The Learning Curve

[Pea-n-Me]

Have we done anything on White Balance yet? I thought we did but maybe I'm wrong.

Anyone want to tackle it?

One link to start: http://www.apogeephoto.com/july2004/jaltengarten7_2004.shtml

Adding others:

http://www.cambridgeincolour.com/tutorials/white-balance.htm

http://www.photoxels.com/tutorial_white-balance.html

 

[DueyDooDah]

If I actually took the time to create this, do you think it would be useful? Or am I overgeeking things again?

Yes, this would be useful to those trying to grasp the concepts. Visual aids nearly always benefit in the learning experience.

Overgeek? Naw. I was thinking it was under geeked. You could take this concept one step further. Built properly, the visitor could not only get the lines drawn to see the concept, but then you could zoom in and actually take the photo. Then, there would be no need to go outside in the bad weather. In fact, then we would not need to save money to go to WDW for a photo op. Just pop onto Mark's site, take a few shots (hey, no people so we'd get shots like GDad), and log off. Now, that's what I call a vacation!

 

[Castle crazy]

Subbin in. I've been shooting with a Panny FZ18 and a Fuji 6000. Also have a little Panny TZ5 that I love for a great P&S. I'm waiting for the new camera lines to come out and I want a 'small' DSLR, probably Nikon but we'll see.

Thanks for sharing your knowledge and experiences.

 

[Pea-n-Me]

Welcome Castle crazy.

 

[Pea-n-Me]

Bumping up for new dSLR users.

Also wanted to mention I'm still planning to work more on White Balance (a few posts back) and tackle other subjects. Will hopefully have more time once kids are back in school.

Would love to see participation from others too. Tackle any subect you want!!

 

[Pea-n-Me]

Great Dis thread...

What Did You Learn This Summer

 

[Pea-n-Me]

This is a table and conversation (taken from another thread) which will come in handy to new shooters. Thanks for the information, guys.

What do all of these exposure numbers mean to me and my camera? How can I see what settings I would need to take the same shot?

ISO, aperture, and shutter speed are universal standards. A combination of the three represents the correct exposure for a certain light level. If those settings worked for someone, they will work for you in the same light level. You can also play with those settings to match your camera's capabilities.

Here are scales for ISO, aperture, and shutter speed. If you move down the scale on one, you must move up the same amount on one of the other scales. In other words, if you move two steps down on ISO, you must move either two steps up on shutter speed or two steps up on aperture (or one each on shutter speed and aperture) to get the same exposure.

ISO
6400
3200
1600
800
400
200
100
50

Aperture
f/1
f/1.4
f/2
f/2.8
f/4
f/5.6
f/8
f/11
f/16
f/22
f/32

Shutter Speed
1 minute
30 seconds
15 seconds
8 seconds
4 seconds
2 seconds
1 second
1/2 seconds
1/4 seconds
1/8 seconds
1/15 seconds
1/30 seconds
1/60 seconds
1/125 seconds
1/500 seconds
1/1000 seconds
1/2000 seconds
1/4000 seconds
1/8000 seconds

So if you see the settings "1600, f/2.8, 1/60s" and you wonder how that would work at ISO 400, you can do the translation. ISO 400 is two steps down on the ISO chart, so you have to go up two steps on the shutter speed and/or aperture. If you keep the aperture the same, that means that you need to increase the shutter speed from 1/60s to 1/15s.

What if your lens could only go to f/5.6 and you find shots above ISO 800 objectionable on your camera? Then then "ISO 1600, f/2.8, 1/60s" shot would be one step down on the ISO scale (1600 to 800) and two steps down on aperture scale (f/2.8 to f/5.6), so you would need to move up the shutter speed scale three steps to make up for those changes. That would give you a shutter speed of 1/8 seconds.

These rules are the same for everyone. They don't vary based on camera brand or quality. ISO 400 means roughly the same light sensitivity on a camera phone as it does on an $8,000 full frame DSLR. The cameraphone will show A LOT more noise at ISO 400, but the exposure level is the same.

Incidentally, if you've ever wondered why your camera has an obsurdly fast maximum shutter speed (1/2000, 1/4000, or even 1/8000), it's generally not used because you need to eliminate motion blur on bullets whizzing past you. It's because you sometimes need that to make everything else fit on the scales I posted. On a bright sunny day, you may have so much light that you use ISO 100 on your camera. You may be taking a portrait on want really shallow DOF, so you use f/2.8. That might force you to use a 1/4000s shutter speed just to keep from overexposing. Another alternative is to put a neutral density filter (like sunglasses for your camera) on your lens.

One thing that is not well known about absurdly fast shutter speeds is that the shutter does not actually move that fast, not even close. Most shutters have a maximum speed of about the same speed as the flash sync, often about 1/200 second. For anything faster than that the shutter still moves at 1/200 second but instead of the entire sensor being exposed it is a slit that moves across the sensor.
How this works is for up to 1/200 the first curtain opens and the second curtain follows after the first has finished it travel across the sensor opening. For faster shutter speeds the second curtain starts before the first has finished, reducing the time any portion of the sensor is exposed but still taking 1/200 total time.

So does this matter? Maybe, if the image of the subject is moving in the same direction and at the same speed as the shutter it could cause some odd exposure effects where the subject receives the full 1/200, or in the opposite direction the subject might receive almost no exposure.

How likely is this to occur? Rarely, but if it ever happens at least you know it isn't a problem with the camera.

Very good point. If you ever wondered why the flash mode in which the flash fires at the end rather than the beginning of the exposure is called "second curatin sync", now you know.

If you really want to freeze high speed motion, use your flash. It's usually a very, very brief flash of light. Don't, however, use it in high speed sync mode. It sounds screwy, but the flash duration is longer in high speed sync mode. The reason is that it needs to be lit during the entire time that the first and second curtains are exposing a portion of the frame. With a non-high speed synch flash shot, the first shutter curtain opens the frame, the flash fires, and then the second curtain closes the frame.

 

[wenrob]

I actually printed this out to refer to the other day. I'd never had it explained quite that way before. I expect it to come in handy. (thanks Mark! )

 

[Pea-n-Me]

This Slow Synch tutorial - with pictures - just came this afternoon in my Olympus newsletter if anyone's interested.

http://www.olympusamerica.com/crm/oneoffpages/crm_e-otherflashmodes.asp

 

[Pea-n-Me]

Just doing a little housekeeping here. Ran across this Dis thread and thought it would be handy reading for anyone just beginning.

Tell Me About Your First Months With A DSLR

I know there are a lot of folks around who've just bought dSLRs. Hope you join in. Feel free to share thoughts, pictures, ask questions, etc.

 

[Pea-n-Me]

Need help understanding what this means. Bryan Peterson mentions it a lot in his books (currently reading his Learning To See Creatively.)

Here is an example: "With the aperture set to f/22, I adusted the shutter speed until 1/4 sec. indicated a correct exposure."

What and where is this indication? How does it work? (Shoot, if I could figure that out I wouldn't have to play around so much with settings.) What am I missing? I know it must have to do with metering, but he seems to be saying this information should be given somewhere, somehow. Is he talking about a film SLR?

Can anyone explain it to me? Thank you!

 

[wenrob]

I had the hardest time with this and it took forever and a bunch of questions before I could get someone to understand what I was asking. When you meter and your little meter thingy (lol) pops up, it will indicate if you're over or under exposed in your current settings. If you turn the dial until the mark is right smack dab in the center then that indicates proper exposure. It won't necessarily be 1/4 sec. just whatever is correct for what f/22 is and your lighting situation. It would the same if you were shooting in S mode, set the speed you want and spun your aperture dial until the mark was in the middle. Does that make sense? It took me reading the book twice and lot of questions before that clicked.

edited to add: For me sticking right to the middle I'm under exposed so I go a mark or two to left. I forget what you use but on Nikons it's 'backwards' plus on the left and minus on the right.

 

[InsertWittyNameHere]

I believe when he makes that statement he is shooting in manual mode. In that mode you have to pick both aperture and shutter speed to get a correct exposure. If you picked f8 as the aperture you wanted to use, you would then need to adjust shutter speed until you got a correct exposure.

On the Olympus camera the LCD would indicate + numbers and - numbers if you didn't have the correct combo. Once you got that scale to 0 you would be at the correct exposure. Unless of course you want to over or under expose, in which case you would use the + or - numbers.

Hope this helps

 

[handicap18]

Need help understanding what this means. Bryan Peterson mentions it a lot in his books (currently reading his Learning To See Creatively.)

Here is an example: "With the aperture set to f/22, I adusted the shutter speed until 1/4 sec. indicated a correct exposure."

What and where is this indication? How does it work? (Shoot, if I could figure that out I wouldn't have to play around so much with settings.) What am I missing? I know it must have to do with metering, but he seems to be saying this information should be given somewhere, somehow. Is he talking about a film SLR?

Can anyone explain it to me? Thank you!

I tried looking for a shot you see in the view finder of one of the Olympus' dSLR's but couldn't find one that has the meter. So I found this from the E-510's LCD monitor:

You can see on the top Between the P and the -0.7 the "meter" (I'm assuming, though it could also just be how the exposure compensation is set since it says -.7 and there are 2 bars the to the right). - on the left and + on the right. In the middle the is a larger square box. This is the center. Underneath you see the same square box (just above the date) then 2 smaller boxes to the left. This says the meter is reading the settings as being 2/3 stops underexposed. If those 2 small boxes weren't there and there were no boxes on the right side then the meter would indicate a "correct exposure"

In this image from the Nikon D60:

You can see the '0'. Underneath the meter is strong to the left indicating an over exposed image(with Nikon the + is on the left and - on the right):

In this image from the Nikon D60:

You see just 2 lines on each side under the '0'. This indicates a "correct exposure"

And in this image

You see the lines going to the right to indicate an under exposed image

 

[wenrob]

Kyle, on my D40 the meter is + to the left and - to the right. Is it different on the D60 or other Nikons? This always throws me because a histogram is opposite and I end up over/under exposing because I'm spinning the dial to the histogram in my head instead of the meter in my viewfinder.

 

[handicap18]

Kyle, on my D40 the meter is + to the left and - to the right. Is it different on the D60 or other Nikons? This always throws me because a histogram is opposite and I end up over/under exposing because I'm spinning the dial to the histogram in my head instead of the meter in my viewfinder.

Hmmm... your right. On the D50 + is on the left and - is on the right:

I guess I was thinking more of which direction I was turning the dial.


Here is a Canon 40D:
The + is on the right and - on the left:

I'll go back and correct the Nikon D60 description I gave above.
Here is the D60:

+ to the left and - to the right

I still can't find an image of an Olympus' dSLR that has the meter in the view finder. Do they even show it in the view finder?

 

[Pea-n-Me]

Thank you all for replying so quickly!

I am familiar with that bar, and sometimes turn it either left or right to adjust exposure (and darn if I can tell you which way does what, it always confuses me too ), but I didn't realize that a zero reading means correct exposure - you guys are great! I will need to study and fool around with that more.

I've read tons of stuff but I haven't been great about reading my own manual. It's small and the corners are curled up from it being in my slingbag. After this I'm going to take it out of there, flatten it, and look at it more often. I also have the DVD that put me to sleep initially - I'm probably ready to watch that again sometime soon, I'm sure I'll get more out of it than I did when I first got the camera.

I couldn't find any pictures of the viewfinder either on some of the sites I like that go over technical aspects of my camera. I'm definitely going to have more questions on other features as my mind is able to absorb new concepts. I really appreciate the help.

 

[InsertWittyNameHere]

Thank you all for replying so quickly!

I am familiar with that bar, and sometimes turn it either left or right to adjust exposure (and darn if I can tell you which way does what, it always confuses me too ), but I didn't realize that a zero reading means correct exposure - you guys are great! I will need to study and fool around with that more.

On the E510 that bar in P,A or S mode determines exposure compensation which you can adjust using the +/- button and the dial. The only time it is used to determine the actual "correct exposure" is if you use Manual mode.

Hope this doesn't confuse you. It took me about a month and rereading the manual a few times to figure that out.

 

[wenrob]

If it's any consolation my manual was zero help in that dept. It told you where the meter was and which way was what but did not explain how to get a correct exposure with it. At least not in a way I could understand. And Bryan Peterson is awesome but I think there was only a brief mention on how to use the meter that way. He talks about the meter quite a bit but assumes the user knows what he's talking about, lol. Which, I guess if your manual was clear you would but I didn't find mine all that helpful beyond what the controls do.

 

[Pea-n-Me]

On the E510 that bar in P,A or S mode determines exposure compensation which you can adjust using the +/- button and the dial. The only time it is used to determine the actual "correct exposure" is if you use Manual mode.

Hmmm. That's probably why I'd never seen it at least somewhere. (I have read through technical specs many times from places, like Worniak, dpr, Olympus, etc.) I'll have to play around with it more.

He talks about the meter quite a bit but assumes the user knows what he's talking about, lol.