Understanding Exposure

[kgphoto]

Originally Posted by expensive_hobby

Hmm... I do hope the rest of this was not directed at me. I've clearly *defined* myself in my signature.

Absolutely not directed only at you, it was directed at the generic or Imperial you(meaning everyone equally). NO offense meant. Just a slight kick in the pants to all.

[harryd]

However, I think that much of this is going over the heads of some of the readers here.
And I also think that too much information is being dumped on people that really just need to understand a few simple concepts before delving deeper into the more complicated things. You don't teach algebra to students that are still trying to grasp multiplication.

That would be me! Dean thanks, printed out your post and will be playing soon!

[kgphoto]

Originally Posted by KellyL

Oh boy....one day away and I have a lot of catching up to do.

These shots that I take of the kids at band camp are while they are practicing on the field. They are not staged shots. I get what I can get as they march around. I have to do the best I can. I do not get to pick the day, the time of day, or the location. I will be following them all season and taking pictures. Our weather here right now is not good. It is muggy. The sky is gray. The humidity can be seen in the air. All of these atmospheric elements are effecting the picture quality. These are not excuses...just what I have to deal with.

My solution was to attempt to use an on camera flash. I can't find a diffuser for the Metz that will allow for soft lighting, so I have purchased some material to attempt to make a diffuser. The shots here have no flash.

Kelly,

Think of band camp shots as wedding shots. This is one of the reasons I chose the Norman 200B as my flash. Its reflector is 5 inches in diameter which makes it softer than most other flashes, right out of the box. It also throws a very even spread of light due to its design. Adding a soft box or other diffuser system makes it even mo' better!

When my daughter was born, I was in the delivery room with a Hasselblad and a 200B with a 12x12(inch) softbox on it. Talk about no staged shots and having to get what I can get while it is happening. Before you say this is too hard and complicated, remember this is an all manual system and I had the nurse "snap" the shot of me cutting the umbilical cord. So even a beginner can do it.

I thought there were several diffusers available to fit the Metz? In fact, I thought most fit. This is not to say that most or many are good, but they fit.

If you are going to use auto settings on your flash, make sure your diffuser doesn't block or shine into the sensor. That is one of the cool things about the Vivitar 283. It has a cable that allows you to mount your sensor up to three feet away from the flash head, so you can use a soft box set on AUTO!

Of course on manual, this is not an issue.

I must re-emphasize what Brooks said. Definitely study the Zone System as most can be applied to digital photography.

The way to avoid contradictory advice is just to go to the basic science and groundwork of these systems. Then you will be able to separate the hype and opinion from the reality. This is what Brooks and I have been talking about. The rest is interpretative short cuts and you know how I feel about those!

By the way, I made a mistake. While I still recommend reading the entire series of Ansel Adams' books, The Camera, The Negative and The Print, it was the book "Photography" by Upton and Upton that offered the best synopsis of the zone system with the pictures and arrows and gray scales. I had that book for a collage photography course and was reading the others at the same time, so I combined them in my mind.

With all dues respect to Dean, While I agree that learning to read a histogram is a good thing, I would still recommend getting hand held light meter that meters both flash and ambient and some degree of spot capability and learn to read exposure and take notes. A meter like this can be had for about $200. If you take off flash reading, you can get one for about $100 and if you take off spot reading and are willing to do the walking to meter, even less.

Even if you just set your camera to spot reading and use it as the meter, I would do that first. Just make sure you write down the numbers so you can compare them later. Pick 5 parts of the scene, meter, note and shoot. Then later see what came of it. This is more direct, less interpretive than trying to read a histogram. It does take the discipline to write the notes though. No Shortcuts!

[KellyL]

I will continue to thank everybody for their continued participation in this thread. Very grateful indeed. The patience that has been exhibited creates a wonderful model for everybody, and encourages those of us who are the learners here to have the same patience when we have the opportunity to share with others. Your kindness is not going unnoticed.

Brooks...I do thank you for lettimg me see that I understand what you wrote. When I first read about the N's and the N- and the N+ I will admint I was swimming just a bit, if not dog paddling. I have a greater understanding of what you have been trying to say.

Pensive: Keep at it. Keep posting. One day we will feel like we have a greater understanding and a firmer grasp on exposure.

Padre: So grateful you stopped by and gave a real world example of what we are grappling with. You managed to keep the detail in the dress, the background, the tux, and the skin tones. Congratulations.

Dean Johnson: You are right about not getting too lost in all the discussion. So much has been shared, but when the nitty hits the gritty and you must take some drive by shootings, you must lean on what you understand and push to add a little more.

Here is an image I shot last night at band camp. In this situation, I do not have time to adjust settings, I have to rely on aperture priority. But knowing where to take a reading in such rapid fire settings helped tremendously. I am very pleased with these exposures from last night. The subjects were backlit, so I shot at an angle, using the sun more as a sidelight. I was thrilled that I was getting rim lights on most of my shots. Happy that I knew not to shoot so the sun was directly behind them, and content to know that when I was metering the skin on their faces I was taking about a 36% reading. If I would have knocked my EV up 2/3 stop, I think I would have even been more grateful. I used center weighted metering...I think...Brice will correct me if I am wrong! I don't see that information displayed in lightroom.

Regardless, because of this discussion, I have gotten better...my understanding has increased and I feel more confident with what I am doing on the field.

[JohnC]

I'll add another vote for the Upton "Photography" book (actually Barbara London and Jack Upton). If you buy the latest version (7th Edition) it is $100 or more. But I regurlarly see 5th Edition or earlier books in used book stores for around $5 to $10. Come to think of it, I don't think I've ever seen a 6th Edition version.

[kgphoto]

Kelly,

To me, the girl and guy with the flute are the subject of the picture. They look underexposed or "muddy" as pictured here. I would have put the sun more behind them and opened up more. Failing the ability to do that, I would have hit them with more flash and stopped down.

I pre-meter many sites. Then I pre-set the camera, then I can concentrate on capturing the expressions and antics. Light doesn't change all that rapidly most of the time.

[JohnC]

One more (hopefully clarifying) thing. We really shouldn't refer to setting the aperture between 8 and 11 as 8.5. If we're writing about 1/3 stops it would be 9 or 10. If we're writing about 1/2 stops it would be 9.5.

In casual conversation it works to say "between F/8 and 11." And you might get away with calling it 8.5 in conversation. But written down we should be more clear.

For reference, here is the 1/3 stop scale (at least according to Canon)...

2.8 / 3.2 / 3.5 / 4 / 4.5 / 5 / 5.6 / 6.3 / 7.1 / 8 / 9 / 10 / 11 / 13 / 14 / 16 / 18 / 20 / 22

1/2 stop scale...

2.8 / 3.5 / 4 / 4.5 / 5.6 / 6.7 / 8 / 9.5 / 11 / 13 / 16 /19 / 22

[KellyL]

Kirk, what I failed to do is open up 2/3 on EV which I should have done.

Here is the question of the day, which is why I did not use a flash last night. When I turn my flash on, my shutter is limited to 1/250. I suppose I could have metered the background (?) prior to taking the pictures and set my flash accordingly (?). I don't have a diffuser for my Metz, and if I had used my Canon 580EX, I would have equipped it with the Fong Diffuser. I was also using the 70 - 200 on these shots which put me at quite a distance from the subjects.

[KellyL]

According to Amazon, I was able to purchase the 7th edition for 10 bucks, used. (the Phtography book).

[expensive_hobby]

Originally Posted by Dean Johnson

I don't have lots of time right now but I wanted to chime in....

I think this is a great thread....LOTS of good information here.

However, I think that much of this is going over the heads of some of the readers here.
And I also think that too much information is being dumped on people that really just need to understand a few simple concepts before delving deeper into the more complicated things. You don't teach algebra to students that are still trying to grasp multiplication.

That statement is just screaming my name! Thank you for taking the time to post in this thread, and especially for taking the time offer constructive ways of learning.

Don't worry harryd... I'm right there with you!

[Brooks]

Originally Posted by JohnC

One more (hopefully clarifying) thing. We really shouldn't refer to setting the aperture between 8 and 11 as 8.5. If we're writing about 1/3 stops it would be 9 or 10. If we're writing about 1/2 stops it would be 9.5

John, you're right. For literally decades I've always thought of the half stop between f8 and f11 as f8.5 or f8 and 1/2. It wasn't until I started shooting digitally that I learned of f9.5. F9.5 just seems so strange to me. This digital stuff is the devils work!

[KellyL]

Brooks, the number system can be very confusing to me. I looked the charts up on Wikipedia before I commented earlier because I wasn't sure where 8.5 fell. It seems odd to me that if a full stop doubles light then the numbers should be consitently doubled. But its okay....I'm okay.

[JohnC]

The f/stop progression is based on the square root of 2 (1.44). 2.8x1.4 = 4, 4 x 1.44 = 5.6 (there is a lot of rounding off involved, if you try this on a calculator the numbers won't match up completely).

What used to drive me really crazy years ago was the Minolota Flash Meter III. It measured in 1/10 stop increments. I know people who would go mad trying to adjust multiple lights in a scene to match up and wouldn't accept a 1/10 difference. I have no idea where they thought they were going to be able to see that difference.

[JohnC]

OK, on to fill flash. You are limited by the sync speed of your shutter to the flash. On cropped cameras this is usually around 1/250 of a second. On fullframe cameras it might only be 1/125 of a second. This is the shortest shutter speed you can use and still have the flash cover the entire frame. With faster shutter speeds the shutter curtain will start closing before the flash is recorded and you will get dark bands across the wide length of the frame. The Strobist has an example image on Flickr at ShutterSyncTest on Flickr - Photo Sharing!

Normally, you can set your shutter to slower speeds. But there is a custom function in Canon cameras to force the shutter speed to the top sync speed. So if you cannot select a different speed than 1/250 check you CFs.

Recently wrote a blog entry on outdoor fill flash at It Figures: Outdoor Fill Flash

[brice]

Originally Posted by KellyL

Brice will correct me if I am wrong!

Are you testing me?

What I see is "pattern" for metering mode. Sorry Kelly... Either my EXIF view is defective or somethings wrong in your setup. I wouldn't have mentioned if you didn't test me.

What it does point out is we've all got to keep an eye on our settings (there are so many). I, quite frequently, try to get fancy in my settings and I invariably forget something. I've made a determined effort lately to stick with certain basic settings (center weighted, central focus point, TV mode - I shoot sports and shutter speed is more important to me) and master them then move on. Works for me in my situation, your settings may vary. I think you can set yours up for AV and watch the metering mode to address these band pictures.

BTW, I did these band shots the last 4 years. Thank God my son finally graduated!

Brice

[KellyL]

Brice...not testing you...just knowing you are watching my back! I would probably need to open the picture up in DPP to find out what my metering mode is. Once again, since I am just now experimenting with metering modes, I still get the icons confused.

I tried to use fill flash according to Kirk's instructions today. I need to read John's Blog.

And my one daughter just graduated from band and my second is in her second year.

[JohnC]

Originally Posted by Brooks

John, you're right. For literally decades I've always thought of the half stop between f8 and f11 as f8.5 or f8 and 1/2. It wasn't until I started shooting digitally that I learned of f9.5. F9.5 just seems so strange to me. This digital stuff is the devils work!

I had the 1/2 stop and 1/3 stop numbers drilled into my head by my college instructor in the late 70s. But even with that I always say things like "betwen 8-and-a-half and 11." I just try to be more careful about it in written conversation or when writing a tutorial.

[heartseye]

Mind you, I doubt seriously if any camera/lens combination on the planet can repeatably select ANY camera-set f/stop to within a half to a quarter stop accuracy anyhow........

[Max@Home]

Originally Posted by KellyL

Here is the question of the day, which is why I did not use a flash last night. When I turn my flash on, my shutter is limited to 1/250.

...a bit more precise, please

...do you mean limited to 1/250sec maximum speed? Both on-camera, but easier on your 580ex you can set HiSpeedSync which takes that treshold away, but be careful, if you shoot (a lot) faster, the shutter-curtain is closed before the full flashlight-blow is recorded...

...or do you mean in Av you ONLY get 1/250 ?? in that case you have a CustomFunction active! On 20D C.Fn.3-Flash Sync Speed in Av-mode: 0 = auto, 1 = fixed at 1/250, on 30D the same C.Fn. ...

...and if I had used my Canon 580EX, I would have equipped it with the Fong Diffuser. I was also using the 70 - 200 on these shots which put me at quite a distance from the subjects.

...at quite a distance OUTDOORS the Fong renders the flash worthless, even for fill, unless you point the 'lid' straight at your subjects and use FEC +2 - +3... distance too far, flash too weak, light too diffused... a 'betterbeamer' would have helped you more...

...you have done GREAT studies with the Metz, why not do these over with the 580 and the Fong ?? Take notes on how you 'pointed' it, as that won't be in EXIF ...

...some observations, *my* €0.02 worth...

Kindest regards!

Max@Home

[Wes]

What a GREAT thread!!! Thank you everyone for sharing your knowledge.