Using Meters in the Digital Age - FREE Sekoni...

I received my FREE “Using Meters in the Digital Age with Will Crocket” DVD from Sekonic today and just finished watching it. Although its emphasis is around the top end L-558R, I found it helped reinforce what I learned from online sources. The DVD explores three live photo shoots scenarios starting out with a studio shoot then to an outdoor and “on location” shoot.

The host Will Crocket is very articulate and easy to understand. For a FREE DVD, I am very impressed. I highly recommend it to any photographer who is critical about exposure (who isn’t?!). I was stunned to learn that digital slrs have a exposure tolerance of 8/10ths of a stop (Tolerance as in how much adjustments that can be done in post processing to correct for any mis-exposure). It also talks about film, slides, and transparency expsosure tolerances. Quite an eye opener IMO.

You can visit http://www.sekonic.com/DVD/and sign up for the free DVD. It took about a month before I got mine.

Cheers,

Ivan

Monolight Strobes vs. Hot Shoe Flash Units

I have been looking to upgrade my hot shoe flashes (Vivitar 285 HV units which I use off-camera via Pocket Wizards) for some time now. The reason is because I already have a Canon 580EX for on board use and the fact that the 285s are limiting in terms of modifiers and light output power. Seldom do these flashes pack enough juice to shoot sports (fast shutter speeds) during the day or throw the light how I want it. I occasionally jerry rig modifiers out of the crafts bin to get the job done, but I think its time to get more professional and use something more reliable and consistent. Hopefully after selling both Vivitars I can reach the half way mark to affording a moonlight strobe and then eventually a battery pack that goes with it. The price difference is quite apparent, but I think it will easily pay for itself.

Knowing how compulsive I am with buying camera gear, I asked the experts at WheelsandWax, a professional alternative sports photography forum, about the benefits of using bare bulb strobes over the typical hot shoe flash unit just to be sure I wasn’t making an excuse to buy new toys.

Pros and Cons of using Strobes vs. Hot Shoe Flash units (Thanks Ian and Mike at W&W for helping me out):

Pros:
- Light modifiers and attachment options (ie softboxes, grids, etc.)
- Light quality is substantially better with the modifiers as opposed to an unmodified flash
- Recycle Time is usually much faster (great since I am using it for sports)
- Light Output / Power is usually much greater (note: W/s and GN are not equal comparisons)

Cons:
- Weight (Battery and unit are substantially heavier)
- Cost is at least 2X more

Given these pros and cons, I think it’s fair to say that strobes do have more positives then negatives. Doing some window shopping and reading reviews on other various photography forums, I decided to compare the Alien Bee 800 and Paterson Stellar 300 as both are well recommended and in my price range, Sub $300 (Alien Bee offers 10% for students). Below is a comparison chart of the two models. I’ll post an update after I decide which route I take.

Cheers,

Ivan

	The Alien Bees B800 Flash Unit	Paterson Interfit Stellars 300 W/S, Mfr#INT408U
W/s	320 w/s	300 w/s
Flash Duration	1/3200 sec.	1/1000 – 1/3000 sec.
Recycle Time	1 sec. @ full power	1-2 sec. @ full power
Weight	2.9 lb ( 1.3 kg)	4.8 lb (2.2 kg)
Size	9 X 7.5 X 5.5”	12.5 X 4.75 X 8.25”
Attachments / Modifiers	Alien Bee Proprietary	Stellar or Bowen Adaptor, more modifier options
Color Balance	5600K	5200K
Warranty	2 years	1 year
Included	7 inch reflector, flash tube, 100 watt modeling lamp, 15-foot sync cord, 15-foot power cord, nylon clips for gels	Flash tube, Modeling light (INT 499), sync cord, Reflector (RS5003), Power Cord
Cost / Street Price:	$279.95 from Alienbee.com	$214.95 from B&H.com

Flash Power Output and Distance

Flash Power Output and Distance
By: Ivan Wong (ibwphotography.com)

I think its time to go beyond referring to the flash guide table and to understand the fundamentals of what the Guide Number (GN) means and also the distance to flash power output relationship. Any photographer using manual flash/strobes should have these general ideas in mind, especially in action sports when adjustments are made on the fly.

The first point to be discussed is the Guide Number or GN, which is a measurement of a flash unit’s light output. For instance, the Canon 580EX has a GN of 191 whereas a Vivitar 285HV has a GN of 120. The higher the guide number, the greater intensity of the flash. So how can I benefit knowing this? Well the guide number comes from this equation (assuming ISO 100 film):

Guide Number = F/stop X Flash-Subject Distance

Guide numbers are usually given for ISO 100 speed film. Faster ISO settings will require less light so you can shoot at a greater distance. For this reason, you need a different guide number for each ISO setting. Increasing the ISO film speed by a factor of 4 will double the guide number. When film speed doubles, the guide number changes by a factor of 1.4X; when film speed is halved, the guide number changes by a factor of 0.7X.

Based on the equation the following can be known:
-To calculate the f/stop needed, divide the guide number by the distance to the subject.
-To calculate the maximum flash range, divide the guide number by the selected or largest f/stop.

So for example, I have a guide number of 160 and a flash-subject distance of 20ft, my aperture will need to be f/8. Move the flash-subject distance to 10ft and the aperture will need to be stopped down to f/16.

Another interesting lighting fundamental is the distance to flash power relationship. This is simply: “Doubling the flash-subject distance will reduce the amount of light on the subject to a quarter of its original amount”. This is due to the inverse square relationship of distance vs. light output, but we wont get into that.

I hope this makes some sense. I will be following up on more lighting discussion as there is much to be discussed and learned.

Best,

Ivan

PS. Feel free to post your comments or own tips, techniques, fundamentals, etc. by registering here. Its quick and simple.

Which Flash Diffuser do you like best? (Hot S...

Here are some results from the Photography-on-the.net crew: click

Much of it is preference and how much room you have in your bag. Remember the bigger the light source the softer the light. Omnibounce units can only do so much, since they are limited to low, white ceilings.

Stofen Omnibounce and Vivitar 285HV Side by Side

Updates:

Stofen Omni Bounce Pros and Cons
For those who are adamant about getting a Stofen Omni Bounce should know the pros and cons:

The advantages:
-Custom fit to your flash - no velcro, no tapes, no gunk on your flashgun if you’re trying to sell it at a later date.
-Small, lightweight - you can leave it fitted to the flash when it’s sat in your bag, and have it ready for action as soon as the flash has charged up - no messing around assembling something more bulky
-Simple, effective - just pushes on and then it works.

Disadvantages:
-Custom fit: means you’ll need to buy another if you change flashgun
-Small: may not be as effective as some larger diffusers on the market
-Simple: No real flexibility beyond the angle at which you choose to bounce the flash.

Gary Fong Lightsphere Vs. Stofen Omni Bounce
posted by Nikonguy2 on Dpreview:
The Stofen and Lightsphere are but two of the many diffuser reflector adapters that are available. Both work well in limited situations. The Stofen gives good results when you have the proper surface to bounce it from but works poorly as a direct flash type diffuser. The LS works wonderfully for very close portraits and poorly in other situations as Lawrence states. My personal opinion is that the original LS that has been discontinued works better than the new ones. The Ls is not the end all product it is advertised as being and most of the samples shown on the web site appear to be high ISO and large aperture shots using more ambient light than flash.

What is fill flash?

Fill flash is often used when the subject of a photograph is in front
of a bright background, or a background with details that would
normally be lost with a standard flash mode.

Fill flash is a general term; it can mean different things to
different people, but almost always shares the common idea that it
simply bumps up the light values on the subject just enough to expose
the subject properly, without under exposing the background.

There are MANY ways that photographers achieve this. One thing to
remember is that your overall exposure should remain the same or very
close to the naturally occuring light. Your flash exposure should be
slightly lower than the ambient light (naturally occuring light). This
adds just a little bit of flash that only the trained eye can see
therefore making the photo better balanced with light and just
generally more dynamic.
dslro