# Exposure & Your Photographic Triangle



## Dominantly (Jan 4, 2010)

*Intro:*

So I figured I would shed a spark on some basics, learn a little while doing it, teach a little more, and provide a catalyst to get other; more knowledgeable (there is always someone better) people in here to compound on this.

I know quite a few people have been helping out some of the newest photographers here (Mostly Sunny ), recommending books, manuals, etc... Well I thought I would dump some info in here, for them to look through. On top of that I would like to have a few workshops where the material is actually tried out with results posted.

Here is http://www.thephotoforum.com/forum/...tering-white-balance-jpeg-vs-raw-formats.html


So an Exposure, whether you are using film or a digital camera, is the act of allowing light to come in contact with your photosensitive material (film, or Image sensor).
The act of obtaining a correct exposure involves properly adjusting your 3 key factors; Shutter Speed, Aperture, and ISO.

*Aperture-*
Your camera will display a variety of Apertures, IE. 4, 5.6, 8, 11, 16, 22, and so on. Each of those numbers is going to relate to a specific opening inside your lens, called an _f_-stop (_f_/4, _f_/11, _f_/16, etc). The whole purpose of these _f_-stops is to control the amount of light that reaches your sensor or film during the exposure.
The smaller the f-stop number, the LARGER the opening. The larger the _f_-stop number, the SMALLER the opening.
Where does this _f_-stop stuff come from? Well _f_= Focal length (of your lens), the / means you divide by, and the number means the stop in use. So, a 35mm lens at _f_/1.8 would have a aperture opening of 19.4mm... Make sense?

Each time you drop down from one _f_/stop to the next (_f_/4 - _f_/5.6), you cut the light hitting the medium in half, and if you go the other way (_f_/8 - _f_/5.6) you double it. Now most cameras offer 1/3rd stop intervals as well, you will see this when adjusting your Aperture..... *f/4*, _f_/4.5, _f_/5,* f/5.6*, _f_/6.3, _f_/7.1, *f/8*, _f_/9, _f_/10, *f/11*, _f_/13, etc....(bold is basic full stops).

Now besides changing how much light is allowed to enter and hit your sensor, the size of the Aperture determines the DEPTH OF FIELD for a photo. A smaller Numerical f/stop value and larger Aperture like f/1.4, has a SHALLOW depth of field whereas a larger f/stop Numerical value and smaller Aperture like f/22 had a larger depth of field.

So if you have a subject on a field that's 10 ft away and you set your Aperture to f/1.4 (or your lowest) and shoot them, you will notice how everything leading up to them in the foreground is blurry, with them in focus, and then everything behind them blurry. This is selective focus and we will talk more about it later. NOW on the opposite side of that, if you set your aperture to F/22 and shoot them again you will have more of the photo in focus. This is a storytelling Aperture and is good when you have a background or foreground that you feel will enhance a photograph.

Same Shutter Speed, just adjusting the ISO to compensate your the smaller Aperture:

f/5.6 1/50 ISO 200






f/8 1/50 ISO400





f/11 1/50 ISO640





f/16 1/50 ISO 1250





f/22 1/50 ISO 3200





f/29 1/50 ISO Hi.3









*Shutter Speed-*

So with the different models of cameras out there, we have different capabilities as far as shutter speed go. We can go from 1/8000th of a second, down to 30 seconds, or BULB (gives you the ability to open and shut the shutter using a remote -ideally).
The Shutter and Aperture work together, the shutter is what is opening to allow the light hit the sensor, and the aperture is what is controlling the AMOUNT of light hitting the sensor.
We have the same halving or doubling that we had with Aperture, here with Shutter speed. For example if you go from 1/1000th of a second to 1/500th, you have cut the shutter speed in half, or if going the opposite, you've doubled it; 1 full stop.... As with Aperture, you also have 1/3rd stops which are there to give you the ability to really dial in your exposure.

*Shutter speeds and what they do:*
1/4000 to 1/2000.......... Stop a Hummingbirds wings
1/1000 to 1/500............ Freeze a human running and most athletes
1/250 to 1/60............... Stop most daily movement and handheld blur safe
1/30 to 1/8.................. Blur motion (camera should be on a tripod)
1/2 to long time............ Dark scenes, night time, etc (tripod only)

*ISO (International Organization for Standardization)-*

ISO is basically your Image Sensors, sensitivity to light, or your film speed in traditional cameras.
With digital cameras we generally have a range from 50-3200. 
** So lets say we both have the same camera setup, you set your camera to ISO 200, f/5.6 and to obtain a correct exposure, your cameras light meter tells you to set your shutter speed to 1/250... now I set my camera to the same f/stop- f/5.6, then change the ISO to 100 and meter the same subject, my camera tells me that in order to get the correct exposure I need 1/125th of a second. Thats a one stop difference because your cameras sensor was twice a sensitive as mine, allowing a faster shutter for the same exposure.

LAB:
Now if you want to try this out, grab your camera and go into manual mode, set your ISO at 200, and f/8. Now point the camera at something in the room and adjust the shutter speed until your light meter tells you that you have a correct exposure (now write that down). Go back into your menu and change your ISO to 400 and point it back on that same subject in the room and adjust your shutter speed to get the correct exposure (write it down again), and now do the same thing with ISO 800.....

My straight out of the camera results:
f/5.6 1/40 shutter, ISO 200









f/5.6 1/80 shutter, ISO 400









f/5.6 1/160 shutter, ISO 640











As you increased your sensitivity by 1 stop, you should have seen close to one full stop difference in your shutter speed requirements.
So we've learned that when you increase your ISO, you increase the sensitivity of your image sensor, allowing you to use a faster shutter speed. You can do the same thing by leaving your shutter speed constant and adjusting your Aperture to get the correct exposure.

So ISO is awesome right? Why not set it as high as it will go and leave it? Well, the downside to increased ISO is you gain NOISE and lose contrast as you increase it. SO your sharpest photos with the least noise and highest contrast will be seen at your lowest ISO. You will have to use it where necessary in order to achieve your desired results. THe good news is that with the advance$ in technology, we are getting higher and higher ISO's with le$$ and le$$ noise. 


*Light Meter-*

Alright, so I am going to tell you how this works, just like it was told to me, and thats with an analogy (love those things).

We are at your sink, your faucet is your cameras Aperture which is at f/8; now lets say the opening to your faucet is the SAME SIZE. Your handle to your faucet is your Shutter Speed. Below the faucet are 100 tiny empty buckets that represent your ISO. Now your camera's LIGHT METER is going to determine how long your faucet handle (or Shutter) needs to be open in order to fill those buckets with water (or Light) based on the size of your faucet (or Aperture). If the faucet is left on too long, you overfill (or Over expose), if you leave it on not long enough you Under fill (Underexpose).

Ok, so we have a basic over view of the 3 elements that go into properly exposing your photograph. We have learned that they are all interlinked, with the light meter as the ring leader pulling it all together.

As you can probably tell, there are many different combinations to get a correct exposure on any given subject. What you need to determine is your CREATIVE EXPOSURE. What this means is if you are shooting a highway at night, instead of adjusting your 3 ring combination to give you a motion stopping exposure, it may be more creative to use a long shutter and get some motion blur. Or on the opposite end, if you are shooting a Hummingbird; you may want to use a faster shutter to try and stop the wing motion (or slower to blur it).... It's all really up to you and your vision.


So, I'll end this one here. Hope it helps someone understand some of the basics.. :thumbup:


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## zeto88 (Jan 4, 2010)

How did you know 400 was (1/60)?


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## Dominantly (Jan 4, 2010)

zeto88 said:


> How did you know 400 was (1/60)?


Well, when I set my shot up for ISO 400, I looked through the viewfinder and adjusted the shutter until the cameras light meter told me it was properly exposed, then I read the shutter and it was 1/60.


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## zeto88 (Jan 4, 2010)

Oh lawd. D:
Make a video tutorial with a Nikon D90!
... I dare you.


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## Dominantly (Jan 4, 2010)

zeto88 said:


> Oh lawd. D:
> Make a video tutorial with a Nikon D90!
> ... I dare you.


Did you do the lab and have similar results, or way off? I guess I'm just not sure if you were having and issue, or what... I could help if thats the case...

As for the video, I thinks not......


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## zeto88 (Jan 4, 2010)

I don't understand how to determine what I need to do via the light meter. 
Hmmm, I'll work it out.


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## Dominantly (Jan 4, 2010)

zeto88 said:


> I don't understand how to determine what I need to do via the light meter.
> Hmmm, I'll work it out.


Well, I can help.
So if you were to grab your camera (D90 I assume)... and then set it up at F/8, ISO 200 in manual mode. Point the camera at a fairly well lit sunject like a blank white wall, or so. Look through the view finder and look at the light meter, it will look like +......0......-
Now you will have to adjust it to get the correct exposure, so adjust the rear thumb wheel until you see the bars start to head towards the 0 (you have to be looking through the viewfinder)... to the - is under exposed, to the + is over exposed. So if it looked like this   *+*...*|*.*|*.*|*.*0*......*-*  you would adjust your thumbwheel to the RIGHT, increasing shutter speed and reducing your Over exposure. Once you get to the 0, you have a proper exposure.



Mine in my example will of course be different because I am metering off a subject in my house, which will differ from someone else trying this.


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## IgsEMT (Jan 4, 2010)

Oh Dominantly,
Well, I hope you happy, you just eliminated 10,000 new threads "what is A mode and what are best settings to shoot a wedding" 
thanks for you time, I hope people reading that will appreciate it and learn from it rather then doing "above".


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## Dominantly (Jan 5, 2010)

IgsEMT said:


> Oh Dominantly,
> Well, I hope you happy, you just eliminated 10,000 new threads "what is A mode and what are best settings to shoot a wedding"
> thanks for you time, I hope people reading that will appreciate it and learn from it rather then doing "above".


Thanks:thumbup:

I mentioned to Mostly Sunny that I would post some info up to help her learn some of the basics. So I figured I would post something like this that other people could use to guide them through some of the fundamentals.

I plan on doing a few different guides covering various features, so if you or anyone else has any input on this stuff, please add.


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## Caity (Jan 5, 2010)

:hug:: You wonderful man you. I wish when I had started I had it laid out so simply for me!! It's a perfect beginner's starting point. 

Would you mind if I printed this out and gave it to a friend? The manual is too "technical" for him. He refuses to move out of Auto. We're going to change that!


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## Dominantly (Jan 5, 2010)

Caity said:


> :hug:: You wonderful man you. I wish when I had started I had it laid out so simply for me!! It's a perfect beginner's starting point.
> 
> Would you mind if I printed this out and gave it to a friend? The manual is too "technical" for him. He refuses to move out of Auto. We're going to change that!



I'm just glad it all makes sense, I sort of wonder with thoughts, I'm surprised it stayed on topic 

You are more then welcome to copy it....:thumbup:

I think I am going to go more in depth on the light meter tomorrow. I will probably add in White Balance, and Raw vs Jpeg....


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## Bitter Jeweler (Jan 5, 2010)

Dominantly said:


> I mentioned to Mostly Sunny that I would post some info up to help her learn some of the basics. So I figured I would post something like this that other people could use to guide them through some of the fundamentals.
> 
> I plan on doing a few different guides covering various features, so if you or anyone else has any input on this stuff, please add.


 
I am glad you have the time for it. :thumbup:
Good on ya'!

:cheers:

Oh, and the Faucet/Light Meter...Fricken' brilliant.


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## mrdemin (Jan 5, 2010)

Well done, should be stickied!


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## Caity (Jan 5, 2010)

Yes the faucet/light meter deal was BRILLIANT. My mind works in that way so seeing it compared to something I fully understand, way way easier to "get". 

I'll be on the lookout for more of these guides!


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## FrankLamont (Jan 5, 2010)

Even if something like this is put up, even stickied... some will always ignore and post anyway. But of course, a rather accurate thread, so...


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## Dominantly (Jan 5, 2010)

I love analogies.. That was how I learned about the relation of the triangle and light meter right off the bat, and I guess I retained it because of the way it was introduced.

When I was an instructor I would try and make them up to help people use different parts of their brain to retain and apply new ideas.

I still googled a few things that were hazy just to make sure I put out good info...


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## IgsEMT (Jan 5, 2010)

> I plan on doing a few different guides covering various features, so if you or anyone else has any input on this stuff, please add.


Sure, I'll add 5cents, what's the topic?
The only sad thing is that, I can almost guarantee, that comes Friday someone will post a thread asking the questions to which you answered.


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## Dominantly (Jan 5, 2010)

IgsEMT said:


> > I plan on doing a few different guides covering various features, so if you or anyone else has any input on this stuff, please add.
> 
> 
> Sure, I'll add 5cents, what's the topic?
> The only sad thing is that, I can almost guarantee, that comes Friday someone will post a thread asking the questions to which you answered.


Well tomorrow I plan on doing more on teh light meter, White Balance, and Raw vs Jpeg files...

So maybe you could share some knowledge on one of these----spot, center weighted, and matrix metering modes, Flashes, Exposure Compensation, Auto Focus modes... Or maybe even come up with a lab for people to try out to show something they learned.
No pressure though...


It's a heck of a time machine. You start typing, next thing you know it's 3 hours in the future


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## IgsEMT (Jan 5, 2010)

> It's a heck of a time machine. You start typing, next thing you know it's 3 hours in the future


No $h1t!, I began typing my response, I think it was 12am on my end, now its 2 - not sure what I did in the middle though


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## altitude604 (Jan 5, 2010)

Dominantly said:


> Where does this _f_-stop stuff come from? Well _f_= Focal length (of your lens), the / means you divide by, and the number means the stop in use. So, a 35mm lens at _f_/1.8 would have a aperture opening of 19.4mm... Make sense?



Well I'll be jiggered... that totally answered one of those questions I had in the back of my head.


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## timfrommass (Jan 5, 2010)

Isn't this just a reworded version of the same section in the book "Understanding Exposure" by Bryan Peterson?  The order is the same, the exercise is basically the same, and the bucket analogy is the same.  

-tim


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## IgsEMT (Jan 5, 2010)

> Isn't this just a reworded version of the same section in the book "Understanding Exposure" by Bryan Peterson? The order is the same, the exercise is basically the same, and the bucket analogy is the same.
> 
> -tim


I have it somewhere, never read it .
But, hopefully ppl here will read the 411 and leeeeeeeeaaaaaaaaaaarrrrrrrrnnnnnnn


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## Dominantly (Jan 5, 2010)

timfrommass said:


> Isn't this just a reworded version of the same section in the book "Understanding Exposure" by Bryan Peterson?  The order is the same, the exercise is basically the same, and the bucket analogy is the same.
> 
> -tim



I've never read "understanding exposure", but I have read other books by Bryan Peterson. I have also read "Lighting, by______" (will enter name later when I find it).

You can't change the principles. So reworded principles are an example of someone learning something, and then trying to share the info with using their own words/spin.
I was waiting for someone to have heard the bucket analogy before. Once you've heard/read it, it makes complete sense and stays in your head.


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## ajandnickysmom (Jan 5, 2010)

Awesome!  I've taken 3 different classes over the past year... and this explained it much better then what i've been told!  Keep posting..  I love this crap!  I wish i was  home with my camera so i can play along!  Will have to do that later!  Maybe they should just open a forum just for you to teach! LOL!

THANKS!  And i promise i wont post stupid questions that have already been answered in one of these threads!

When's my the next class!


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## Bambi (Jan 5, 2010)

thank you for this. I have copied it to a document to keep on hand.


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## Caity (Jan 5, 2010)

I've forwarded this to three people so far... And you could just SEE the lightbulbs above their heads light up! Thanks again!!!


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## Dominantly (Jan 5, 2010)

Updated with photos.


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## vinniemac3 (Jan 5, 2010)

haha yep that was in understanding exposure. i just read that section the other day. great book happy i ordered it. and better news, my new cam came in today but im at work til 7 am so im stuck here and cant touch it til i get home in the am. go figure.


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## Dominantly (Jan 5, 2010)

Hmm, I wonder if all his books are the same.
I own his photography field guide, and that's where I learned that catchy bucket analogy (although he has bees collecting water...)


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## vinniemac3 (Jan 5, 2010)

haha yep he uses the bees catching water deal in understanding exposure to. i guess if something works stick with it.  im hoping it works for me. i cant wait to play with my new toy tomorrow, its my first slr cam so we'll see how it goes


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## mostly sunny (Jan 5, 2010)

OMG-- Thank you so much!
I plan to try this out after work tomorrow.
= )


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## Dominantly (Jan 6, 2010)

I have been working on a second one for a little while now. I will post it up tomorrow as I am getting kind of too tired to keep typing, so in the sake of keeping it somewhat logical, I'll resume it tomorrow


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## mostly sunny (Jan 6, 2010)

Ummm, this is going to require some thought on my part.  Since I am not allowed to work out for another day.. I will do this when I get home.. Oh HOMEWORK!  Why am I super excited about this?


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## GFreg (Jan 6, 2010)

Great work.


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## mostly sunny (Jan 7, 2010)

Umm, on my camera I can't do this in Manual. It won't let me change the F stop.

What are all those other numbers in my view thingy, and on top of the camera-  Don't  answer.. I'll figure it out.  For the moment, the camera has won. I am off to bed!


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## bazooka (Jan 7, 2010)

Must.... read..... Manual.


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## Dominantly (Jan 7, 2010)

mostly sunny said:


> Umm, on my camera I can't do this in Manual. It won't let me change the F stop.
> 
> What are all those other numbers in my view thingy, and on top of the camera-  Don't  answer.. I'll figure it out.  For the moment, the camera has won. I am off to bed!



Well, I can't really say where things are on your 7D as I have never seen one (or messed with any Canon for that matter).
But I would be willing to bet you can change your f-stop in manual, along with everything else.

Maybe someone with more experience with Canon can help you out, if the manual isn't helping.


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## melrose09 (Jan 7, 2010)

This thread is so helpful!  I followed along with my camera and learned within several seconds that i have to get a tripod, like today!  I've just been trying to keep my shutter speed at a handholdable speed, and it's just not working...and I think I missed the amazon sale from yesterday  Apparently they had 25% off all photography accessories and I totally missed it.  Thanks so much for posting this!!


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## Dominantly (Jan 7, 2010)

Glad it helped.

BTW I just moved from the Oak Harbor area to San Diego, and I kinda miss it there


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## melrose09 (Jan 7, 2010)

Dominantly said:


> Glad it helped.
> 
> BTW I just moved from the Oak Harbor area to San Diego, and I kinda miss it there



Navy?


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## Dominantly (Jan 7, 2010)

Yup.


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## melrose09 (Jan 7, 2010)

Ah, thought so  We just got here and so far we LOVE it.  100 times better than Jax.  Lots more interesting things to photograph!  I can't wait for the tulips this spring.  I'll be sure to post pics of that awesomeness!


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## Lazy Photographer (Jan 7, 2010)

Very interesting read, thank you. Learned a few things from it. Gonna read Part II next.


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## y0aimee (Jan 7, 2010)

I'm bumping this to the top.  This is a must read for beginners!  Thanks for sharing!


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## IgsEMT (Jan 8, 2010)

> Umm, on my camera I can't do this in Manual. It won't let me change the F stop.
> 
> What are all those other numbers in my view thingy, and on top of the camera- Don't answer.. I'll figure it out. For the moment, the camera has won. I am off to bed!


UNLOCK the wheel in the back of the camera


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## Dominantly (Jan 8, 2010)

Thanks for everyone's comments, glad it was helpful.


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## mom2eight (Jan 10, 2010)

Thank you thank you thank you!  It makes so much more sense now!  I used this today when I shot in bright sun.  I was not exact with exposure but due to the conditions your tutorial helped me so much.


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## Rockford (Jan 15, 2010)

Dominatly, Through out my learning years, I always said its the way the instructor conveys the lesson does one learn. You my friend, have the nack.
 To you Sir, I raise a glass of red.  Thank you

BTW I lived in RB in the early 80's, Did you get photos of the fires that did so much damage a few years back. I remember I was on the roof with a hose the first year living there. The fire burned it self out at the edge of Lake Hodges. Nearly burned our house down.


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## Dominantly (Jan 15, 2010)

Rockford said:


> Dominatly, Through out my learning years, I always said its the way the instructor conveys the lesson does one learn. You my friend, have the nack.
> To you Sir, I raise a glass of red.  Thank you
> 
> BTW I lived in RB in the early 80's, Did you get photos of the fires that did so much damage a few years back. I remember I was on the roof with a hose the first year living there. The fire burned it self out at the edge of Lake Hodges. Nearly burned our house down.


Thank you my friend.. I am use to teaching Sailors, so I've tried to adapt over the years to put stuff out in an interesting, quick manner..

I didn't get any photos of the fire. Actually, I moved about 4 months before the fires, to Washington. The condo I was living in burned down, so I was glad I left when I did. I recently moved back, and hope to avoid fire photo opportunities.:mrgreen:


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## zeto88 (Jan 19, 2010)

Bump.
This should be up the top of the sub-forum.


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## E-Stew (Jan 21, 2010)

I've just discovered this forum and joined, and already I'm grateful.  Thank for you this very informative instruction piece--what I once had trouble understanding is now much more easier to digest.  Still a lot to take in, but thanks for making the road a bit easier to follow.  Your time and effort are greatly appreciated.


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## Dominantly (Jan 21, 2010)

Welcome.

Thank you for the support. Look forward to seeing your future posts!


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## Ccauceg (Jan 21, 2010)

Sticky!!!!!


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## AliasPros (Jan 21, 2010)

zeto88 said:


> Oh lawd. D:
> Make a video tutorial with a Nikon D90!
> ... I dare you.



I will produce and market it! All high definition legit!!! 

ALIAS


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## Natural_Disaster (Feb 5, 2010)

I actually found this thread by accident and im so glad i did! Thanks so much for putting this information here for those of us who are just getting started!


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## flashgordio (Mar 9, 2010)

well done ...will go back to my manual,it might make a bit more sense now, i may even be able to use one of the features on my camera now.
 where do you find the time?????


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## Dominantly (Mar 9, 2010)

I only work to about 11am everyday... so it's either go out and spend money, or occupy my time at home somehow


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## astig07 (Mar 10, 2010)

wow! ive been looking/searching on how to get a right exposure! this topic gave me all the answer i was looking for!! thank you so much!!!:hug::


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