Ron's Photography Notes (1 Viewer)

Doing some reading. Taking some notes.

I am going to jot down thoughts little by little throughout

this thread as I learn tidbits about photography.


Without anyone getting too technical or moving too far

ahead of where I am on the learning curve, I just want to

get clarification on some of the things I am coming to

understand.

For instance:


It is being recommended that as a beginner, I start with

Aperture-priority AE. It allows me to select the aperture

and the camera automatically selects the shutter speed.


* The higher the number the lower the Aperture. So a

22 aperture is smaller than a 2.8.


* A larger aperture keeps the background out of focus

while keeping the subject in focus.


* A smaller aperture keeps everything in sharp focus.

It is being recommended that as a beginner, I start with Aperture-priority AE. It allows me to select the aperture and the camera automatically selects the shutter speed.

Click to expand...

Yes. This gives you more control than the "Green AUTO" mode. You can choose tradeoffs between aperture and shutter speed, you have more control over flash, and you're not forced to immediately do the job of "playing light meter" (which is part of what M mode is about).

The higher the number the lower the Aperture. So a 22 aperture is smaller than a 2.8.

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f-stop numbers are proper fractions. So f/2.8 is larger than f/22 for the same reason that 1/2 of a dollar (50 cents) is greater than 1/20th of a dollar (a nickel).

A larger aperture keeps the background out of focus while keeping the subject in focus.


A smaller aperture keeps everything in sharp focus.

Click to expand...

Yes (within limits).

Originally Posted by Ronald Epstein

It is being recommended that as a beginner, I start with

Aperture-priority AE. It allows me to select the aperture

and the camera automatically selects the shutter speed.

Click to expand...

Good plan.


Remember how your own eyes are similar to aperture-priority:


Your iris of each eye opens wide in dark places, and tightens down in bright sunlight.


The same needs apply to the camera -- in dark environments, you'll end up opening the aperture more, maybe all the way (f/2.8 for example), to receive as much of the precious light as you can.


In bright environments, the human eye would naturally become very small, but your camera breaks this comparison: you can actually pick whatever aperture you want in bright light. Think of it this way: In bright environments you at least have the option of small aperture (like f/22), an option which you don't have (in any practical fashion) in the dark.

Suggested shutter speeds (close aperture if necessary until camera displays an OK speed):


For the 18-55mm VR lens : 1/60th of a second (or shorter)


For the 70-300mm VR lens : 1/125th of a second (or shorter). (The standard formula for this lens would suggest a minimum speed of 1/500th of a second for the telephoto end of the zoom range. But the VR-II stabilizer on this lens is unusually effective.)

Ron,


I agree that starting with aperture priority mode is a good way to learn. Once you get your camera, pay particular attention to how your shutter speed changes in relation to the changes you make in aperture. Remember, the aperture is a fraction representing how open your lens is. The more you open up the lens, the more light you let into the sensor. Therefore, as you open the lens more, your shutter speed needs to get faster so that less light is let in to compensate for the extra light from the larger aperture.


You are also correct that aperture is used to control how much of your photo is in focus. The proper term to use here is "depth of focus" or DoF. However, aperture is only one of a few variables that control DoF. The others are the focal length of your lens and the distance between yourself, your foreground subject and background subjects. How you use these three variables to control DoF is something you will learn with experience.

I know I'm going to end up with a DSLR now sooner rather than later because of all this talk.

I agree that starting with aperture priority mode is a good way to learn. Once you get your camera, pay particular attention to how your shutter speed changes in relation to the changes you make in aperture. Remember, the aperture is a fraction representing how open your lens is. The more you open up the lens, the more light you let into the sensor. Therefore, as you open the lens more, your shutter speed needs to get faster so that less light is let in to compensate for the extra light from the larger aperture.


You are also correct that aperture is used to control how much of your photo is in focus. The proper term to use here is "depth of focus" or DoF. However, aperture is only one of a few variables that control DoF. The others are the focal length of your lens and the distance between yourself, your foreground subject and background subjects. How you use these three variables to control DoF is something you will learn with experience.

Click to expand...

And getting the sense of these things is what I enjoyed the most about dabbling in photography. As I explained in one of the other threads, I had gotten to understand most of these things, Ron and then you start taking risks in manual mode and trying longer exposures, etc. Great fun!

I just can't imagine the beauty of being able to see the results immediately! I used to have to take notes sometimes to remember what I had done waiting for the film to be developed so I could remember how I achieved particular results.

To everyone who is contributing to these discussions...thanks!

It helped me to think of faucets when I was first learning.

For any glass of water you need to open the faucet up to fill the glass.

If you open the faucet up just a little bit, you will need to let the water run out of the tap longer.

If you open the faucet to the widest it will go the water will come tumbling out fast and you will have to close the faucet quickly.

It doesn't matter which strategy you use, you always use the same amount of water in the end.


For any given shot you need to let enough light in to make a proper exposure.

If you have the aperture open just a little bit (f18 to f22 say) you will need to keep the aperture open very long, sometimes more than just fractions of a second, even multiple seconds in some instances. Don't leave it open long enough and you will have a very dark or black photo. You will need a tripod in these instances and any subject motion will appear as ghosting. Do this at night pointed at the stars and you will see trails. The bonus is that the way the laws of physics works allows you to get a very deep field of focus.


If you have the aperture opened up on a 'fast' lens, say f2.8 or faster, you are letting in gobs of light even in a fraction of a second. Hold it open too long and your image will fade to white quickly. You will rarely need a tripod for this much light and you will be able to 'stop action' even with camera shake and subject motion because you are only open for a tiny bit of time. Also only a very thin slice will be in true focus, which is great because you can make the subject 'pop' out of the picture and isolate it from foreground and background elements. But this is bad because if you arent focused on the right thing your picture will be a blurry mess. Pro cameras have exceptional autofocus that helps with this. Lower tier cameras have less elegant autofocus solutions. Even pro cameras can be focused on the wrong things by both operator error and poor visibility tho!


No matter which way you do it, to get a properly exposed image you are using roughly the same amount of light which eventually hits the sensor or film.


Don't forget that ISO factors into this too. And you can continue to use the Faucet analogy here too.

If you were to fill a gallon of water from a tap it would go relatively slowly, even if you had the faucet wide open. If you were to fill a gallon jug of water from a firehose it would fill much more quickly because it has a 'big pipe' of water supply behind it. You can stop down the firehose to faucet like levels but you lose the benefits of its speed and supply.


ISO 200 is very slow to expose but gives very low grain. ISO 1600 and higher expose faster but grain and noise go up comparably.

Here's where buying a more expensive pro camera REALLY pays off tho. If your camera maxes out at 3200 ISO like the D90/D300 does, you can't go faster even if you want to and at the max ISO they will be a grainy mess. If your Camera maxes out at 102000 ISO like the D3S does you can shoot a black bear at midnight and still get some usable shots (tho they will be very grainy) but if you go down to the ISO 3200 level with that camera you will have amazing almost noise free images.


I say this like it's a bad thing but consider this. Few professionals ever really shot at ISO (ASA / ISA) 1600 speed film or faster. So even our 'limited' 3200 speed cameras at the prosumer levels today are much faster than film exposes, with comparably less grain / noise. And the Software to clear up that noise is amazing and easy to use. Those Digicams you have been using? They top out at 400 / 800 ISO at best and are grainy messes at that level.


Sam

I'm going to chime in with some high ISO noise thoughts, since it's been on my mind recently. I shoot a lot of low-light indoor (museum) shots, as well as using indoor shots with no flash (because I dislike the harsh look of it, preferring natural lighting). I've always struggled with the battle between high ISO noise and camera shake due to having to use slower shutter speeds. I try to keep my lens EF-S 17-55 f/2.8 at f/3.5 or f/4 due to the fact that it's sharpest at those apertures, though if that's not doable I will go down to f/2.8 and sacrifice DOF.


Still, I detest video noise. So I was always willing to risk camera shake or motion blur in order to keep ISO at 800 or lower. Older noise reduction algorithms I used always sacrificed fine detail at the expense of reducing noise.


Going up to the 7D gave me much better noise performance than my old XSi (some ISO 800 shots on the 7D are comparable in noise to ISO 400 or lower on the XSi). That was the first step towards my achieving better low-light indoor photos. The second was my purchase of Lightroom 3. The noise reduction in Lr3 is a vast improvement over previous incarnations, and according to online photo sites, is comparable with some of the better noise reduction algorithms on the market. Not the best but pretty close. There will always be detail loss when you use NR, that's just the way it is. But with Lr3, and some other programs like Aperture and standalone NR software, it's now possible to have a great deal of NR with surprisingly low detail loss. In fact, I've been using the Lr3 NR on some older shots from my Rebel XSi and it has literally rescued a great number of shots.


Lr3 has given me confidence to shoot at higher ISOs knowing that it will eliminate a lot of noise. Still if I know there is fine detail I want to catch, I'll still adjust my settings to keep ISO under 800 but in most casual indoor settings I'm not afraid to go to ISO 1600-2000.

Personally, I find some of the noise/grain aversion to be overblown -- much like the aversion to film grain in the HT world.


Often, I find the grittier, grainier look to be quite appropriate for the kinds of images I'd shoot at high ISO. I sometimes even add some grain to lower ISO images too.


Generally speaking, the only noise that is pretty much always bad is chroma noise -- well, of course, we don't want other kinds of artifacts thrown in either. Yeah, sensor luminosity noise isn't quite the same as natural film grain, but it's not *that* far off either.


So it really all depends...


_Man_

BTW, anyone else pick up Criterion's release of Everlasting Moments? I blind-bought the BD in part because of the film's premise involving photography.


_Man_

Man,


Personally I don't find ISO noise equivalent to film grain at all (and for the record I'm very much against DNR in BD releases). Check out this short article on it. To quote:

Film grain is color neutral, as it consist mostly of luminance differences. Digital noise consists of both luminance and color differences, and is most visible in the blue color channel.

Click to expand...

It is that color difference that is most eye-catching. Keep in mind in that article they're using the Canon 5D Mark II full frame camera which is one of the best at dealing with high ISO noise.


For most cameras, perhaps up to ISO 400 the noise is mostly luminance (though different cameras perform differently, as my XSi @ 400 is way worse than my 7D @ 800), but at higher ISOs that there can be a great deal of color noise. That's the reason for my aversion, and knowing Ron's tendencies he's not going to like the look of it either.


If I wanted the film-grain look I'd shoot with film. Or use the "tricks" like Lr3 has for simulating film grain in images. I'd like to start out with the best possible images and then simulate the old ways if needed. In any case, I don't find ISO noise to be equatable to film grain.

Carlo,


I was talking only about luminance noise being somewhat like film grain, not the chroma noise, which I also pointed out as being bad.


Anyway, Nikon typically removes most of the chroma noise from their camera's output -- although that *might* have changed some when they moved to CMOS sensors. Also, as I understand it, chroma noise is actually fairly easy to remove w/out killing significant details. The problem w/ DNR that kills details is more typically associated w/ luminance noise, which is much harder to differentiate from real details in the image.


I generally do not need to do much about (the virtual lack of) chroma noise on my D200 (much like my old D70). I almost never worry about any chroma noise showing up in my D200 for shots upto ISO 1600 -- no, I never shoot above ISO 1600 on it as that requires HI/extended mode and gets very noisy indeed. Nikon's software (like their camera's built-in image engine) also seems to automatically take care of the chroma noise by default near as I can tell.


_Man_

Have to say I have a fairly good grasp of aperture and shutter speed. However, I have a much harder time getting a good grasp of white balance and exposure values. Damned light!! Why can't you be more cooperative?

Originally Posted by Michael_K_Sr

Click to expand...

Just shoot in RAW and you can color balance the image later.

I'm looking at a Blue Crane Tutorial video on the D90.


It is a pretty damn good video guide to the camera and

how take photos in both auto, aperture priority, shutter
priority and full manual modes.


(Gee I hope I got those right)


One of the best buttons on the camera is something

called the Depth of Field Preview Button. From what

I gather, this will allow me to see the exact photo I

am about to take under the settings I have selected.


So, right off the bat, if I am in Aperture Priority and

I am playing around with the different settings I can

tell if my background is going to look blurry or in full

focus just by selecting that button.


I hope I am understanding this correctly.


(BTW, camera is due to arrive today)

I found DOF preview to be helpful when I was starting out and unsure what to expect from various apertures, but now that I have a pretty good idea of what stays in focus at my most commonly used settings, I rarely use it. Basically I use it now only during shots where I absolutely have to know if multiple items in different planes need to be in focus, which is pretty rare.

I think DoF preview was probably *MUCH* more useful back in the 35mm film days, but not nearly so now on digital, especially on the cropped bodies w/ smaller OVF, etc.


You can always just do a quick review of the actual shot on the LCD to see what's in focus and what's not (and how much OoF blur there is, etc). I'm not sure about the D90, but the D200 (and probably all higher end Nikons) can be customized to allow quicker review zoom than the default settings. I have mine set to zoom to ~100% magnification w/ just a press of the thumbpad center point for quick review of focus, camera shake blur, etc.


No, this is not quite as quick as just pressing the DoF preview button, but then again, it's probably more exacting in terms of what you're actually getting for the shot, especially if you don't have eagle eyes.


http://www.dofmaster.com/dofjs.html



_Man_

I pretty much ignore the DoF preview function on my Canon dSLR, too. With my first dSLR (Canon Rebel XT), the viewfinder was small enough that the DoF preview function did not really provide the detailed info I needed, and your viewfinder will get darker, too. By the time I upgraded to the Canon 40D with it's bigger viewfinder, I really didn't need the function anyway.


Live View would probably be a better way to accomplish the same thing, if you wanted to check the DoF before taking the photo. I am not sure, though, if that feature is present on your Nikon D90 (it's on all the newer models from Canon and Nikon). Personally, I do not use Live View on my 40D, either, though.

This has been a good thread just to be reminded of the basics and to learn new ways of explaining concepts.


Ron, you've already come a long way from the guy in the camera shop telling you how to hold the camera.


Looking forward to seeing your growth and progress and being motivated to continue my own!