1/2/3 Stop Mean
I Have a 400D. Can someone please explain to me what the term 1/2/3 Stop means. in plain terms. I have read my booklet through and I just cannot undersatand what this means exactly. replies would be more than welcome.
Bob
Dumfries & Galloway
Scotland
Bob
Dumfries & Galloway
Scotland
0
Comments
It all has to do with amounts of light.
If you take a photo at: shutter 1/1000, f8, iso 200, and it is to bright of a shot.
You may try to reduce the light entering to camera by 1 stop.
you could do this by:
1) Having the shutter speed faster. 1 stop would be cutting the shutter speed in half. So if the first shot was 1/1000 of a second, this shot would be 1/2000/sec.
2) The "f" number is aperture size. If your first shot was at f8 and you want the shot 1 stop darker, you would go to f11. That would allow 1/2 of the light into the camera through the lens.
3) The ISO number deals with the sensitivity of the sensor. I wish I could explain it, but I can't. It's an electronic thing.
It's much like film, asa 100 is a slower film and used outside in bright light, 200 film is kind of a everyday film, 400 was used for indoors.
So, if you shot the above shot at ISO 200, and it was to bright, you would move to an ISO of 100 to reduce it by a stop.
If you did all 3 of these things, your shot would be 3 stops less bright than your original shot.
If I messed up, I'm sure someone will straighten it out.
Basking in the shadows of yesterday's triumphs'.
Mmmmm Thanks Davev,
I am a complete learner. I know how the ISO works. mine goes up to 1600. I have moved from Auto and I tried the Manual but got somewhat confused with the Shutter speeds and aperture. So I went onto 'P' Programme and I have been taking some nice shots because it automatically sets the shutter and aperture. I know how to change the shutter speed and aperture but its knowing what figure to put them on. I will hopefully sus it as I am determined to win. Any other comments from anyone else would be most welcome. Thanks all for having patience with me.
Bob
Nothing wrong with the "P" mode. But you lose control over some of the creative aspects of your equipment.
I use the "A" for aperture priority.
I set the aperture and ISO, the camera meters the frame and sets the shutter speed for me.
In using it this way, I have some control over the DOF. (depth of field)
A large aperture (small f number) will give you a shallower DOF, a small aperture (large f number) will increase the DOF.
To isolate someone or something from the background, most folks use a large aperture. (as large as the lens can go, f1.4, f1.8, f2.8)
For something like a landscape shot, where you want everything to be in focus, you'd use a smaller aperture. (like f11 or f16)
Basking in the shadows of yesterday's triumphs'.
Wow Dave, that reply was brilliant. I really do understand what you have said. I will go and practice the 'A' as you have outlined. Your pics are fab to say the least.
I was about to ask you about the Depth of Field in basic terminology. I think I have a rough idea what it means but I would like to hear what you have to say about it.
Thanks Dave I really appreciate what you have told me.
Bob
In answer to Dave's reply, I have selected Av for changing the depth of field and I find the readings do not go below f5.0 minimum and f32.0 maximum. To quote Dave's reply, " To isolate someone or something from the background most folks use a large aperture( as large as the lens will go) f1.4, f1.8 f2.8" Can you please explain how I can overcome this when I can not get below f5.0. Comments please.
Thanks again
Bob
Bob:
I'm still pretty much a rookie too--and I don't have the cash for the high end lenses with the f2.8 and lower so I'm often dealing with apertures starting around f5.6. I see you on your profile that you have a "Bigma." I do too--and I use that a lot. Basically, the higher you are zoomed, and the closer the subject is to you, the shorter the depth of field will be.
In each of the three following shots, the subject was about the same distance from me, about 10 yards or so.
Here's an example with a pretty short DOF. It was shot at f5.6 and zoomed at 400 mm. My daughter was pretty close, so you'll see that the both the closer girl and the background are both out of focus--because the DOF was really short.
By contrast, here is a shot of my daughters coach. This one was also shot f5.6, but with a zoom of about 160mm. You can see that the background is still blurry, but if you look closely, you can see a good portion of the grass before and after her is in focus.
Finally, I switched to a 28-135mm and took this last photo at f3.5, but at 28mm zoom. You'll see that despite the wider aperture, the DOF is still really deep--the background is still sharp.
I know these aren't quite as dramatic of examples as davev's post, but figured I'd show you what can be done with the type of lenses you and I seem to share. PS: I generally shoot full manual. Since I shoot mostly sports, once I get the exposure dialed in I can just worry about capturing the action. However, on days when there is patchy clouds or the sun is going down and the lighting keeps changing, I'll use Av mode as well...
Hope this helps.
Will
________________________
www.willspix.smugmug.com
A more expensive lens will have a constant aperture. A 70-200L f2.8 only has one f stop number.
This lens will open to F2.8 throughout the zoom range.
Will is right. There is more to DOF than just aperture size.
Distance to the subject also comes into play, as does the distance from the subject to the background. The mm of your lens (50mm, 100mm, 200mm) also changes what happens to the background.
I used f1.4, f1.8, and f2.8 because of the bokeh (blurred background) is normally a little easier to get.
So, if your lens will only open as wide as a f5.6, you would need a combination of other things to blur the background.
You could:
1) move your subject closer to you.
2) Zoom in on your subject keeping the same "f" stop.
3) Have your subject move farther away from the background.
So, lets use one of your lenses as an example.
Canon 400D camera, 60mm f2.8 lens.
So at 1 meter away, at f2.8, this will give you a DOF of .028 meters.
At 10 meters away, at f2.8, the DOF is 3.034
Same thing only f11.
At 1 meter, it's .113 meters
At 10 it's 18.327
This can be really confusing when you first start out, but hopefully this is helping you out Bob.
Here is a link to an on line DOF calculator.
You can put in your camera and focal length of your lens, then change the numbers for the f stop and distance to your subject. (the scale is in meters) I think this will help you understand a little better.
http://www.photo96.com/dof/
Basking in the shadows of yesterday's triumphs'.
Thanks ever so much Will. I appreciate the way you have explained evrything so clearly. I will read it over and digest what you have said and try out what you have explained. I am sure that I will improve on my skills in due course.
Thanks Will.
Bob
Bob, to maximize your learning curve in photographic theory and function of the camera, might I recommend the following:
Understanding Exposure by Bryan Petersen
Blue Crane 400D DVD
Both of these are very well done, and worth their weight in gold for the new dSLR user.
50mm 1.4, 85mm 1.8, 24-70 2.8L, 35mm 1.4L, 135mm f2L
ST-E2 Transmitter + (3) 580 EXII + radio poppers
Dave, thanks again for your kind help. My aperture sizes are as follows 18-55mm is F5.0 to F32.0
70-300mm is F4.0 to F22.0
60mm F/2.8 Macro is F2.8 to F32.0
I have found your DOF calculator very useful indeed for future reference. I have been glued to my 400D all day Dave sorting out the different calculations etc etc and my head at the moment is in a wee bit of a spin.
Today it has been quite cloudy and I have tried the three aforementioned lenses and had the ISO setting at its highest 1600 and with them all the photos across the beach, and land across the sea have been clear but somewhat dark. I just don't know how I am gonna overcome this one I am sure.
Thanks once again Dave and I will have a read at all your comments again and again until I am familiar with them all.
Kind Regards
Bob
Thanks ever so much Lynne for your kind assistance. I will order the book and the DVD and hopefully I will end up taking excellent photos like everyone else in Dgrin.
Kind Regards
Bob
You're most welcome! I think you'll find them very helpful, I know I have.
I also think you might find the 50mm 1.8 lens very useful in the depth of field practice, as your current lens lineup lacks the wide open apertures necessary to acheive a short DOF.
Add to that fact that the lens is very cheap and enables you to shoot in very low light situations without a flash, it really should be in everyone's bag.
best of luck
ETA: some people say this lens isn't the sharpest, and while it's true it is slower to auto focus in low light, it's still taking sharp pictures for me, esp. in manual focus.
lynne
50mm 1.4, 85mm 1.8, 24-70 2.8L, 35mm 1.4L, 135mm f2L
ST-E2 Transmitter + (3) 580 EXII + radio poppers
Kodak makes a nice little pocket sized reference book (http://www.amazon.com/KODAK-Pocket-Guide-Photography-Kodak/dp/0879857692) that's available in almost any camera store for under 10 bucks. It gives you some very good tips on how to set up your camera for different shots such as landscapes and fireworks shows and portraits etc...it's written in plain English and it will help give you a better understanding of how your gear actually works. It's full of useful tips and it does a wonderful job of explaing the basics of photography. Another cool thing is that it's small enough to keep in your gear bag so you can keep it close by when you need a little help.
There is no need to use all manual modes in the beginning. I use Shutter Priority a lot since I shoot lots of fast action sports where I often want to freeze the action and prevent motion blur like this - look at her pony tail and the rotors on the helicopter.
It was taken in S mode with a shutter speed of 1/500 sec. The cool thing about using the S or A modes is that you can select what is important to you, (over simplified) keeping things in focus at long distances or blurring out the background (A mode) or preventing motion blur (S mode), and then let all of the cool electronic metering gizmos in your camera select the other values needed for correct exposure.
If you have enough light, you can use both a high shutter speed and a small aperture to both stop motion and keep stuff at distance in focus all at the same time like this:
It was taken with a shutter speed of 1/500 sec at f11
The cool thing about digital is that you get instant feed back from your camera. The 1/2/3 stop adjustments are useful when you take a picture and see that it's over or under exposed. In Program mode you just select how much to adjust the exposure and the camera will select what adjustments to make for you. Modern day electronics are so cool
A quick way to see how each adjustment effects the outcome is to set up one scenario and shoot it over and over again while tweaking one little adjustment at a time. I did this when I first started and the visual feedback made it easier to undertand then all of the techie mumbo jumbo
Practice, practice, practice - it can be frustrating but, it can also be a lot fun
Hope it helps!
Mike
http://asphoto.smugmug.com
Thanks ever so much for you reply and I will definately purchase the book and the DVD for my 400D as I am sure it will help me to achieve some similar results of everyone on Dgrin.
Thanks again
Bob
Thanks ever so much Lynne I have ordered the book and the DVD and I hope I will be quite happy if I can produce excellent photos like I always see on here.
Kind Regards
Bob
http://shiningstars.smugmug.com