ISO Applications

samsplace · April 13, 2009

Hi

Is their any published information or a table, describing the applications of the available ISO settings on my new 50D:rofl . It appears their are the basic settings from 100 to 3200 as full stops, but these settings are then expandable ISO settings in 1/3 stops. It also has two additional ISO high speed setings 6400 & 12800.

Gil

Toshido · April 13, 2009

not sure of the question. Are you asking when to use what ISO setting?

if so use the lowest ISO speed you can and still get the shutter speed and aperture you need.

Unless of course you want the grain in the picture for effect.

Nikolai · April 13, 2009

Toshido wrote:

not sure of the question. Are you asking when to use what ISO setting?

if so use the lowest ISO speed you can and still get the shutter speed and aperture you need.

Unless of course you want the grain in the picture for effect.

+1

Scott_Quier · April 13, 2009

Additionally, when/if wanting to reduce grain attempt to shoot at whole stops (100, 200, 400, 800, etc).

samsplace · April 13, 2009

Toshido wrote:

not sure of the question. Are you asking when to use what ISO setting?

if so use the lowest ISO speed you can and still get the shutter speed and aperture you need.

Unless of course you want the grain in the picture for effect.

Hi
Thank you all for your responce. An example would be the normal setings would be 100,200, or 400. The ISO 100 or 200 would be for normal setings, while if you set the camera to 125 or 160 what would happen with the exposure or what would be the additional changes to the picture?

Gil

Scott_Quier · April 13, 2009

samsplace wrote:

Hi
Thank you all for your responce. An example would be the normal setings would be 100,200, or 400. The ISO 100 or 200 would be for normal setings, while if you set the camera to 125 or 160 what would happen with the exposure or what would be the additional changes to the picture?

Gil

Research, here and elsewhere, indicates that when, using a recent Canon camera, you set the ISO to

1/3 above a "full stop" setting (i.e., setting it to ISO 125), the camera will capture the image at ISO 100 and then push it in software to the ISO 125 setting. This is the same as shooting it at ISO 100 and then pushing (boosting) the exposure in post processing.
1/3 under a "full stop" (i.e., setting it to ISO 160), the camera will capture the image at the next full ISO setting (i.e., ISO 200) and then pull it that 1/3 stop before saving the data. This is the same as shooting at ISO 200 (but exposing to the right by 1/3 stop) and then adjusting the exposure in post processing.

Can't talk to what happens with a Nikon camera - I've got no experience nor have I reseached in that area.

Nikolai · April 13, 2009

Scott_Quier wrote:

Additionally, when/if wanting to reduce grain attempt to shoot at whole stops (100, 200, 400, 700, etc).

You meant 800, right?

samsplace · April 13, 2009

Nikolai wrote:

You meant 800, right?

Hi
800 is correct-Fat fingers small keys

Gil

Scott_Quier · April 13, 2009

Nikolai wrote:

You meant 800, right?

My father used to have a saying, "Listen to what I mean, not what I say." Of course, you're correct.

samsplace wrote:

Hi
800 is correct-Fat fingers small keys

Gil

Toshido · April 14, 2009

Scott_Quier wrote:

Research, here and elsewhere, indicates that when, using a recent Canon camera, you set the ISO to
1/3 above a "full stop" setting (i.e., setting it to ISO 125), the camera will capture the image at ISO 100 and then push it in software to the ISO 125 setting. This is the same as shooting it at ISO 100 and then pushing (boosting) the exposure in post processing.

1/3 under a "full stop" (i.e., setting it to ISO 160), the camera will capture the image at the next full ISO setting (i.e., ISO 200) and then pull it that 1/3 stop before saving the data. This is the same as shooting at ISO 200 (but exposing to the right by 1/3 stop) and then adjusting the exposure in post processing.

Can't talk to what happens with a Nikon camera - I've got no experience nor have I reseached in that area.

THANK YOU...

I was just about to post another thread asking why I should only use full ISO stops.

Kinda makes those intermediate stops pointless, at least if you are wiling to PP your shots at all.

Qarik · April 14, 2009

Scott_Quier wrote:

Research, here and elsewhere, indicates that when, using a recent Canon camera, you set the ISO to
1/3 above a "full stop" setting (i.e., setting it to ISO 125), the camera will capture the image at ISO 100 and then push it in software to the ISO 125 setting. This is the same as shooting it at ISO 100 and then pushing (boosting) the exposure in post processing.

1/3 under a "full stop" (i.e., setting it to ISO 160), the camera will capture the image at the next full ISO setting (i.e., ISO 200) and then pull it that 1/3 stop before saving the data. This is the same as shooting at ISO 200 (but exposing to the right by 1/3 stop) and then adjusting the exposure in post processing.

Can't talk to what happens with a Nikon camera - I've got no experience nor have I reseached in that area.

hmmm..does this mean that in between iso shots are useless in RAW?

ziggy53 · April 14, 2009

Qarik wrote:

hmmm..does this mean that in between iso shots are useless in RAW?

I am avoiding the "between" ISO settings for myself, based on the research of others. I use between f-stops and shutter speeds as appropriate.

Shark · April 15, 2009

Toshido wrote:

Are you asking when to use what ISO setting?

if so use the lowest ISO speed you can and still get the shutter speed and aperture you need.

Unless of course you want the grain in the picture for effect.

Just wondering, what does using the lowest ISO setting do for your photos? I shoot mainly at 400, unless I'm inside, then I can be upwards of 3200 ISO. What would be the difference between 400 and 100? I do alot of sports, so I'm wondering if I might get some better shots with a lower ISO setting. I know that the higher the ISO, the faster the shutter speed, and the more grain you encounter, but as far as understanding it all fully, I don't. I guess I understand just enough to get me by,,,somewhat.

ziggy53 · April 15, 2009

Shark wrote:

Just wondering, what does using the lowest ISO setting do for your photos? I shoot mainly at 400, unless I'm inside, then I can be upwards of 3200 ISO. What would be the difference between 400 and 100? I do alot of sports, so I'm wondering if I might get some better shots with a lower ISO setting. I know that the higher the ISO, the faster the shutter speed, and the more grain you encounter, but as far as understanding it all fully, I don't. I guess I understand just enough to get me by,,,somewhat.

For properly exposed images there is very little visible difference although underexposure will show a difference as will any process that increases local or global contrast (including USM treatments.) The difference can range from negligible for images with a lot of texture, which tends to "hide" visible noise, to obvious noise in images with otherwise smooth gradations and subtle tone differences.

Intended use can also affect the outcome. Larger print sizes and expanded (zoomed) digital viewing can make the problem more visible, but it may not be disagreeable depending on the subject matter and final use.

Modern dSLR cameras have remarkable ISO properties and many subjects respond very well to high-ISO treatment. Used properly, high ISOs can be a very powerful feature and allow types of photography unavailable just a few years ago.

Use higher ISOs when it is needed to allow proper f-stop and shutter combinations. Use lower ISOs when you require/desire the smoothest tonality and the lighting allows.

Khristen · April 15, 2009

50d
Along with your new Canon- they give you a packet on camera settings and other cool stuff. Check out the Canon site too. There's some pretty good info on how to work the camera.

From one 50D to another- it helped me tons with mine!

Happy shooting!

pathfinder · April 15, 2009

Qarik wrote:

hmmm..does this mean that in between iso shots are useless in RAW?

I have heard the stories on the web about intermediate ISOs giving poorer image quality, but all the ISOs are just based on amping up the signal received at the fundamental ISO of the chip. Aren't they?

Anyway, if I need an ISO higher than 100, I usually want one or two or three stops more speed, so I jump to 200, 400, 1200 or something. I just don't really see the need for the intermediate ISO steps myself.

Kind of like an amp that goes to 11, but does it in 17 discrete steps or something:D

ziggy53 · April 15, 2009

pathfinder wrote:

I have heard the stories on the web about intermediate ISOs giving poorer image quality, but all the ISOs are just based on amping up the signal received at the fundamental ISO of the chip. Aren't they?

Anyway, if I need an ISO higher than 100, I usually want one or two or three stops more speed, so I jump to 200, 400, 1200 or something. I just don't really see the need for the intermediate ISO steps myself.

Kind of like an amp that goes to 11, but does it in 17 discrete steps or something:D

Unfortunately it does not appear to be that simple:

http://forums.canonphotogroup.com/showthread.php?p=5225

samsplace · April 16, 2009

Hi All

Thank you for all the information it was very helpful.

In shooting within my new toy the ISO setting have an Auto mode which changes the ISO settings when shootings in a specific apeture or shutter speed. This appears to give a third variable in shooting.

Again thank you All

Toshido · April 16, 2009

No not really. not a third option but rather it takes the control away from the user and gives control to the camera.
Personally I think Canon failed wit the auto ISO on the 50D. The only place I would have thoguht of using it would have been manual where I could set shutter speed and aperture and let camera expose properly by changing the ISO.
In reality though the 50D sets ISO to 400 when in Manual and auto ISO, kinda pointless

In any other mode with Auto ISO you are setting one of the three variables, ISO, shutter speed, aperture, and letting the camera set the other two....

i admit I did play with it briefly in both Av and Tv modes but really don't see much of a point with it. Leaves too many variables up to the camera, hardly a step up from a green square, imo.

BobbyMarshall · April 17, 2009

I find the Auto ISO useful for situations where the lighting constantly changes and I want to give priority control to the shutter speed. For example my daughter figure skating.

Although it does seem to go on the high side most of the time, it is a helpful feature to have while trying to master the art.

For my daughters skating, Prior to my 50D I used a XTi(400D). that camera didn't have auto ISO. So what I would do was set the ISO to 400 because 800 looked pretty bad on that camera with the amount of cropping I had to do with my 17-55. then I would set the shutter and aperture in manual mode for proper exposure. even at f/2.8 I would only get about 1/4 of the shots where I could get no motion blur because I was constantly adjusting shutter for proper exposure. For this reason, Auto ISO, and better high ISO performance were some of the reasons I upgraded bodies.

Bottom line, I think auto ISO has situations where it is usefull. If I were a person who had a wide focal range of very fast glass, and never had to crop my shots, I could see why auto iso wouldnt be needed.

Nikolai · April 17, 2009

I agree. Auto ISO can be useful at times. You just need to have an understanding what you're giving up (full control over the exposure) and what you gain (less worries about exposure, more time to follow the action and frame the shot ). This stuff is great when doing certain types of PJ/event work (i.e. whenever you're pretty much taking high quality snapshots with your multi-$K gear:-), but I'd never use it for the studio environment,or serious wildlife/landscape shooting (or whenever each frame counts).

georges · April 19, 2009

Depends on Brand
When listening to general advice, you really need to understand how your particular brand of camera works for anything beyond basic functions.

For instance, Pentax K20D, lets the photographer specify the auto-ISO range. So if you want your camera to only use sensitivities between 200 and 800 (or any other combination) the camera will honor that. They've used this method for several years. I think Nikon may work in a similar way. Canon is finally starting to do something similar. Other brands my be different.

Also, many cameras have profiles, preferences, programs (they all call them someting different) that let you specify a behavior in the auto exposure modes. For instance, should the exposure system favor large apertures, fast shutter speeds, etc. These programs often alter the behavior of the auto-ISO function.

These behaviors are often not even consistent within different models from the same manufacterer. So, read the manual, listen to the advice, but be prepared to verify your results through experimentation with your camera.

ISO Applications

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