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Gear Talk => EOS Bodies - For Stills => Topic started by: jdramirez on July 27, 2013, 06:30:24 PM

Title: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 06:30:24 PM
I was at a skating rink... a notoriously difficult place to shoot because it is dark and the kids are moving around faster than they can run... so you have auto focus issues, low light issues, and if you use flash, you have issues with it looking like you used flash (red eye, and the line of light that reflects off their skin and clothes).

Well yesterday I was at the rink and I was using the 5D mkiii, a 70-200mm f/2.8L IS mkii, and a 580exii speedlite.  For the pictures I'm going to show now, I was shooting at iso 2500, f2.8, and 1/1250th of a second shutter speeds. I was half bouncing light off of the rink's ceiling and half bouncing it off the built in card of the 580. 

Honestly... the results weren't that awful, but when you go into 1:1, it just looks GRAINY.  I know the mkiii is really good in low light and the grain is tolerable at iso 6400 with post production, but the attached are the raw shot before noise reduction luminance and sharpening, etc.  So I realize that a meatloaf doesn't look tasty before it is cooked... but I suppose I just would expect at 2500 less grain immediately out of the camera.  Am I just being naive and looking at the meal before it was cooked (and subsequently complaining that I'm not eating that) or maybe I should have used different settings...

Honestly, any feedback would be welcome.

(and the photos are heavily cropped to get them into the 1:1 ratio, and also because my wife doesn't like photos of my daughter existing in cyberspace... so no offense to any of yall... and I realize that the images themselves aren't very captivating, but it is the grain that I more concerned about).
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: bdunbar79 on July 27, 2013, 07:17:42 PM
So you heavily cropped them and are surprised they are grainy?
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 07:23:55 PM
So you heavily cropped them and are surprised they are grainy?

Touche'.  I was just surprised to see how much grain there is at 100%.  People constantly RAVE about full frame being the king of low light... and I don't disagree... but I feel as though the rumors would have it be so much better. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: Lnguyen1203 on July 27, 2013, 07:49:41 PM
At ISO-2500 and 100 percent crop, you will see grain.  More if the image is under exposed.  The 1DX is quite a bit better here, but you will also see grain if underexposed at same ISO.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: Ryan708 on July 27, 2013, 07:51:57 PM
Would you mind posting a non-crop, with her face and stuff removed/blurred for a better understanding? that would help a lot!
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 07:59:20 PM
Would you mind posting a non-crop, with her face and stuff removed/blurred for a better understanding? that would help a lot!

 we are watching a movie at the moment,  but I'll do just that  when it is over. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: rumorzmonger on July 27, 2013, 08:03:11 PM
Getting the right exposure will help a lot... the 5D Mark III shouldn't be this bad at ISO 2500.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: duydaniel on July 27, 2013, 08:06:56 PM
question for ya:
why you shoot human at 1/1000 sec?
human action can be stopped in general around 1/500 which give you a stop.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: bdunbar79 on July 27, 2013, 08:26:23 PM
So you heavily cropped them and are surprised they are grainy?

Touche'.  I was just surprised to see how much grain there is at 100%.  People constantly RAVE about full frame being the king of low light... and I don't disagree... but I feel as though the rumors would have it be so much better.

You're confusing then, I'm afraid, loss of detail, and grain/noise.  2500 photos I'd edit with just a 30-40% NR setting in LR and it should look find, maybe bring the exposure up a bit.  But when you crop so much you lose detail, and that's what you're doing. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: michael6liu on July 27, 2013, 08:46:12 PM
I'm not surprised if you didn't apply any NR. It is there for a reason because there will always be some noise.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 09:58:50 PM
So here are the files converted from raw to .jpg without any post production.

Again... these aren't the best of the bunch, but I just used these as examples because my subject (my daughter) is in focus.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 10:09:34 PM
And here is the other.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 10:32:54 PM
Getting the right exposure will help a lot... the 5D Mark III shouldn't be this bad at ISO 2500.

I know we should expose to the right... but I really don't think I was TOO far off... which could very well be the problem. 

I've tried long exposures at skating rinks... and that doesn't work... it blurs things out too much.  I've also tried 2nd shutter after maybe a 1/2 second and there is just to much movement that it doesn't really give me a shot that I like. 

So I did this... with high speed sync... and outside of the grain issue, I think I got the exposure of the shots I was looking for. 

Her birthday is coming up in a month and change... so if it is a consensus that I should back off the shutter speed to 1/500th and an iso of 1250... I'll definitely give that a go.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: privatebydesign on July 27, 2013, 10:34:25 PM
...... I was shooting at iso 2500, f2.8, and 1/1250th of a second shutter speeds. I was half bouncing light off of the rink's ceiling and half bouncing it off the built in card of the 580. 

Honestly, any feedback would be welcome.


Nice version:

Yep, that is a realistic output for a 2,500iso shot that dark at 100% with little to no processing. However, after you "cooked it" you should get very nice results.

Blunt answer:

1/1250 with flash that you think you are bouncing! Get real, your sync speed is 1/200, you have long since gone into HSS territory and that is an exercise in futility with one and flash trying to bounce it. You should be at 1/100-1/200, you would have around five more stops of flash power, and don't forget, your flash is the effective shutter speed in this kind of shot, you could probably shoot at 1/30 and not get trails, though trails would add an impression of movement in this case. Personally I'd be dragging the shutter, 1/15-1/40 and using second curtain sync.

Stop buying multi thousand dollar toys and start getting some online classes. I'd highly recommend this Creative Live class by Mark Wallace. Which is the best $99 you could spend on your flash photography.

http://www.creativelive.com/courses/speedlights-101-mark-wallace (http://www.creativelive.com/courses/speedlights-101-mark-wallace)

Or this Canon speedlite bible by Syl Arena. Which if you are too cheap for the videos is superb value at $30.

http://www.amazon.com/Speedliters-Handbook-Learning-Craft-Speedlites/dp/032171105X (http://www.amazon.com/Speedliters-Handbook-Learning-Craft-Speedlites/dp/032171105X)

Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: Zv on July 27, 2013, 10:46:44 PM
Couple of things - first of all at f/2.8 the dof is really shallow so the oof area will look grainy or soft. Always does. Secondly you were using ISO 2500 which is one of the in between stops that adds noise. You might have been better off using ISO 3200 and a slower shutter speed. (No need for 1/2500 as someone said, 1/500 would have been fine).

Also I assume you were using HSS on the flash so the power output would be compromised. Bouncing it off a high ceiling would just eat up more light.

I would have shot at 1/200s instead (sync speed). This way you get more control over your flash power and buys you some extra f/stops for a little more dof. The ambient light would be doing most of the heavy lifting and the flash would just be filling in.

An alternative would be to get the flash off camera and park it in a corner somehwere. It would act like a sort of extra room light. But might cast deep shadows this way without diffusion in which case a second light on camera would be useful to fill in.

A little bit of motion blur is acceptable in a shot like this, it might make a cool effect with second curtain sync.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: BozillaNZ on July 27, 2013, 10:49:18 PM
Thumb up for privatebydesign's reply. 1/1250s with flash isn't going to end up well, nor was it necessary. 1/200 is all you needed.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 27, 2013, 10:53:48 PM
...... I was shooting at iso 2500, f2.8, and 1/1250th of a second shutter speeds. I was half bouncing light off of the rink's ceiling and half bouncing it off the built in card of the 580. 

Honestly, any feedback would be welcome.


Nice version:

Yep, that is a realistic output for a 2,500iso shot that dark at 100% with little to no processing. However, after you "cooked it" you should get very nice results.

Blunt answer:

1/1250 with flash that you think you are bouncing! Get real, your sync speed is 1/200, you have long since gone into HSS territory and that is an exercise in futility with one and flash trying to bounce it. You should be at 1/100-1/200, you would have around five more stops of flash power, and don't forget, your flash is the effective shutter speed in this kind of shot, you could probably shoot at 1/30 and not get trails, though trails would add an impression of movement in this case. Personally I'd be dragging the shutter, 1/15-1/40 and using second curtain sync.

Stop buying multi thousand dollar toys and start getting some online classes. I'd highly recommend this Creative Live class by Mark Wallace. Which is the best $99 you could spend on your flash photography.

http://www.creativelive.com/courses/speedlights-101-mark-wallace (http://www.creativelive.com/courses/speedlights-101-mark-wallace)

Or this Canon speedlite bible by Syl Arena. Which if you are too cheap for the videos is superb value at $30.

http://www.amazon.com/Speedliters-Handbook-Learning-Craft-Speedlites/dp/032171105X (http://www.amazon.com/Speedliters-Handbook-Learning-Craft-Speedlites/dp/032171105X)

I understood I was doing something "wrong" and I expected to get lambasted... so I appreciate the feedback.  I would say that in the area of speedlite photography, I am definitely the weakest... however, I in a month and change when her birthday comes around, I wasn't planning on shooting with these settings. 

I plan on using off camera flash and using a better tool to bounce the light for side lit images.  Maybe it works... maybe it doesn't.  I'm a gambler in that regard...
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: rpt on July 27, 2013, 11:18:10 PM
...... I was shooting at iso 2500, f2.8, and 1/1250th of a second shutter speeds. I was half bouncing light off of the rink's ceiling and half bouncing it off the built in card of the 580. 

Honestly, any feedback would be welcome.


Nice version:

Yep, that is a realistic output for a 2,500iso shot that dark at 100% with little to no processing. However, after you "cooked it" you should get very nice results.

Blunt answer:

1/1250 with flash that you think you are bouncing! Get real, your sync speed is 1/200, you have long since gone into HSS territory and that is an exercise in futility with one and flash trying to bounce it. You should be at 1/100-1/200, you would have around five more stops of flash power, and don't forget, your flash is the effective shutter speed in this kind of shot, you could probably shoot at 1/30 and not get trails, though trails would add an impression of movement in this case. Personally I'd be dragging the shutter, 1/15-1/40 and using second curtain sync.

Stop buying multi thousand dollar toys and start getting some online classes. I'd highly recommend this Creative Live class by Mark Wallace. Which is the best $99 you could spend on your flash photography.

http://www.creativelive.com/courses/speedlights-101-mark-wallace (http://www.creativelive.com/courses/speedlights-101-mark-wallace)

Or this Canon speedlite bible by Syl Arena. Which if you are too cheap for the videos is superb value at $30.

http://www.amazon.com/Speedliters-Handbook-Learning-Craft-Speedlites/dp/032171105X (http://www.amazon.com/Speedliters-Handbook-Learning-Craft-Speedlites/dp/032171105X)

I understood I was doing something "wrong" and I expected to get lambasted... so I appreciate the feedback.  I would say that in the area of speedlite photography, I am definitely the weakest... however, I in a month and change when her birthday comes around, I wasn't planning on shooting with these settings. 

I plan on using off camera flash and using a better tool to bounce the light for side lit images.  Maybe it works... maybe it doesn't.  I'm a gambler in that regard...
Also note the comments by Zv about the ISO. If you took the shutter speed down to 1/200, your ISO could go down quite low so less noise...
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: RLPhoto on July 28, 2013, 10:43:56 PM
@ ISO 3200 on a 5D3 exposed correctly should show minimal grain. This photo was accepted by a stock agency @ full res no problemo.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 28, 2013, 11:25:19 PM
@ ISO 3200 on a 5D3 exposed correctly should show minimal grain. This photo was accepted by a stock agency @ full res no problemo.

Nice photo... but the dog is stationary with a shallow depth of field which suggests a wide open aperture which begs the question... why did you need an iso of 3200? 

And while the image can lie... it looks like it was taken outdoors during day light hours and not inside a dark skating rink. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: RLPhoto on July 28, 2013, 11:34:38 PM
@ ISO 3200 on a 5D3 exposed correctly should show minimal grain. This photo was accepted by a stock agency @ full res no problemo.

Nice photo... but the dog is stationary with a shallow depth of field which suggests a wide open aperture which begs the question... why did you need an iso of 3200? 

And while the image can lie... it looks like it was taken outdoors during day light hours and not inside a dark skating rink.

135L - 1/200th - f/2 - ISO 3200

The noise @ ISO 3200 - 6400 should be like the photo above if you nail the exposure correctly.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: adhocphotographer on July 29, 2013, 12:18:50 AM
Looks normal to me... :)
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: dslrdummy on July 29, 2013, 12:33:22 AM
 
Lovely shot RLP. Slightly tacking, did you spot focus and on the eye or the nose? Very impressed that you got both in focus with that dof.
Thanks.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: alexanderferdinand on July 29, 2013, 01:16:42 AM
Nice shot, RLP!
Less grain at high iso: exposure to the right; sometimes kind of weird color by artificial light can also cause higher grain, if you try to get a correct WB in post.
And last but not least: grain in focus looks good, out of focus kind of "spongy".
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: PVS on July 29, 2013, 11:11:39 PM
Print it in whichever size you like and tell me again that you spotted any grain in those shots.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 29, 2013, 11:16:08 PM
Print it in whichever size you like and tell me again that you spotted any grain in those shots.

Huh? 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: PVS on July 29, 2013, 11:40:20 PM
The whole point of taking photos is to view the prints.
And enjoy their artistic, technical, documentary or sentimental values.

At least it used to be like, in case things changed some please pass me the map.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: PVS on July 29, 2013, 11:43:46 PM
ps - please do try printing sometimes, you might be surprised.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 30, 2013, 12:01:42 AM
The whole point of taking photos is to view the prints.
And enjoy their artistic, technical, documentary or sentimental values.

At least it used to be like, in case things changed some please pass me the map.

I do print stills.  I don't think anything I took on Friday was wall worthy, so the really good ones go up on the wall and on facebook, and the average ones, like what I got on Friday, go up on Facebook so family members can coo and aww about how cute she is and how great of a photog I am.  Though, as evidenced by others opinion and my request for advice/suggestions, I know that to not be true. 

I try not to take offense at what people are saying when I am asking for help, but I could help but think that she was correctly exposed.  And I have take photos of football before and I found that 1/1000 of a second to be a touch slow... and I have taken photos at 1/30 and 1/60 of a second in a skating rink and I found those to be worthless... at the very least not what I was going for. 

And it is difficult to see grain in my 3 inch screen... and sharpness, and bokeh... so I go in with a game plan and sometimes it works... and sometimes it does... and then I look to see if it was something I was doing horribly wrong or whether it is simply a limitation of the gear. 

So my settings weren't ideal, but I get to do a little trial and error for the next time and I'm comfortable with doing that. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: drjlo on July 30, 2013, 01:26:03 AM
I was using the 5D mkiii, a 70-200mm f/2.8L IS mkii, and a 580exii speedlite... I was half bouncing light off of the rink's ceiling and half bouncing it off the built in card of the 580. 

I shoot with exactly the same equipment, EXCEPT I never use the built in card of 580, which is tiny.  I highly recommend large bounce cards which are cheap and really help push "half" the light forward, which the tiny card is not even close to doing.  All the other stuff about shutter speed, ISO are good advice also. 

If all fails, a good noise reduction program like Imagenomic NoiseWare Pro or Neat Image NR can save the day. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: scottkinfw on July 30, 2013, 02:36:28 AM
This is a coincidence, as I was looking for something to shoot Saturday and went to a ladies roller derby championship.  It was great fun, and I got to learn a lot.  I have never shot sports or indoors like this before.

I was shooting with my 5D3, and mostly with my 600-EX-RT flash.  I'll post some unaltered pics for you to look at, near and far.

first is iso 2000 70 mm f 3.5 1/400 from 24-70 2.8 II
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: scottkinfw on July 30, 2013, 02:38:18 AM
Here is another one, same settings, only a bit farther away.  On blowing up, grain/noise is very apparent.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: scottkinfw on July 30, 2013, 02:43:27 AM
Finally, this one is at 1600 iso and should be better on that front alone (59mm f 3.5 1/400).

Next time out, I will open up f stop more to blur out background and try to lower iso.  On cleaning up and shrinking images, results look good.

Anyway, hope this helps.

sek
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: pedro on July 30, 2013, 04:52:46 AM
Well, quite a while ago I took a picture of my (now late) cat earlier this year. Available light fingering into the dorm while it sat on the bed. ISO 51k, RAW. The animal was hardly visible, had to focus at the white parts of its ears. First photograph without NR, second with NR. Well exposed to right. Wide open.

(http://farm9.staticflickr.com/8235/8370478680_fe66168090_o.jpg) (http://www.flickr.com/photos/guatitamasluz/8370478680/)
Shooting my Cat at ISO 51k (http://www.flickr.com/photos/guatitamasluz/8370478680/#) by Peter Hauri (http://www.flickr.com/people/guatitamasluz/), on Flickr
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 30, 2013, 06:54:43 AM
I was using the 5D mkiii, a 70-200mm f/2.8L IS mkii, and a 580exii speedlite... I was half bouncing light off of the rink's ceiling and half bouncing it off the built in card of the 580. 

I shoot with exactly the same equipment, EXCEPT I never use the built in card of 580, which is tiny.  I highly recommend large bounce cards which are cheap and really help push "half" the light forward, which the tiny card is not even close to doing.  All the other stuff about shutter speed, ISO are good advice also. 

If all fails, a good noise reduction program like Imagenomic NoiseWare Pro or Neat Image NR can save the day.

I just upgraded to the 580 about a week an a half ago.  I have
http://www.amazon.com/gp/product/B003UOIMBW/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A35Z38INQ6BCGI (http://www.amazon.com/gp/product/B003UOIMBW/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A35Z38INQ6BCGI)

in my shopping cart, but I just need to pull the trigger.  I was making do.  And the ceiling I was bouncing off of was only 10 to 15 feet high and slanted towards my subject.  And this was before using lightroom.  I know how to save the photo, but I was just surprised at the amount of noise at 2500. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 30, 2013, 07:01:50 AM
Finally, this one is at 1600 iso and should be better on that front alone (59mm f 3.5 1/400).

Next time out, I will open up f stop more to blur out background and try to lower iso.  On cleaning up and shrinking images, results look good.

Anyway, hope this helps.

sek

I dont' know why I was thinking I needed to be around 1/1000 to freeze roller skating.  I guess I was doing some math in my head that a person on roller skates would be traveling faster than little kids running on the football field. 
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: privatebydesign on July 30, 2013, 08:29:19 AM

I dont' know why I was thinking I needed to be around 1/1000 to freeze roller skating.  I guess I was doing some math in my head that a person on roller skates would be traveling faster than little kids running on the football field.

Don't forget in this situation, where you have a low ambient light level and you are using flash, it is the pulse of the flash that effectively becomes your shutter speed. Think of this situation, in a totally dark room with a flash light, open the shutter with B, so it just stays open, as there is no light the shutter time becomes ineffective, it is how long you turn the flashlight on for that determines your exposure. Same thing is happening once you are killing your ambient exposure at the roller rink. In HSS, anything over 1/200, your flash will pulse for the entire exposure, it doesn't send out one burst but many little ones, once you go below 1/200 you just get the one burst and so your subject shutter speed becomes the flashes pulse duration.

To gauge exposure, meter the scene without the flash on, say it is 1/50 @ f2.8 and iso 400, once you go two or three stops under that the ambient becomes less and less effective. Set your camera to 1/200 @f2.8 and iso 400 and the flash will become the effective shutter speed for the subject, the ambient will fall a little less than two stops under exposed though the flash will bring it up, but you will have zero noise and much more dynamic range, you will also put your daughter into some context as the background will be visible but not distracting.

You don't need to buy anything for shooting where you did, the Rouge is great and I have the larger version, but with 10' ceilings you don't need it.
Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: jdramirez on July 30, 2013, 10:34:25 PM

I dont' know why I was thinking I needed to be around 1/1000 to freeze roller skating.  I guess I was doing some math in my head that a person on roller skates would be traveling faster than little kids running on the football field.

Don't forget in this situation, where you have a low ambient light level and you are using flash, it is the pulse of the flash that effectively becomes your shutter speed. Think of this situation, in a totally dark room with a flash light, open the shutter with B, so it just stays open, as there is no light the shutter time becomes ineffective, it is how long you turn the flashlight on for that determines your exposure. Same thing is happening once you are killing your ambient exposure at the roller rink. In HSS, anything over 1/200, your flash will pulse for the entire exposure, it doesn't send out one burst but many little ones, once you go below 1/200 you just get the one burst and so your subject shutter speed becomes the flashes pulse duration.

To gauge exposure, meter the scene without the flash on, say it is 1/50 @ f2.8 and iso 400, once you go two or three stops under that the ambient becomes less and less effective. Set your camera to 1/200 @f2.8 and iso 400 and the flash will become the effective shutter speed for the subject, the ambient will fall a little less than two stops under exposed though the flash will bring it up, but you will have zero noise and much more dynamic range, you will also put your daughter into some context as the background will be visible but not distracting.

You don't need to buy anything for shooting where you did, the Rouge is great and I have the larger version, but with 10' ceilings you don't need it.

We have 2 skating rinks and 4 roller skating rinks.  The one we are going to be at is going to be 30ish foot ceilings... so I'm probably going to hire one of the brothers of the girls attending for $20 and he'll hold the rouge, the 580, and a transciever... and maybe... just maybe I'll get some decent side lit shots. 

Title: Re: 5d mkiii, grain in low-light - Am I just asking for too much?
Post by: privatebydesign on August 02, 2013, 01:31:47 PM
jd,

In your situation I would start with these settings.

One 580 on camera as master (group A) with the big rouge, one 580 in assistants hand in group B zoomed to 24mm. Camera in M, flash in ETTL.

Set the camera to 1/100, f4, iso 200. Set flash to A:B 1:4, this puts group B at two stops brighter than group A and FEC at -1. Get your assistant in a position to create rim light, that is at an angle further away than your daughter and pointing at her but out of frame to your left or right.

Take a shot. If the subject is too bright adjust FEC down or visa versa, if the background is too bright raise shutter speed or again visa versa. If the rim is too bright in relation to the main adjust the A:B ratio, with Canon this means 1:1 is equal, A:B 1:2 is one part of light to A and two parts to B, B is twice as bright as A. The ETTL is taking care of different subject distances.

This should give you a good starting point and the right way to adjust to where you want.