The use of flash diffusers

Another poster and I have both given different opinions on when to use a diffuser on your strobes. My thoughts were the diffusers are best used close up, rather than wide angle, in order to achieve an even light without flash reflections. I also suggested that the use for wide angle was not so desirable because of the lose of output.

Another poster has suggest that I am wrong and that the diffusers are primarily for wide angle coverage.

Before I fall on my sword and admit my ignorance, I was hoping for others opinion on their use.

Thanks

Daniel

I am going to have to side with the 'other poster' (for the most part).

I normally leave my diffusers installed when shooting WA, and remove for macro.

But, since I have them attached to the strobes with a lanyard, its easy for me to switch back and forth during the dive depending on the conditions. Sometimes I will only put one on to lower the power from one side of the shot.

It could also depend on your strobes. For some strobes the diffuser is necessary for WA to get the strobe to cover the entire shot area. For macro if your strobe is giving you a noticeable hot spot then a diffuser could be helpful in eliminating it.

Diffusers - a bit of a waste of time in my opinion.

No good for macro as all they do is loose you power.

They do increase coverage in wide angle that's true, but most modern stobes now give around 100 degrees output. They may may also give more backscatter if strobes are not positioned properly.

I used to use a difuser but do not bother any longer.

Yup, FWIW I gave them up on my DS125's which I found both warm enough and wide enough without.

Paul C

It all depends.......

Lighting is a whole subject in itself, but..... try things out (its easy enough to fit diffusers for a shot and then take them off to repeat it). Advice is helpful but cannot replace trying a technique and deciding whether YOU like it or not. I use a single wide beam flash unit with a horsehoe shaped flash tube for macro AND wide-angle, changing its placement to suit the subject and my requirements. This gives me relatively soft lighting, especially on macro. Others prefer the harder illumination provided by a single straight flash tube backed off, others like a 'standardised' twin flash set up which is rarely altered. It depends on YOU and what you want to achieve and how you want your images to appear. Diffusers have their place and may or may not be to your taste, but try with and without and decide for yourself. Photography should not be rule bound, prescriptive or formulaic as this risks images becoming homogenous in appearance.

Good questions! Diffusers do many things besides increase the angle of coverage and change the power of your flashes.

They are light modifiers, similar to the umbrellas and soft boxes that studio photographers use - just smaller. They basically work by changing the "size" of your flash tube to whatever size the diffuser is and they also make the light come from many different directions.

For macro, if you bring your strobe very close to the subject, and have a 4" diffuser on your flash, then you are basically sending a "wall" of light at the subject. This really softens shadows. If you use no diffuser and bring your strobes way back then you are sending a point source light at the subject. This results in very hard line shadows.

It's up to you to control the light and decide which effect you want. The same goes for wideangle, but not to the same degree, since the strobes are usually further back.

I hope this helps, great question!

Cheers

James

What would be interesting to me as a beginner would be to have some examples from the more experienced photographers on the site with "anonymous" strobe information. Then see if there is a consensus of opinion on how the lighting was achieved before the actual technique is revealed.

Guess the lighting coming right up - check for a new thread.

Cheers

James

Thanks for the input on the difusers James. Nice little bit of info regarding positioning of the strobes with/without the difusers.

Can we achieve a concensus of opinion regarding whether the use of a difuser actually increases or decreases the effect of 'backscatter' from two identical pics taken under same conditions at same time?

Will there be more or less 'backscatter' if the difuser is fitted or removed?

Thanks for your help on this...

Bruce

Will there be more or less 'backscatter' if the difuser is fitted or removed?

I found that with good strobe placement, I in very murkey water, diffusers will increase backscatter a little bit, but what is more important is what is mentioned above regarding what sort of lighting you want for a particular picture.

IMHO, diffusers are crucial for shooting shiny fishes and such, since they soften the light and reduce the glare.

For macro my strobes put out enough light to compensate for the half stop or so that the steal. So if I want the soft effect, I just snap them on. For WA, if I need the extra half stop, I'll take them off.

I tether them on a short wire on my strobe arms to make it easy to switch on and off.

just my 2 cents.

john