Hot Shoe Diaries - DPChallenge Forums

03/11/2011 10:37:36 AM · #126

Ok -- it's been way too long, and I haven't made much progress on understanding flash. So I've started in again. I'm reading the Speedlighter's Handbook, and I'm going to start journaling what I'm learning again.

The reasons were:

1. To help others who are in the same boat.
2. So that the experts can correct me when I'm wrong and misunderstanding something.

Nikon AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6G VR

03/11/2011 10:40:44 AM · #127

3/11

Dear diary -- trying flash again.

First thing I'm trying out is one of the first "key sayings" in the book:

"Aperture controls flash exposure. Shutter speed controls ambient light exposure."

I'm not starting out in manual, I'm starting in Av, and shooting a flash from the left hand side of the picture. Flash is set to 1/16th power.

This is what I've found: The wider the aperture (and faster shutter speed), the more the flash controls the light. The narrower the aperture and slower shutter speed, the more the ambient light controls the shot.

Examples:

1/40 @ 2.8

1/20 @ 3.5

1/13 @ 4.5

1/8 @ 5.6

1/5 @ 7.1

.3 @ 9

.5 @ 11

.8 @ 14

Message edited by author 2011-03-11 10:48:51.

RainMotorsports

Nikon D60

03/11/2011 10:51:29 AM · #128

Wendy i cant believe i did not see this thread before. I have the hot shoe diaries as well but not the speedlight hand book. Pretty much everything i have been working on involves my hotshoe sigma on and off camera. Ill see if I can write down what I have learned at this point.

alohadave

Pentax K-5

Pentax DA 16-45mm f/4.0 ED AL AF

03/11/2011 02:35:28 PM · #129

Originally posted by vawendy:

3/11
I'm not starting out in manual, I'm starting in Av, and shooting a flash from the left hand side of the picture. Flash is set to 1/16th power.

This is what I've found: The wider the aperture (and faster shutter speed), the more the flash controls the light. The narrower the aperture and slower shutter speed, the more the ambient light controls the shot.

Get into manual and redo your test. The reason that you are seeing the results you are is because the shutter speed is changing as you change the aperture.

Aperture affects flash and ambient
Shutter speed affects ambient
ISO affects flash and ambient
Flash power controls flash
Flash-to-subject distance affects flash

It really helps if you think of it as two separate exposures that happen at the same time. The ambient exposure and the flash exposure.

Go through this exercise and it should help: //strobist.blogspot.com/2007/09/lighting-102-33-balancing-flashambient.html The flash exposure and aperture didn't change through the series, but the shutter speed did.

03/11/2011 03:29:55 PM · #130

Originally posted by alohadave:

Originally posted by vawendy:
3/11
I'm not starting out in manual, I'm starting in Av, and shooting a flash from the left hand side of the picture. Flash is set to 1/16th power.

This is what I've found: The wider the aperture (and faster shutter speed), the more the flash controls the light. The narrower the aperture and slower shutter speed, the more the ambient light controls the shot.

Get into manual and redo your test. The reason that you are seeing the results you are is because the shutter speed is changing as you change the aperture.

Aperture affects flash and ambient
Shutter speed affects ambient
ISO affects flash and ambient
Flash power controls flash
Flash-to-subject distance affects flash

It really helps if you think of it as two separate exposures that happen at the same time. The ambient exposure and the flash exposure.

Go through this exercise and it should help: //strobist.blogspot.com/2007/09/lighting-102-33-balancing-flashambient.html The flash exposure and aperture didn't change through the series, but the shutter speed did.

Thanks so much! Before I even saw this, I decided to play with manual just to see what happens.

IT IS SO COOL!!!!

Finally, I was able to do a half black half lit picture! In the daytime! I'm so excited!

Your explanation and the link were very helpful explaining what I stumbled across. It's one thing to experiment and discover. It's another to understand what you've discovered. And your post was very helpful for the understanding process.

I'm going to go experiment some more and post the results. :D

Nikon AF-S DX Nikkor 35mm f/1.8G

03/11/2011 04:14:57 PM · #131

ok -- here's switched to manual, adjusting the shutter speed all set at f22:

1/40

1/15

1/10

1/6

1/4

vikas

Apple iPhone 13

03/11/2011 04:27:24 PM · #132

This is good exercise - its good to see the results!

Same results can be achieved by keeping the shutter speed constant and varying the aperture.

- Keep shutter speed at sync speed (1/200 or whatever is fastest for your camera)
- Set the flash power/distance to expose the bear properly
- Vary the aperture and you will see the same variation in ambient and DOF (if that's what you are looking for).

dianapf1

Canon EOS-7D

Canon EF 70-200mm f/4.0L IS USM

03/11/2011 05:40:07 PM · #133

Wendy,
I will follow your diaries and hopefully I can learn something from them. I am tired of my flash living on my camera as though it barely exist. Do you like the Speedlighter's Handbook?