Two versus four strobes for full-frame

i'm contemplating adding a Canon full-frame to my 7Ds, when the anticipated new model is released. I see its main purpose will be for higher iso shooting and at technical depths. Recognising the shallower depth of field of FX for a given aperture some extra strobe punch may be useful. If so, I could either mount four Z-240s (which I already own) each with a guide number of 24 at 100 iso, or invest in a couple of beefier units (like the Sea & Sea YS-250 Pro which sport a guide number of 32). Is it true to say that four strobes are double the power of two, or is it a non-linear calculation?

I'm quite comfortable diving with four strobes as this is a configuration which I have used with my 7Ds, but for the primary purpose of faster recycling rather than more punch.

Grateful as always for your kind advice. Thanks, Tim

I hesitate to advise an expert, but although four strobes doubles the power, that's just a single f-stop. I can't see that the difference is going to be readily detectable in most images. The extra drag and difficulty of manipulating four strobes to provide modelling and minimise backscatter makes me think it may not be worth the bother. Most of the multiple-strobe set-ups that I've seen have been used out in the weird reaches of macrophotography with odd lenses: Inon's endoscopic lens and fisheyes with teleconverters, for instance.

Have you any examples of images shot with four strobes, and a picture of your rig?

Tim

Hi Tim,

I'm using the recently released INON side-by-side adapter which positions two Z-240 strobe as if a single strobe at the end of a normal articulated strobe arm. The in-board strobe is the 'master' and optically connected to the NA-7D which I shoot in either manual or S-TTL, which the out-board strobe duplicates by nature of its S-TTL connection with the in-board strobe via a short slave cable. As the side-by-side adapter locks the strobe pairs as if a single strobe, manipulation is no more problematical than a single strobe. I've not noticed that control of backscatter is any more problematical with pairs than singletons.

Initially I experimented with this configuration using a ULCS 3-way clamps to 'pair' the strobes but as it allowed the strobes to move independently that added a deal of task-loading at 80 metres. At those sort of depths I presently favour shooting the four Z-240s in S-TTL but I'm sure that with some practise and growing familiarity afforded by NDAC's depths, which I live adjacent to, manual settings will become more instinctive. Its still work in progress...

I do take your point about how a doubling of power relates to exposure and as you quite correctly suggest, the pain may not be worth the gain...

Strobe recycling certainly seems to have been improved and I must get around to quantifying the improvement and I can get a fair old burst off at 2 fps with the 7Ds.

Thanks for taking the time to input to my little project. Tim

PS. I do resemble your remark that I'm an egg-spurt...

Further to my last, an area which I am yet to play with is to configure the pairs, not in the same orientation but using the INON YS adapter, to position them out-facing from one-another by 45 degrees from the centre-line. Assuming a 100 degree spread from a Z-240, this configuration will provide more than enough coverage for a Tokina's FOV or perhaps a Canon 8-15 with a future FX sensor. The potential to independently control singletons in a pair and also left and right pairs may offer some interesting lighting opportunities...

I'll jump in here since I did such a comparison for kicks a few years back. I doubled up Z240 type IIIs and had the 250 Hartenbergers on the other side. I'd say there's at least 1.5 stop difference. Granted the Hartenberger was about 1/3-1/2 stop more powerful than the S&S 250. There's no fight on recycling speed as well since the Harty's recycled in 0.5 secs for full power.

Another issue that is harder to notice unless you shoot a FE on a blank wall at a very closed aperture about 7 ft away, you'll see the double Z240 beam, even with the 0.5 diffuser, isn't very even. Not a real issue unless you are trying to light something large and farther back. It a slightly bigger problem when you don't use a diffuser, because the beam reverts to the "T" pattern layout.

I say keep the Z240 and get the 250. For wide angle and faster recycling, bigger is better.

Thanks Drew. You just cost me two grand...

Thanks Drew. You just cost me two grand...

More like $9K if you count the camera and housing. I am looking forward though to seeing what you can do with the new 5D mkIII when it comes out. Best rumors have it being announced the 28th. So it won't be long now.

Cheers,

Steve

Good to see you wade-in Buddy!

Yeah... Maybe I can just get away with the 8-15mm as the 100mm and 10-22 I already have will do the job on FX. But it may be nice to have the Canon EF 16-35mm f/2.8L II USM and then there's always the Sigma 15mm... I feel a haemorrhage coming on!

Just waiting for Eddie to tool for the MkIII...

Take good care and hope all is well with you, Tim

Thanks Drew. You just cost me two grand...

Think of it as helping WP's advertisers. I'd consider the 8-15 over the 10-17 for EFS but not for EF. With EF, probably only 2 focal lengths will be of use, 8 or 15. With the 1D series not having the APS-H crop, there's no advantage to having the 8-15 with the 1Dx, unless you really want that circle look.

The 16-35 II is probably the nicest lens for WA zoom in the Canon EOS range. The good thing about f2.8 is the canon focus is tad faster and more accurate with f2.8 lenses on cross AF sensors. As a EFS lens, it's sorta not here not there. The Sigma 15 has better MFD and a tad sharper but the AF is slight faster in the EF15mm.

A good lens for EF/EFS mix use is the Sigma 12-24. Great for wrecks and architecture topside.

Bu66er! The YS-250 pro has only a 60 metre rating... I expect it'll be good beyond but has anyone taken it deeper?

PS. This helps a little... http://www.rebreatherworld.com/photography...ro-strobes.html