Hi,

I have a Powershot S3 with Ikelite housing. The camera has a build-in flash that always has to be popped-out to use it.
The problem is that if the flash is popped-out, it will always flash (I can adjust the flash strength), even if there is enough light.
Is this a problem? And if it is, wil a strobe that funtions as a slave be a solution?

thnx

Hi Johan

Whether you have problems will depend somewhat on what type of photography you are doing.  Compacts are not the best at wide angle shots anyway, and this is probably where being forced to use the flash (in your case) will cause the greatest limitation:  Because the flash is forced on, the camera will set its shutter speed at the flash sync speed (often 1/60th, or sometimes 1/125th).  It then uses its aperture setting in conjunction with the flash to get the exposure correct.  For wide angle shots, the camera will not get much light back from the flash (even if you have a slave strobe), so will tend to go for a wide aperture, which may well be the opposite of what you want.

For macro photography (and general shots up to 1m away or so), you would probably be using the flash anyway (to get the best colours), so being forced to use the flash probably won’t make much difference.

In situations where an ambient light shot would have been possible, the forced flash is of course, wasted battery power, so you will get less endurance from your camera batteries.

A slave strobe won’t solve the forced flash problems outlines above, but will help by providing more light than your camera’s strobe can, so when you want additional light, the strobe will be better than the camera’s flash.

Hope that helps

Graham

Hi Graham,

thanks for the help. Do you know if a EOS 400D has the same problem?

johan

Hello Johan,

Graham is absolutely right, but maybe a slave strobe could fix the solution.
If you use a slave strobe with an optical cable, this one needs to be attached
to housing just in front of the poped-out flash. If you do so, you could tape the
area in front of the internal strobe on the housing around the slave connection,
which would block the internal strobe and only allow the external strobe to fire.
If you then decide, that you would like to should without flash you just disable
the external slave strobe.
I know its not a very beautiful solution, but it should work.

The Canon 400D hasn’t got that problem. you can switch of the flash completely.

/lars

The 400D

Hi Johan

To amplify Lars’ response regarding the EOS 400D a little:  the 400D has a hot shoe which can be used to connect and trigger external flashes / strobes.  As Lars says, you turn off the 400D’s own flash.  The housing typically has a ‘bulkhead’ that allows an underwater strobe to be connected through the housing to the hot shoe (obviously the electronics are entirely sealed!).  Some housing manufacturers (e.g. Ikelite) also include circuitry that (in crude terms at least) converts the TTL signals from the camera to signals that the strobe ‘understands’, enabling the camera to control the strobe as if it were its own flash (or a traditional above water flash).

TTL essentially means that the camera meters the light coming back from the subject (from the strobe), and stops the strobe (quenches it) when correct exposure has been achieved.  Of course, the strobe still has a limited capacity, and once it is fully discharged, no more light is available for that shot, so the ‘magic’ does have its limits.  There is also considerable debate about whether TTL is any good underwater (with dSLRs and external strobes) anyway.  Many photographers are of the opinion they get better results setting the strobe manually.

Finally, as I am sure you are aware, housings for dSLRs are something of a quantum leap up in terms of cost compared to the compact/point and shoot camera housings.

Graham

Well, thank you both for the replies.

About the hotshoe, the Powershot S5 (the upgrade version of the S3) has a hotshoe.

Do you think that all camera’s with a hotshoe can trigger external flashes with for instance Ikelite housings?

yes thats exactly the purpose of the hotshoe or did i misunderstand you?

lars

Nope, you did understand

But as the S5 housing isn’t build yet, I’m questioning if I should sell my old camera and buy an S5 because the hotshoe (as I understand) is a huge advantage..

hi johann,

welcome to our site! I would be interested to read your
posts here once you can report back on the S5 housing.

Hi Johann

A couple of points spring to mind to consider with the S5IS:

- check that the housing has the necessary bulkhead to connect the strobe through to the hotshoe, and also whether the housing includes the necessary circuitry to achieve TTL if that is something you desire.  It’s pretty much a given that such features are included on dSLR housings, but its possible that they may not be present in a point and shoot housing due to price considerations.  Ikelite have made point and shoot housings with bulkheads before though, so its quite possible the S5IS housing will sport the necessary features.  Incidentally, whether the housing has the bulkhead to connect through is the one of the main determining factors in whether a camera’s hot shoe can be used to trigger an external u/w strobe.

- the S5IS has a huge zoom range (36-432mm in 35mm equivalent), and as far as I remember the S3 also had a very long telephoto zoom.  This may mean that you will not have the option of adding wide angle adapters to your rig due to vignetting problems (dark corners appearing in the shots due to parts of the adapter or lens tube getting into the shot.) Vignetting can usually be solved by zooming in a bit, but this has the effect of opposing the very thing you were trying to achieve with the wide angle adapter in the first place, i.e. to get closer to the subject without getting less of the subject in the shot!  Also, the upper end of the zoom is unlikely to be of much use to you underwater (topside is of course a different matter entirely).  If you shoot mostly macro, the zoom limitations are essentially irrelevant to you, but if you hanker after wide angle shots, the S5IS may incurr some unwanted limitations that don’t exist on other P&S;cameras with less telephoto zoom.

If you are buying a camera mainly for u/w use, I would suggest that you think about alternative cameras to the S5IS, however, if you are mainly using the camera topside, with some use underwater where you are happy to be limited to the wide angle of the unadapted camera lens, the S5IS has alot to offer.

Just my 4c worth, and remember, your mileage may differ!

Graham

Andreas Voeltz - 21 August 2007 05:42 PM

hi johann,

welcome to our site! I would be interested to read your
posts here once you can report back on the S5 housing.

No problem!

fishonfilm - 21 August 2007 10:57 PM

Hi Johann

A couple of points spring to mind to consider with the S5IS:

- check that the housing has the necessary bulkhead to connect the strobe through to the hotshoe, and also whether the housing includes the necessary circuitry to achieve TTL if that is something you desire.  It’s pretty much a given that such features are included on dSLR housings, but its possible that they may not be present in a point and shoot housing due to price considerations.  Ikelite have made point and shoot housings with bulkheads before though, so its quite possible the S5IS housing will sport the necessary features.  Incidentally, whether the housing has the bulkhead to connect through is the one of the main determining factors in whether a camera’s hot shoe can be used to trigger an external u/w strobe.

- the S5IS has a huge zoom range (36-432mm in 35mm equivalent), and as far as I remember the S3 also had a very long telephoto zoom.  This may mean that you will not have the option of adding wide angle adapters to your rig due to vignetting problems (dark corners appearing in the shots due to parts of the adapter or lens tube getting into the shot.) Vignetting can usually be solved by zooming in a bit, but this has the effect of opposing the very thing you were trying to achieve with the wide angle adapter in the first place, i.e. to get closer to the subject without getting less of the subject in the shot!  Also, the upper end of the zoom is unlikely to be of much use to you underwater (topside is of course a different matter entirely).  If you shoot mostly macro, the zoom limitations are essentially irrelevant to you, but if you hanker after wide angle shots, the S5IS may incurr some unwanted limitations that don’t exist on other P&S;cameras with less telephoto zoom.

If you are buying a camera mainly for u/w use, I would suggest that you think about alternative cameras to the S5IS, however, if you are mainly using the camera topside, with some use underwater where you are happy to be limited to the wide angle of the unadapted camera lens, the S5IS has alot to offer.

Just my 4c worth, and remember, your mileage may differ!

Graham

Thanks for the advice. I will use the camera mainly topside, but for a couple of weeks a year I will also use it u/w. Do you think that a macro lens is usefull when making macro shots? Or will I get the same problems with a wide angle adapter?
And which strobe should I use if the housing indeed has a bulkhead?

(I’m a #### in u/w photography)

Hi Johann

Ok, macro lens adapters with the S5IS:  I think these will work.  Inon’s macro adapter is designed to allow the camera to focus closer to the lens, so you can get closer to your subject and therefore get the subject larger in the image.  Inon recommend that you use the telephoto setting of the lens.  Normally this would limit how close the camera would be able to focus (most camera’s macro modes work at the wide end of the lens, not the telephoto).  I assume you would not put the camera in macro mode if using an adapter such as Inon’s.

That the telephoto end of the lens is used is advantageous in the situation of the S5IS, because the camera’s lens will be closer to the housing port and adapter glass, so vignetting will be reduced or eliminated, but you will still get close up for the shot.  However, at the telephoto end of the zoom, the focal depth available is more limited than at the wide end.  This means that it is harder to get the subject in focus, and that it is difficult or even not possible to get both the near parts and far parts of the subject in focus simultaneously.

You will almost certainly need a strobe when shooting macro with an adapater, because the housing will be so close to the subject that the port and adapter tend to block the camera’s flash from reaching the subject, or you end up with a big dark patch over part of the image.  An external strobe can be placed to fire past the front of the port and adapter, and thus avoid this shadowing effect.

As regards your choice of strobe, your budget will obviously play a part, although there is a minimum price of entry that is pretty much unavoidable.  Once you are above that threshold, the sky is the limit!  What will probably be the biggest factor limiting your choice of strobe will be what housing you have, and whether it has circuitry to convert the camera’s TTL signals. 

Assuming an ikelite housing with bulkhead becomes available, and that it has TTL conversion circuitry, you would need to get an Ikelite strobe for the TTL to work.  Other strobes can be connected instead, but you will not get TTL - the strobe and camera will need to be set manually - only the synchronisation of the strobe flash and camera taking the shot will happen. 

I don’t know what other housings might be made for the S5IS, but I would imagine that each housing manufaturer would tend to advantage their own strobes rather than competitors!  If Canon release a housing for the S5IS, I would be very surprised if it had a bulkhead for hot shoe connection.  You may find that your decision gets limited to Ikelite housing / Ikelite strobe if you want TTL.

One other thing, and please forgive me if this is obvious to you and I needn’t have mentioned it:  it probably makes sense to start out with your chosen camera and housing, and see what results you get with just that.  If you find you want more illumination, then a strobe is the way to go.  If you have chosen a housing with bulkhead, then TTL controlled strobe is very likely possible.  You will get to find out whether the camera does satisfactory macro for your needs, and if not whether lighting is a problem (solution - strobe!) and/or whether the problem is not being able to focus close enough (in which case, macro adapter!).

Good luck!

Graham