Guide on ISO-speeds, suggestions anyone?

[kasperkjaerphoto]

Hi Photo Forum

I'm currently writting a guide on ISO-speeds for my blog, and I was wondering if anybody thinks anything is missing. Subjects covered:
- Grainy images at high ISO-speeds.
- High memory consumption at high ISO-speeds.
- High battery consumption at high ISO-speeds.
- Exposure time at different ISO-speeds.
- Picture examples of what the different speeds do to the image.

I will post a link, when I am done writting the guide.
I am writting it because I think that the guides already online, are lacking in pictures comparing the different speeds and many beginner camera users are confused and thinks that shooting at ISO1600 all the time is the best, because it takes up the most space and space=quality.

Please comment and give advice.

 

[Formatted]

- High memory consumption at high ISO-speeds.
- High battery consumption at high ISO-speeds.

Are these even true?

 

[rufus5150]

High-ISO images take more drive space (3200ISO images on my 7D are about 5meg more than ISO 100).

The battery life one is interesting. In theory, I can see why that might be the case...

 

[Josh66]

- High memory consumption at high ISO-speeds.
- High battery consumption at high ISO-speeds.

Are these even true?

Yes.

My high ISO shots are noticeably larger than low ISO ones. Take a look at the properties of your pictures...

The battery part, I don't know and have no way to test it...

I would think that it's true though, since the camera is doing more work, and you would think using more energy as a result.

 

[AverageJoe]

So, a higher ISO value may give you a better exposure capturing more detail which in turn could mean a larger file size? Is that the line of thinking?

 

[Josh66]

It's larger because more is being done to it.

It's amplified from the base ISO - that adds 'junk' to the file, which makes it bigger.

 

[AverageJoe]

It's amplified from the base ISO - that adds 'junk' to the file, which makes it bigger.

"Junk" being noise/artifacts?

 

[Josh66]

It's amplified from the base ISO - that adds 'junk' to the file, which makes it bigger.

"Junk" being noise/artifacts?

Just extra data that isn't there for base ISO images.

High ISO on digital is just the base ISO, amplified. When you do that, it's going to require more data...


'Junk' is just 'extra stuff'. I'm not a programmer or engineer, so that's about as specific as I can get.

 

[TheEugeneKam]

Well Electrical engeneering 101. The higher iso, the more the power consumption to an extent is true. The way digital camera's sensor gets higher sensetivity is by sending more power to the sensor. So there is the higher power consumption in theory. Sensors in cameras are analog, so the higher the power sent to the sensor the more distortion is created, hense the high ISO grain. So looking here at this the higher battery consumption makes sense.
This however is very hard to prove fully and is absolutly situational. Therefore i would exclude this section. Now looking at this again in a different situation. comparing the high power consumption of 1600 ISO to 100 ISO, we see that the sensor has to operate (too lazy for math) for alot longer, and record the image for longer period of time, the camera processor has to compile more data, therefore it will use more power.

This requires some math and a very good understanding of camera processor and the sensor, therefore it is not worth proving and is of no use as it will be different from camera to camera and single result not always hold true generally, seeing as there are smaller sensors with high pixel desity and bigger sensors with the same megapixel count with less pixel density. Technically this is highly theoretical and useless information to almost every consumer, the only people that would care about this are the engeneers of the cameras.
/end rant

 

[PASM]

More gain .. more power.

The battery life one is interesting. In theory, I can see why that might be the case...

 

[kasperkjaerphoto]

Seems like the guide is a good idea, many people obviously doesn't know that the high ISO-speed causes grain and large files.
The battery consumption is from personal experience, I have noticed that my battery drains a lot faster when I am photographing at higher speeds.
Thank you for your feedback everybody.

 

[Overread14 2]

Personally I would greatly underplay the filesize and battery consumption aspects of this guide. Almost add them as small trinkets of info rather than a mainstay in the differences of high ISOs. This is because the differences are both marginal and not important at the time of shooting to a photographer.
They don't need to know that their camera is using a tiny bit more power or less power because so many other functions are doing the same thing all the time (eg viewing previews - menu controls etc..). So on that score they don't need to factor this as part of their shooting methodology.
Similarly whilst file size can be an important consideration for some the differences should be marginal to a photographer who would expect to have larger storage capacity for photos in their computer. Further you can't actively predict the values so it is again another concern that a photographer does not need to worry about when in the field and having to make the choice between high and low ISO.

 

[kasperkjaerphoto]

Personally I would greatly underplay the filesize and battery consumption aspects of this guide. Almost add them as small trinkets of info rather than a mainstay in the differences of high ISOs. This is because the differences are both marginal and not important at the time of shooting to a photographer.
They don't need to know that their camera is using a tiny bit more power or less power because so many other functions are doing the same thing all the time (eg viewing previews - menu controls etc..). So on that score they don't need to factor this as part of their shooting methodology.
Similarly whilst file size can be an important consideration for some the differences should be marginal to a photographer who would expect to have larger storage capacity for photos in their computer. Further you can't actively predict the values so it is again another concern that a photographer does not need to worry about when in the field and having to make the choice between high and low ISO.

My main focus point is on image quality, but an ISO1600 picture is nearly twice the size of an ISO100, so while it might not be important to the profesional photographer, to an amateur photographer it could mean not having enough room on the memory card.

 

[Overread14 2]

My main focus point is on image quality, but an ISO1600 picture is nearly twice the size of an ISO100, so while it might not be important to the profesional photographer, to an amateur photographer it could mean not having enough room on the memory card.

true but if they can't expose the shot correctly at ISO 100 surly that is going to introduce more noise data which bumps up the file size again.

Also I don't know about other cameras, but when it comes to file space most only display a rough guildline as to the number of photos as person can take - actual file storage space used is only shown (on mine) when you go to the formate memory card menu option (not something you want to be hovering over just after taking a whole cards worth of shots ). I just feel you're going for a level of detail which is factually accurate, but which in practice is not something that is practical for the photographer to be concerned about

 

[kasperkjaerphoto]

My main focus point is on image quality, but an ISO1600 picture is nearly twice the size of an ISO100, so while it might not be important to the profesional photographer, to an amateur photographer it could mean not having enough room on the memory card.

true but if they can't expose the shot correctly at ISO 100 surly that is going to introduce more noise data which bumps up the file size again.

Also I don't know about other cameras, but when it comes to file space most only display a rough guildline as to the number of photos as person can take - actual file storage space used is only shown (on mine) when you go to the formate memory card menu option (not something you want to be hovering over just after taking a whole cards worth of shots ). I just feel you're going for a level of detail which is factually accurate, but which in practice is not something that is practical for the photographer to be concerned about

There is less noise at ISO100, the only downside is the longer exposure time, this does not take up space, but it increases the risk of camera shake.

I am not talking about the estimated space, I'm talking about the actual file size, in my tests an average increase of 90% is to be expected when going from ISO100 to ISO1600 when taking photos in an enviroment where ISO200 or ISO400 would be recommended.