30D 1/3-stop ISOs

Aussieroo

I have read elsewhere some think that the 1/3rd ISO stops in the 30D are "fake" and best not to be used. Is there anyone here that can shed a little light on this issue. Is there a problem in using the 1/3ISO stops. One that we would actually notice? It appears that this is in reference to RAW files. So doesn't apply to jpeg shooters.

ziggy53

It's easy enough to test. Why not rip off a few samples and share the results with us?

Thanks,

Aussieroo

ziggy53 wrote:

It's easy enough to test. Why not rip off a few samples and share the results with us?

Thanks,

Thanks Ziggy,

but I thought there might be someone more eminantly qualified than I to give a definitive answer to this. It drew quite a response on another forum I sometimes visit but didn't participate in. I feel more at "home " here and trust "the family" to come up with the answers. When it comes to "Noise" I find sometimes I have an unacceptable level of noise at 200ISO and yet at other times have quite an acceptable level at 800ISO so I figure it happens with a mind of its own so I just reduce the noise in ACR4.2 using the tricks there. But it amazes me what some people want to bag cameras out on, especially when it makes such little difference in reality. But my question still stands does anyone avoid the 1/3 incriments and only use the 100's settings? And if so , why?

ziggy53

I don't have a Canon 30D, but I use in between ISOs all the time on the Canon 1D MKII and they work fine.

As far as noise, the usual problem is underexposure at any ISO. Always expose correctly or even a little to the right, whatever the highlights allow.

Aussieroo

I don't know if I am allowed to do this here but this is the topic I was reading and wanting comment from the good people here about. Please delete this post if it is inapropiate.

http://tinyurl.com/2677tb

ziggy53

Aussieroo wrote:

I don't know if I am allowed to do this here but this is the topic I was reading and wanting comment from the good people here about. Please delete this post if it is inapropiate.

http://tinyurl.com/2677tb

Links to pertinent sites and information are fine, but thanks for asking.

I guess the first premise we are asked to accept is that IRIS is somehow correctly interpreting the RAW data, and other RAW converters are not correct. Since there is no independent corroboration of that fact (that I could find), I have to suspect the entire premise. Are we to believe that the IRIS software is the "only" software to correctly interpret the RAW data? Mightn't it be more plausible the other way around?

Anyway, it really is easy to test. Shoot a flat, slightly non-uniformly lit wall, or even the sky. Shoot it at full f stops and at 1/3rd f stops in RAW. If the premise is true that the 1/3rd f stops are interpreted as is suggested in the thread, and the way that the original poster is saying they are, there should be artifacts similar to JPG compression artifacts in the tonal gradations, jumps in tonality, if you will. It should only happen with the 1/3rd stop settings.

If you don't see those artifacts on just those settings, the assertion is probably wrong. More importantly, it will prove to you whether it matters at all. If you cannot "see" the problem, it doesn't matter even if it might be measurable.

Does that make sense?

Aussieroo

ziggy53 wrote:

...........
If you don't see those artifacts on just those settings, the assertion is probably wrong. More importantly, it will prove to you whether it matters at all. If you cannot "see" the problem, it doesn't matter even if it might be measurable.

Does that make sense?

Perfect sense thank you. I will give that a go tomorrow and see if I can put the results all on one frame and post it here. I have the feeling I won't see a lot of differentce. I tend to agree with all you say and wondered when I read that posting what ax this guy had to grind against Canon. It can get mischievious when you don't know who they are, what they shoot or whether they work for the "Oposition" and want to damage a reputation.

z_28

Aussieroo wrote:

I have read elsewhere some think that the 1/3rd ISO stops in the 30D are "fake" and best not to be used.

I set 1/3rd ISO first day after purchase and it's still there.
Sometimes is good to not read too much

Aussieroo

z_28 wrote:

...........
Sometimes is good to not read too much

Now there is a pearle of wisdom, one can put in ones pocket. Very true and sometimes too much info IS a bad thing take for example the many different ways of Editing photos. Now thats one area you can read too much.

z_28

So what do you think is - "fake" 1/3rd ISO ???

I'll read this time

Aussieroo

z_28 wrote:

So what do you think is - "fake" 1/3rd ISO ???

I'll read this time

I don't "Think" anything in this case. Just asking the question hoping for a more definitive answer. It is presented there as a weakness of the Canon 30D, seems anything to knock the "big guy" but I am of an open mind, if there is something in it I am interested to know.

z_28

You didn't post that it all about some unimportant RAW problem !!!

I'm JPEG shooter.
Next time ask your question properly, thanks.

Aussieroo

z_28 wrote:

You didn't post that it all about some unimportant RAW problem !!!

I'm JPEG shooter.
Next time ask your question properly, thanks.

Oh well EXCUSE Me! I omitted to mention RAW. May be unimportant to you but not to a lot of us.. I will alter my original post to include a reference to RAW

z_28

Aussieroo wrote:

May be unimportant to you but not to a lot of us..

Lot of you ?
Do you mean you and Ziggy ?


I rest the case

Aussieroo

z_28 wrote:

Lot of you ?
Do you mean you and Ziggy ?


I rest the case

Yeah yeah what ever! Go pick an argument with someone else, I am not biting.

ziggy53

Alright folks, keep it civil please.

Thanks.

I am not sure why the scope of the problem, if there is one, would not affect JPG images as well. All images produced by a modern digital camera start as a RAW capture. If anything, lossy compression storage technology like JPG should make the problem worse or more obvious.

Aussieroo

ziggy53 wrote:

............, All images produced by a modern digital camera start as a RAW capture. If anything, lossy compression storage technology like JPG should make the problem worse or more obvious.

Quite right Ziggy, every photo is shot in RAW, then edited according to your settings and eventually convert and save as a JPEG. Throwing out a large amount of the original RAW details. Anyway if anyone is interested in a good article called "Understanding Digital RAW Capture" you can download this 3 page pdf file from here
http://www.adobe.com/products/photoshop/pdfs/understanding_digitalrawcapture.pdf

I hope this doesn't inflame anyone, that isn't my intention. It is after all a discussion forum. I have been an exclusive JPEG shooter until recently and 99.9% of my photos so far are JPG's but in the last month I have come to understand and realise the advantage of RAW files and the controls in post editing. So I am far from "Pushing" RAW but out to learn all I can now I have started down the RAW track.