Canon 50D can't select 100ISO

[kenw]

Been awhile, but need some help. My 50d seems to be unable to select 100ISO. When you select the ISO, it goes from 200 to A (auto) and skips right over 100. All the others appear to be still available.

Seems like it would be a CF setting somewhere that changed, like enabling High ISO, but I can't find any selection that blocks 100 ISO. I've tried enable/disable High ISO specifically, no luck. Even perused my Magic Lantern guide to no avail.

Ideas?

[BeccaJ]

i believe it's the custom function that enables highlight priority or something of the sort. you have to turn that off to get to ISO 100. Had the same problem with my 7D

[juku]

On the 7D (sorry I dont have a 50D), but youd look for something similar.

C.Fn 1-2 ISO Speed Setting Increments - will provide 1/2 and 1-stop increments
0: 1/3-stop
1: 1-stop

C.Fn 1-3 ISO Expansion - expands normal mximum settings up to 12800 ISO
0: off
1: on

[Donb10]

Welcome back Ken. Missed you at the monthly meetings. Glad to see that you moved up to a 50D, not that there was anything wrong with your old 10D. You made some nice images with it.

[rbalcom]

Rebecca is right. C.FN II-3 enabled (1) limits the ISO to 200 - 3200. That is the Highlight Tone Priority function,

[shnitz]

Hmmm, I was googling some info to see what was going on, and I found some interesting threads. Apparently the 50D just interpolates the ISO for certain settings:

Question about "native ISO" on a 50d - Canon Digital Photography Forums

This would mean that it's better to shoot at rounded-off speeds, such as ISO 100, 200, etc. Off to see how my Nikon works!

[kenw]

Becca was right: CFnII: Image: Highlight tone priority, if enabled, won't allow ISO 100. Nothing in any books (Users Guide, Magic Lantern, etc) mentions this.

Since I do a lot of outdoor shots with those puffy white clouds in them, this is probably a benefit as one complaint I have always had was the lack of detail in those clouds when every thing else was considered. I was concerned about not having 100 ISO available, but now that I consider the alternative and the supposed logic behind it, I think I'm going to enable it.

Thanx to all

[rbalcom]

Originally Posted by kenw

Nothing in any books (Users Guide, Magic Lantern, etc) mentions this.

It is in the 50D Users Guide. It is in a note to the setting the ISO section. Canon puts lots of information in those notes. I learned, the hard way of course, that those notes really have to be read too.

[venchka]

Good to see you Ken!
You gotta read the book? Yikes!

[kenw]

hmmm...I'll go back, but I couldn't find it yesterday. I may have been looking in the wrong section as I was operating under the impression that was a different setting causing this.

But I did write it down in my Magic Lantern Guide for when I forget it later.... Which btw, I have been less than impressed with their newer offerings. The MLG I had for my Elan was really good and actually expanded things quite a bit. It may be because the Elan users' guide was so poorly done (many broken Engrish) that anything could be an improvement! The 50d MLG not so much. I still recommend them, but with some misgivings.

thanx

[BeccaJ]

Cool, sorry I couldnt remember the function number off the top of my head - I just happened to see a thread I knew the answer to as I was about to sign off! lol I remember googling the answer on my iphone one day when I couldnt figure it out and didnt have the guide with me!