Indoor Flash - ISO and Shutter Speed Question

Hi again.

Back in July someone started a thread about what custom settings do people use. I was very interested in the indoor flash settings so I decided to try out some of the suggestions.

I used the camera's onboard flash and after various test shots my wife and I concluded that the following P850 Custom settings worked best overall (the bedroom shot with the curio cabinet presented the biggest challenge).

Now for my question. In simple terms can someone explain the relationship or interaction of ISO (in this case 100) to Shutter Speed (here 1/80).

Regards, John....

Af Control SINGLE
Az Zone CENTER ZONE (multi looked overall out of focus)
Exposure Metering MULTI PATTERNED
Exposure Compensation 0.0
Flash Compensation 0.0
Sharpness and Contrast NORMAL
Flash Set-up SLOW FRONT SYNC
ISO 100
Shutter Speed 1/80

Very simple. You put your ISO to 200 and your shutter speed will be 1/160 (if all other parameters are same). You put your ISO to 50, then shutter speed is going to 1/40.

If you increase ISO twice, you can use twice quicker shutter speed (with same lightning conditions, if you doesn't change exposure compensation or aperture) and opposite, if you decrease ISO twice you must use two times slower shutter speed.

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P850 + OLY 1.7 TCon, CX7430

MuumiTroll said:

Very simple. You put your ISO to 200 and your shutter speed will be
1/160 (if all other parameters are same). You put your ISO to 50,
then shutter speed is going to 1/40.

Click to expand...

MuumiTroll

In my case I locked the ISO at 100 and I locked shutter speed at 1/80. If I understand what you are saying, if I simply locked ISO at 100 then the camera would use a shutter speed of 1/80 by default (all other things being equal).

As a follow-up question, for indoor flash under "normal lighting conditions" is ISO 100 the best and why?

John...

If you use some mode (for ISO and shutter) which calculate them, then yes, if you lock one, another is depends on it. In Manual mode and Shutter mode for example you can put it as you want.

Why 100 is best ??? I think, its not important at all, is it 100 or something else. It depends from light, from aperture as well. ISO 100 is actually good choise, because its not noisy (as 200 is, 160 is something between), in same time it allows you use quicker shutter speeds (less shake).

Same pictures doesn't work in night when you have not any additional light from window. On cloudy day you may discover something else.

I say a little remark : you watch too much these parameters, I mean as numbers ... Just watch more to screen, you like or not picture and if not change some parameters to + or - (but no need to know must be it 100 or 80). Its just my remark, I am mysef mathematic and love numbers, but in other hands I like basic relationships more.

--
P850 + OLY 1.7 TCon, CX7430

MuumiTroll said:

I say a little remark : you watch too much these parameters, I mean
as numbers ... Just watch more to screen, you like or not picture
and if not change some parameters to + or - (but no need to know
must be it 100 or 80). Its just my remark, I am mysef mathematic
and love numbers, but in other hands I like basic relationships
more.

--
P850 + OLY 1.7 TCon, CX7430

Click to expand...

MuumiTroll

I am not sure if this term may be understood outside of the U.S., but I agree that I am "anal" in that I delve into a lot of details. For me, using a specific example and trying to grasp the details helps me to understand the realtionships.

The outdoor photos that I have posted so far helped me understand Focal Zone, Exposure Metering, Exposure Comensation, and Aperture Priority in some detail which helped me understand the relationships.

Now that I am doing some indoor flash shots I guess I am struggling with the details in order to understand the relationship of settings that have the biggest impact on indoor flash photo quality.

THANKS for the great feedback.

Regards, John...

Those are great pictures, but I agree with Mummitroll, don't get hung up with numbers. Each picture is going to be different, so just experiment with the different settings, and take multiple shots to find the right ones for that particular scene. You might try taking those shots in Auto mode and see what the camera selects so you would have a reference point.

--
Chris
P850

http://photobucket.com/albums/a157/pcchris01/Favorites/

I hope I didn't say something too deep ... In case I say, that sometimes knowing exact numbers may be good. If you read some posts you may discover also numbers there (aperture, shutter, ISO, etc ...). Usually more professional person dont need to know these exact numbers, but he may get useful information (realtionships about these numbers). I look these numbers more like : this 1/80 isnt important, but this 1/80 tells me, that shutter is something between 1/50 - 1/150 and this is important. So, ISO is 100, I need to know, that ISO is between 80 - 160 or so. Ah, apeture 5.6, it tells me, that aperture is middle one (no need to know, is it 4.5 or 6.0 because they are similar). If somebody tells, shutter is 1/10, then its interesting, because shutters 1/2 - 1/30 are very slow from hand for example ; if shutter is over 1/200 - 1/300, then no moving blur expected and so on.

But work you do is interesting. Because you may discover something important. I've myself also done tests and studied parameters. Just I mean, if you go capture somewhere, then important is that these numbers dont confuse you, Its bad when you in important moment start think about numbers, picture and composition are far more important itself.

As I sayed I study math. In math also, if you study too much exact things, you may lose your head. More simple is to understand basics and meanings and relationships (ofcourse there are also things like facts, year numbers in history and so on ... these are exact things and need just boring learning).

Ok, but you keep it going. Its interesting to know, because somebody must do that :--) if others don't do :--) As this Landscape F-numbers question, I actually didn't know this problem, that there not much different...

And one thing more : as you searched good settings for indoor shots. Actually you need to get right exposed pictures (as you got last time, they pretty good ones). All you must know, how to expose you pictures (but you already know, that Exposure Compensation is the weapon, but also this fact, that if you change Exposure, then something else also may need to change as ISO or shutter and in some cases some parameters values may be not good as low shutter speed according shake and high ISO according noise) But you already know, that Exposure Compensation isn't only weapon ... and so on.

--
P850 + OLY 1.7 TCon, CX7430

JP,

I think the ISO 100 recommendation with a shutter speed of between 1/60 and 1/80 is a good compromise between image quality and shutter speed. I think that 1/60 is also a common setting for flash photography from the film days. Within the stated range of your on-board flash, this will probably give you the best indoor/night time photographs. I saw this tip when I was still using my DC4800, and it worked very well, both with internal and external flashes.

That said, if you were to use a more powerful external flash, you might find you can extend your range for acceptable pictures by increasing the ISO to 200 (since you're effectively making the image sensor twice as sensitive to light). The only other alternative would be to drop the shutter speed, which would almost certainly introduce ghosting due to movement in the camera or the subject.

With my P20 flash attached, I keep one custom setting for ISO 100, 1/80, flash EV +1 for normal indoor shots. I have another that is ISO 200, 1/60, flash EV +1 for shooting at our church. We have a large room and I frequently need to shoot at 20-30 feet from the subject. The lighting is OK to see by, but a nightmare in which to photograph.

Just remember that the relationship between ISO, shutter speed and aperature are a balancing act. If you increase ISO, you can decrease either aperature or shutter speed, but not both. If you need a faster shutter speed, you either increase ISO or open the aperature, but not both. Keep experimenting. I know I've shot thousands of picture to try and get this right--and I'm still learning!

Hope this helps.

DJMusic said:

Hope this helps.

Click to expand...

DjMusic

Yes it helps very much.

I may not have made myself clear with my first post. The reason I looked at the custom settings that people used for indoor flash photos was to establish a starting point for my trial and error shots. Most if not all of the custom indoor flash suggestions that I gleamed from this site used a ISO setting of 100 for normal lighting conditions. So I figured I might as well use this as a starting point for my playing around with other settings.

As a side but related topic, as my wife and I were reviewing my test indoor flash photos to see which ones we liked the best we were frustrated with the lack of focal clarity (overall photo just looked somewhat fuzzy or out of focus) on my first shots in which I used AF Zone Multi Zone, the same as I used for most of my outdoor shots. I got to thinking that AF Zone should not make any difference whether I am using a flash or not. So I said to myself, what setting can I change that may make the focus look better to us. I tried AF Zone Center Zone and low and behold the new photos passed the most imporant test - my wife liked them. I concluded that Multi Zone was OK for outdoors since there is not a lot of detail in the picture. By using Center Zone the objects in the center of the picture, and all objects that were in the same field depth as the center object, were clear.

Thanks to everyone for taking the time to provide input.

Regards, John....

Wow i see someone collects dolls.........is there any chance of seeing some of those dollys up close please.......i know a couple of girls on here collect them,

Jen

littleeagle5 said:

Wow i see someone collects dolls.........is there any chance of
seeing some of those dollys up close please.......i know a couple
of girls on here collect them,

Jen

Click to expand...

Jen

The dolls and curio cabinet (that's what I call it) came from my wife's mother who passed away a couple of years ago. My wife set this display up in our guest bedroom in order to keep her mother's memories alive.

You request for more photos has me energized. This will give me an opportunity to play around with indoor flash photos. Thanks for asking!

Regards, John....

Interesting discussion!

Isn't the shutter speed a bit different when using flash? Since the flash only lights up for something like 1/1000th sec. or less, the shutter being open longer only helps if there is ambient light you want to capture. A good example of this is your pic with the window in the picture. Here you have nicely exposed the scene outside the window, and used the flash to light up the dark interior, so your shutter speed is appropriate. If you were in a room with no windows, or at night, you could probably use a much faster shutter.

What's that old saying? Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. Now you have no doubt!

--
Jeff

That is correct.

For Electronic Flash, the flash light bursts out at typically 1/1000th of a second. If shoot in the relative darkness, shutter speed has no impact on the photo, because the flash is the primary and only power source.

Flash exposure is measured as a Guide Number. The GN is benchmarked at ISO 100 and the maths involves f/stop and distance from the flash. Shutter Speed is not a factor. If you want to experiment, set the PASM to M, find a large, dark room or outdoors. Note the the benchmark is to compare the light output of the flash unit - you don't have to set ISO 100, you can set any ISO you want.

Now, that is Flash as the only light and assuming no reflecting surfaces.

"Real life" photos indoors are not like that - there is the factor of ambient light (light from the room lamps, light from windows and so on. This is called Mixed Light photography. In this case there are two competing sources of light:

a. ambient light - where the normal exposure calculations hold - f/stop vs shutter speed vs ISO

b. flash light - where the exposure is f/stop vs ISO vs distance from the flash.

The two equations overlap on ISO and f/stop.

When you are still learning the effects of a. vs b. vs aggregate, you can

1. Set the camera to M. Then shoot at 1/1000th of a second with flash, changing your f/stop. Keep the ISO at 100

2. Set the camera to M. Switch off flash. Use the range of f/stops that you tried in 1 and try a bracket of shutter speeds. Keep the ISO at 100

Having seen the results of 1 and 2, you will now have a gallery of shots where the parameters overlap. Then you try

3. Flash on. A mix of shutter speeds and f/stops. At ISO 100.

Finally

4. Flash on. PASM on P. Let the camera decide. At ISO 100. Then compare the gallery of 3 vs the shots in 4.

Focussing is a separate topic. Indoors you have:

a. objects close together hence deep DOF is usually preferred. And the autofocus may "grab" at the wrong object.

b. near distances - less than 12 ft typically hence deep DOF is usually preferred.

c. poor contrast for the autofocus mechanism.

d. camera handshake

e. large opening in the f/stop (remember the smaller the f/stop means the larger the opening)

The combination can cause blurred photos.

--
Ancora Imparo - abbiamo tutti qualcosa da imparare
http://www.flickr.com/photos/32554587@N00/

Actually,

"Flash output is measured as GN", not "Flash Exposure"
--
Ancora Imparo - abbiamo tutti qualcosa da imparare
http://www.flickr.com/photos/32554587@N00/

littleeagle5 said:

Wow i see someone collects dolls.........is there any chance of
seeing some of those dollys up close please.......i know a couple
of girls on here collect them,

Jen

Click to expand...

Jen, as requested.

Very difficult lighting conditions..... Outside was dawn and no sunlight (around 7:30am my time). Ambient light was from 2 lamps with dark shades. Dolls were in dark corner in curio cabinet or on a chair. Played with Macro and Wide and I was frequently challenged to get a focus lock.

Thanks again for asking for these.

I learned that my wife played with these dolls as a child.

Regards, John...

Oo, you master your camera pretty well already. Beautiful dolls. Maybe you should post new thread, because somebody may lost this post.

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P850 + OLY 1.7 TCon, CX7430

DJMusic

Since you have a P20 flash attachment do you use it all of the time regardless of the subject's distance, or do you use it only when you are beyond the onboard camera's flash range?

Thanks in advance.

John....

I use it almost all the time. There are exceptions, like when I don't want the bulk, but the P20 does a great job. I use a number of diffusers as well, and it's difficult to do that with the onboard flash. There are times I use both the onboard and P20. The camera will compensate and not over-expose the image. If it's fairly dark and you wish to use a bounce flash to lighten the background, this combo works well.

One note. The P20 has falloff in the corners if you're shooting less than about 50mm. From what I've read this is fairly common for external flashes and wide camera angles. A diffuser will take care of this quite nicely and give you some great pictures.

Thank you very much!

John...