted from the flash.

Like KC said, in Manual mode (on the flash, not on the camera), it will always fire at full power. You gotta set your aperture on the camera based on subject distance and flash GN.

In Auto mode, you set the desired aperture on the camera and the flash. Make sure both matches. When the flash fires, a sensor on the flash unit will measure the light reflected back by the subject. The flash will be cut off once there is enough exposure for that aperture and ISO.

Regards
CK

[Tweek]

I see...truly enlightened already. Now whatever I read in the flash photography book makes sense (they didn't go into the basic theories, just go straight into technicalities). Many thanks to KC and ckiang.

Think I've my eyes set on Sunpak 383 Super. Just sent an e-quotation to CP, hope they do carry that flash. AP's website seems to be down.....

[ckiang]

Quote: Originally posted by Tweek I see...truly enlightened already. Now whatever I read in the flash photography book makes sense (they didn't go into the basic theories, just go straight into technicalities). Many thanks to KC and ckiang. Think I've my eyes set on Sunpak 383 Super. Just sent an e-quotation to CP, hope they do carry that flash. AP's website seems to be down.....

Thought Sunpak flashes are no longer sold in Singapore? I had a hard time trying to buy a Sunpak 433 AF last year. Gave up and bought an used Nikon SB28 instead.

Months after I bought it, I saw it a Cash Convertors for $85. If you can find a used Sunpak 433 AF or 433D from second hand stores or the like, grab it.

Regards
CK

[Tweek]

Quote: Originally posted by ckiang Thought Sunpak flashes are no longer sold in Singapore? I had a hard time trying to buy a Sunpak 433 AF last year. Gave up and bought an used Nikon SB28 instead. Months after I bought it, I saw it a Cash Convertors for $85. If you can find a used Sunpak 433 AF or 433D from second hand stores or the like, grab it.

Oh really ah? Didn't know that.... Ok, next alternative then....Vivitar 285? But no swivel.

[mpenza]

Quote: Originally posted by Tweek Oh really ah? Didn't know that.... Ok, next alternative then....Vivitar 285? But no swivel.

CathayPhoto doesn't carry the Sunpak Super 383 when I inquire last time. I didn't see them in other stores either (Alan Photo, MS Color). It's actually the same as the 433 mentioned by ckiang except that there is no dedication.

Vivitar 285HV is not easy to find too.

[ckiang]

Quote: Originally posted by mpenza CathayPhoto doesn't carry the Sunpak Super 383 when I inquire last time. I didn't see them in other stores either (Alan Photo, MS Color). It's actually the same as the 433 mentioned by ckiang except that there is no dedication. Vivitar 285HV is not easy to find too.

I think Mustafa has the 285HV. At least they do about a year ago.

I've given up on Sunpak already, called Alan, Alley, MS, Cathay, Foto Guide, etc all dun carry.

Regards
CK

[ziploc]

Hi ckiang,

I've got a question: so how to determine what is the correct sync speed for the camera?

What I was trying to do was to use my SB25 in auto mode with my G2. I set the SB25 to auto mode and ISO50 f/4 as on the G2, and tried shutter speed 1/60, 1/125 and 1/250. All were overexposed except 1/250 which was acceptable, but the exposure seems better if I set ISO100 on the flash (with G2 still at ISO50 1/250).

And then another problem is zooming. I am not too sure what to set on my flash when zooming in on the G2. The exposure looks different then in wide angle. If I zoom on the flash, the pic is severely overexposed. If I don't zoom, the result is better but still look overexposed.

Any idea? Thanks.

[ckiang]

Quote: Originally posted by ziploc Hi ckiang, I've got a question: so how to determine what is the correct sync speed for the camera? What I was trying to do was to use my SB25 in auto mode with my G2. I set the SB25 to auto mode and ISO50 f/4 as on the G2, and tried shutter speed 1/60, 1/125 and 1/250. All were overexposed except 1/250 which was acceptable, but the exposure seems better if I set ISO100 on the flash (with G2 still at ISO50 1/250). And then another problem is zooming. I am not too sure what to set on my flash when zooming in on the G2. The exposure looks different then in wide angle. If I zoom on the flash, the pic is severely overexposed. If I don't zoom, the result is better but still look overexposed. Any idea? Thanks.

The G1/G2 has very weird flash implementation, especially if you use Av. Other cameras seem to work fine.

Flash sync speed on focal-plane shutter cameras like SLRs and interchangeable lens rangefinders are between 1/60 to 1/250. On in-lens shutters and electronic shutters like DCs, it can actually be anything. Shutter speed does not affect flash exposure. The manual should state the recommended flash sync speed.

That said, bear in mind that if your ambient light reading requires a shutter speed of say, 1/125 and you are trying to use 1/60, you will get overexposure, flash or not. In that case, lower your aperture.

For the zoom head, either leave it at the widest or match it with your G2's zoom (troublesome). If you are using bounce, then it's an non-issue. If you zoom-in the flash head, the beam of light will be concentrated on your subject, which might cause overexposure.

One more thing, the G2's ISO 50 might not really be ISO 50, but maybe 80. This might cause some discrepancies as well. Which might well explain why you get better results at ISO 100 on the flash.

Rule of thumb for flash exposure:
1. Only aperture controls how much flash exposure is given.
2. Shutter speed has no effect on the flash exposure.
3. Aperture also controls the ambient exposure.
4. Shutter controls ONLY the ambient exposure.

Regards
CK

[Tweek]

Quote: Originally posted by ckiang For the zoom head, either leave it at the widest or match it with your G2's zoom (troublesome). If you are using bounce, then it's an non-issue. If you zoom-in the flash head, the beam of light will be concentrated on your subject, which might cause overexposure.

ckiang, if you have the time and patience, please explain the zoom head thing about flash? That's one thing I don't understand also. Thanks thanks! Paiseh hor.

[mpenza]

Quote: Originally posted by Tweek ckiang, if you have the time and patience, please explain the zoom head thing about flash? That's one thing I don't understand also. Thanks thanks! Paiseh hor.

Taking it simply, a zoom head allows you to control how narrow or wide the light projects. The narrower the light, the further it can reach. Generally, the zoom setting (in mm) for the flash should be the same or wider (smaller in mm) than the camera's zoom setting. On some flash, you can pull the head in or out to adjust the zoom setting. On others, you just push a sliding knob.

ckiang would be able to explain it much better

[mpenza]

http://www.chem.helsinki.fi/~toomas/...q.html#gn-zoom could help too....

[mpenza]

if you're concerned about strobe voltages, you could check this out:
http://www.botzilla.com/photo/strobeVolts.html

I've several entries there as well as "KC".