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Photography Question 
Dale Ann Cubbage
BetterPhoto Member Since: 3/4/2004
 

ISO in the Digital World


I would like someone to explain the reason for different ISO speeds on a digital camera? I just did a wedding, which I did not get paid, it was more like an experiment for me, and I used 800 ISO. My pictures were grainy and awful! Can anyone explain to me what I did wrong? I'm sure there are other things I should have done differently, but I'm wondering if the high ISO had anything to do with it? Any info would be appreciated!


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4/5/2004 12:05:34 PM

 
Paul Michko
BetterPhoto Member Since: 3/23/2004
  Yes, the high ISO had much to do with it. As with film, the higher the ISO the more grain will be in the picture. The reason for ISO settings in digital cameras is for a trade off of grainy photos for a gain of faster shutter speeds and higher f/stops in lower light settings. If you can use a tripod, and have the exposure latitude in your camera you can force a lower ISO for less grain.


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4/6/2004 12:55:29 AM

 
Kelly Abernathy
BetterPhoto Member Since: 1/5/2004
  Hey Dale Ann - I'm dealing with this same issue. I'm trying to learn how to manipulate ISO, shutter speed and aperture to make the shot I want instead of just taking what the meter says is okay. Here's some notes I took from a couple of books I just read. Please bear with me if it seems simple, because I am a beginner.

The lower the ISO, the smoother and crisper the image. The higher the ISO the rougher or grainier the image.

Each doubling - or halving - of ISO number is equivalent to one stop of light. (e.g from ISO 100 to ISO 200 moves one stop up to a more light-sensitive setting. 100 to 800 is three stops up.)

Adjust the ISO higher to a more light-sensitive setting if there isn't enough light available for lower ISO setting. The higher the ISO, the more light sensitive, and light is what's needed to capture the image. (longer shutter speed and wider open aperture also gives more light to capture an image).

This has made a difference to me lately, because when I head out early morning to catch wildlife, I'm finding my aperture is wide open and when the meter reads correct exposure, the shutter speed is too slow to catch a moving animal at ISO200, which is the lowest my camera has. So in the next couple of days, I'm going out to experiment with higher ISOs and see what flexibility that gives me with both shutter speed and aperture - it would be nice on some of these shots to get a larger depth of field, which I haven't been able to do in the low light yet. If you're interested, I can post some of the results here to see the differences.

So what I want to do is change the ISO so that it will allow me to shoot the shutter speed and aperture combinations I want - some higher shutter speeds to catch the action and some different apertures to get the detail - or lack of it - I want. I'm still experimenting and learning what different apertures will do to a shot.

Anything indoors with a flash now still eludes me. It's beyond my abilities now - haven't gotten into studying that yet. I'd be interested in anything you learn. If I run across any good resources while I'm studying, I'll share. Take Care -K


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4/6/2004 4:46:46 AM

 
Kelly Abernathy
BetterPhoto Member Since: 1/5/2004
  Hey Dale Ann - One other idea - I don't know if you shot digital or not or if you have Photoshop or not, and remember I am SO new to PS, there may be a better way, but here's my idea. I have PS CS and there are a couple of ideas that may be helpful to you. Under filter>noise>despeckle. This will take the grain out - but then, depending on how much grain was in it could look soft focus - but then under edit>fade despeckle - you have a sliding scale on how much grain you can put back in. I've tried despeckling, unsharp masking, and fading despeckle with some decent results just putting a little grain back in. Sometimes this helps - or there may be a better way to do it that someone else knows. My knowledge of PS so far is extremely limited since I haven't had a chance to study my book yet. Talk to you soon -K


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4/6/2004 6:52:51 AM

 
Dale Ann Cubbage
BetterPhoto Member Since: 3/4/2004
  Many thanks to Paul & Kelly for taking time to offer their insight! Kelly, I think I will try that in PS, I hadn't thought of trying to remove the noise! I spent so much time trying to correct color, I wasn't thinking of that! Thanks for your notes, I too am a beginner, and your explanation actually made some sense!

Paul, I have another question for you if you get this. For a low lighting situation (church), digital camera, and using a tripod, what ISO would you have used? My camera goes as low as 100, and as high as 800. Since I wanted a little faster shutter speed to capture movement (I couldn't use flash) What kind of ratio would be a good starting point for ap/shut/iso? Can you offer anything?

Thanks again for your answers, it's starting to make sense!


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4/6/2004 9:11:59 AM

 
Dale Ann Cubbage
BetterPhoto Member Since: 3/4/2004
  K - I have no idea where I got Kelly from? Sorry, thanks to K. for all your help! I will try your suggestions and appreciate your notes!


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4/6/2004 11:06:45 AM

 
Kelly Abernathy
BetterPhoto Member Since: 1/5/2004
  Don't worry about it - K is short for Kelly. Besides, I answer to anything - some less flattering than others :) Good luck with this and the dress shot - let me know how things turn out and what you had the most luck with when adjusting it! -K


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4/6/2004 11:27:44 AM

 
Paul Michko
BetterPhoto Member Since: 3/23/2004
  I always try to go for about 1/60 sec. to ensure no camera shake. That way you can get a bit more DOF with a higher f stop. Try 200 and then 400 on ISO. See which gives you the speed you need. Again the lower you set the ISO the less noise, but for inside you need more then ISO 100 without flash.


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4/6/2004 4:46:06 PM

 
Dale Ann Cubbage
BetterPhoto Member Since: 3/4/2004
  Thank you very much Paul. I am going to try this out tomorrow night and see how it goes. I really appreciate you taking time to answer again!

da


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4/6/2004 9:26:23 PM

 
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