Speedlight questions from different thread

[Tbini87]

I read through a long heated debate on using a speedlight which lead to all types of funky debates about shutter speed, iso, ambient light, etc. It got me pretty confused and I had some questions. Since most of the players from that thread were worn out from the arguing, I thought I would take a shot here in getting some basic questions answered. Any help would be appreciated!

Should I start in TTL with my SB-600 so that I don't have to try to do things manually? I am looking for the simpler, quicker, easier approach to using flash for now.

I think I generally want as much ambient lighting as possible when using flash (at least for now). So when shooting (according to some of the linked articles in the thread) it sounds like I should be using a lowest possible f-stop number (wide aperture) and bump the ISO to a higher number? This will let in more ambient light quicker right?

What is the -/+ exposure button used for? Is it dealing with the Subject or simply overall exposure of the image? Is there a way to play with that to add more ambient light? If it were for the subject it would seem that you could make that - a few stops and get a lot more ambient light in. It probably doesn't work like that since that would be too easy.

Any help in clearing up some of my questions would be great. I think these might be questions that beginners who read this thread would certainly have. Thanks.

 

[phiya]

I'm going to try to answer your questions as best I can.

TTL is pretty convenient for using your flash as a beginner. That being said, manual isn't as complicated as it seems. Lighting is complicated as there are a lot of elements to it, but trial and error can give you much of the information you need. For example, take a test shot, then adjust flash power based on the shot. Rinse and repeat until you get desired results. This can be the same with TTL, more on that later.

You are correct in saying that a lower f-stop number and higher ISO will allow for more ambient light in your photographs (flash or no flash). Also, shutter speed will effect ambient light, but generally will not effect flash exposure. Lets assume that you are only using your flash below the maximum sync speed (1/200th likely). The duration of the flash is so short that your shutter speed will not affect the exposure received from reflected flash sourced light. As a side note flash photography is usually about balancing the flash exposure with your ambient light, so you don't necessarily want maximum ambient light, depending on how and in which conditions you are using your flash.

The -/+ exposure button is used in both TTL and manual mode. In TTL it adjusts the power of the flash which is already determined by metering. Lets say for example you press - twice setting your flash to -.7 of one f-stop below TTL determined power. So your camera/flash will determine flash power depending on the reading of the light meter, and then it will reduce that power by .7 of 1 stop of light for the actual flash. You can use this to get the light how you want it on your flash-exposed subject. Take a shot, review and adjust your flash exposure compensation, or FEC (that's what it's called I believe) as needed. Rinse and repeat (see I told you it would return). In manual mode your power starts at 100%. You then use the -/+ button to adjust from there. You can tell the flash to produce 100% (1/1) or 1/128 power, and many values in between.

I hope this helps you understand better.

 

[FattyMcJ]

Should I start in TTL with my SB-600 so that I don't have to try to do things manually? I am looking for the simpler, quicker, easier approach to using flash for now.

The quickest way to learn flash is to jump in head-first. Like phiya said, trial-and-error. The easiest way is to have someone teach you in-person. IMO, read a bunch, try some, read more, try more. There is no real "easy way".

I think I generally want as much ambient lighting as possible when using flash (at least for now).

Unless you want to have white balance issues when indoors, then no...this thinking is incorrect. If outside, it's a different story.

So when shooting it sounds like I should be using a lowest possible f-stop number (wide aperture) and bump the ISO to a higher number? This will let in more ambient light quicker right?

Quick rules-of-thumb (assuming your flash power is a constant...which it shouldn't be, but that's later):
ISO- controls ambient & flash exposure.
Aperture- controls flash exposure.
Shutter Speed- controls ambient exposure (anything that's not touched by the flash)

Thus...having a wider aperture will do nothing for your ambient light, but will control your DoF. To balance the two I usually figure out what I want the DoF to be, then adjust flash power according to the aperture I'm using.

Using the ISO to control ambient is only a last-ditch effort for me. I usually use the lowest possible ISO as my "constant" so as to eliminate one of the variables from the equation that is "exposure", as well as keep the best possible IQ. If I find that I can't get the look I want using ISO 100, I bump it up until I can get the look.

What is the -/+ exposure button used for? Is it dealing with the Subject or simply overall exposure of the image? Is there a way to play with that to add more ambient light? If it were for the subject it would seem that you could make that - a few stops and get a lot more ambient light in. It probably doesn't work like that since that would be too easy.

Again, see "Ambient is controlled by shutter speed & ISO". The EV comp button is used to the same end as adjusting your aperture & shutter speed manually, but you let the camera decide for you. That's cool, if you trust the camera. I don't.

Any help in clearing up some of my questions would be great. I think these might be questions that beginners who read this thread would certainly have. Thanks.

One of the best FREE resources on the web for learning flash photography is Strobist: Lighting 101 . Start there, read and try things, then come back and ask questions for particular situations.

Good luck :thumbup:

 

[Blake.Oney]

This should answer a lot of your questions.

 

[Tbini87]

Thanks guys. I have actually been doing a lot of reading on Strobist which has opened my eyes a ton to flash photography. There is so much confusing language when discussing flash (and photography in general) and that site really lays it out fairly simply. We have some wireless triggers on the way, and we plan on doing a ton of practice in the near future. Hopefully getting out there and working with the flash will really bring these concepts to life. Thanks for the help and links.