Monday, February 21, 2011

Getting to Know Your Own Modifiers


Preamble....

For a small number of you, this post might be very insightful and you may even feel so motivated to carry out the same experiment. For the vast majority though...I realize it might be a bit of a slog, so don't worry...I completely understand - but be sure to tune in next week when we get into making great, crisp images of fresh strawberries splashing into a wine glass full of water and freezing the action at high speed.

Since I first got my first umbrella some 6 months ago and my second umbrella, softbox and reflector set a couple months ago I've been meaning to get to know them a little better. What's the difference in light quality, what's the difference in catch light, how much light am I losing/gaining using one vs. the other¿?

I finally decided it was time to find out. I did a whole pile of test, which were by no means completely comprehensive or overly scientific, but I did manage to find the answers to some of my own questions and feel better equipped to handle different situations as a result.

Thanks to Cristy for being patient enough to sit there the whole time. I know her glass looks very close to empty in some of these shots - just for the record...a refill was offered but declined.... So not to worry - when YOU come to model for me, you're sure to get at least a couple glasses of wine out of the deal too!

After some quick research online, it turns out I'm not the only one with the idea, of course - Zach Arias (or "Zach One Light" - the guy is amazing!) has offered up this Modifier Rundown where you can see much more on umbrellas, softboxes, octabanks, striplights, gridspots, etc. I just plain don't have all those great toys (yet), but I thought I'd share a few results for other geeks with similar gear on the outset of their creative lighting endeavours.

There's no shortage of different ways to make someone look terrible and in my series of tests, I definitely came across a few - I think it's important though to take the time just to see what different things look like  for comparison. I also think it's a good idea to put your best work online and save the less-good stuff for home study. And to that end, there is only a small part of our experiment posted so as not to bore anyone too terribly or post terrible pictures....

Setting

Everything was shot with a Canon 50mm 1.4 prime with Cristy 3 feet in front of a dark background 4 or so feet from an off-white/cream wall to her right (yes...we have a relatively small living room...). One thing to note is that the cheap inexpensive Westcott kit stands don't allow the speedlight to point into the centre of your umbrella, so...your light will always sit a little high.

All images have been treated with bare minimum processing. Since they were shot in RAW format, they did need some mild sharpening, etc.

If you decide to do the same thing with your own gear, yes you can rely on the EXIF info later, but...that won't tell you how your speedlight was zoomed, where it was in relation to your brolly, how far it was from your subject, etc. so grab some note paper (lots) and a pen and get ready to write it all down. The picture taking took some hours, but studying the images with the notes and compiling the results after has taken me a few days, so get ready to learn a ton should you opt to assign yourself the same task.

I must admit, since I'd already read Lighting 101 over at Strobist.com with David Hobby some time ago, I was initially a little confused as to why the shadows seemed to actually get softer when the apparent light size was becoming smaller as I moved it further back. Then it occurred to me: the off-white/cream wall about 4 ft. from Cristy's right was filling in the shadows and lighting more of the environment (including the background) because of the light's own depth of field.

Before we jump in...if you don't make it all the way to the end of the geekery here in this post, I'll totally understand and promise not to get offended, but just be sure to fast-forward to the very end for the outtakes.

Onward - One light:

The first series of tests was carried out with just one speedlight (Nikon SB-24/Canon 580 EX - triggered with Alien Bees Paul Buff CyberSync radio triggers) and one Photoflex 45" convertible umbrella (used both as a reflective and shoot-through) with the shutter set to highest sync speed at 1/250 sec.

Some say you should always mount your umbrella far back to avoid hotspots, others use their umbrella choked up intentionally to make their light source smaller and create more contrast. We tried it all - flash zoomed in, out, placed way far back from the umbrella, in nice 'n close. Try it and compare the images later on to see the effect on your subject so you have a clearer idea of what looks good to you. Then try out different distances from your subject - compensating for lost/gained light, of course - and see how you control the lighting just on the subject or use it to light the whole environment (click any image to see larger version):

Nikon SB-24 at ¼ power zoomed to 50mm, 20" from umbrella:

taken to find out how evenly (or unevenly) my umbrella is being lit
shoot-through                          reflective                             bare flash


gradation between light & shadow
and check out those goose bumps - was it really that cold¿?
Two Lights +Reflector (softbox/umbrella/partially collapsed umbrella):

Canon 580 EX used as backlight, SB-24 used as key light, 5-in-1 reflector kit used as indicated - white reflector only.

Photoflex 45" shoot-through umbrella 45° to model camera right:

f/8, ISO 400 with reflector camera left for fill, backlit with Canon 580 EX
same as above without backlight
same as above without reflector
same as above with reflector pointed up (resting on her lap)
Umbrella higher up and closer without reflector - ISO 200
with backlight brighter by 1 stop (damn check out those triceps and shoulders!)
same as above with reflector pointed up (resting on her lap)
Reflective umbrella partially collapsed - quite a contrast:

without reflector
same as above with reflector camera left
same as above with reflector pointed up (resting on her lap) 
f/5.6 collapsed umbrella slightly higher and closer to model
very dramatic look - perhaps better for a dude
same as above with reflector pointed up (resting on her lap)
Westcott Apollo Softbox kit (28") - approx. 2 feet away - less than 45° to model:

no backlight, no reflector 
same as above with backlight
same as above with reflector camera left
softbox from above/slightly further camera right
same as above without reflector (more shadow camera left)
f/5.6, ISO 200 - otherwise same as above (background is clearer)
f/8, ISO 400 - otherwise same as above (background even clearer)
45" Photoflex umbrella (shoot-through) for direct comparison at same position ½ stop brighter than softbox:
without backlight/still without reflector
the bigger light source makes the light softer
with backlight
these last 2 images resemble the softbox in closer with reflector - see above
Open to comments, critiques and/or corrections.

For a cool video on using one light as both your main and background light, check out this cool video with lighting master Tony Corbell and listen toan interview with him (and many others) here on Nik Radio (2/17/11 release).

Conclusions:

I compared the output of my Canon 580 EX and SB-24 - interestingly Canon rates its Guide Number at 190 (138 zoomed to 50mm) while Nikon rates its GN at 164 (138 zoomed to 50mm), but the Nikon appears to be almost ⅓ stops brighter. My flash gun from the late 80's is actually more powerful¿?

You can see from the tryptic under the "one light" section that the light is softer using a shoot-through in comparison to a reflective umbrella. The trade off is that you lose light (about  stop). This means if you need more light, using a reflective umbrella is the more efficient alternative, but...you can't bring it in quite as close.

I'd seen/heard of people using a partially collapsed umbrella (reflective) to direct the light and control the spill feathering the light more like a softbox. I found that to be very contrasty and might be a dramatic effect well suited to a guy - not so much a glamorous look....

I also wanted to see if there was any difference (besides 2") between the Photoflex and Westcott convertible umbrellas - turns out there was a very small difference noticeable when the images are side by side, but as you might expect, the difference is pretty negligible. For the record it looked like the Westcott is perhaps slightly cooler.

A softbox eats up a lot of light. Since it's only something like 28" it's a little more contrasty than my umbrellas - time to save up for a bigger one.

Outtakes:
this...is...awesome...!



Still here¿? You made it! Thanks for reading....

Oops! Have I missed something?! Help share resources by adding them with a short description in the comments section or write me and I'll make sure it gets posted!



3 comments:

ardean said...

you went all out! gotta come back and read when i have more time!

shayne gray learns photography %$#! said...

You bet - and this is the reduced version...!

William Self said...

Great post Shayne. Makes me want to run out and buy a whole whack of lighting equipment.

I'm really partial to the results you got from the "poor man's soft box". Nice contrast in that set. Nice to see one does not have to spend a fortune to get great looking results.

Keep these coming!

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