Canon 500d Noise - Highlight Tone Priority?
 

I am having problems with slight noise on only ISO 200 on my 500d! It's not terrible, but noticeable when you look closely. I know that there should be no noise visible at such a low ISO, unless the image is under exposed, or with a long exposure, but none of my pictures were either.

I took some photos a couple of weeks ago and had higher ISO's with less noise. So all I can put it down to, is the fact that I recently changed my settings and turned Highlight Tone Priority on, to help stop the highlights blowing out. So, I'm putting the extra noise down to this and am thinking of turning it back off.

Does anybody have any ideas on this please? :confused:

Thanks. :)

Canon say that you may get a slight increase in noise but only in the shadows. I tried it with my 7D and can not see much difference to be honest. Thing to do is turn it off again and see what happens or better still do some identical shots with and without so you can do a proper comparison.

That's a good idea, thanks Mike! :)

In my experience HTP does cause a noticable increase in noise, most obviously at lower ISO settings. Personally I have turned it off and won't be putting it back on! It's also worth switching off Auto Lighting Optimizer (ALO) as this can also cause an increase in noise.

Thanks postcardcv.

Aren't either of these setting beneficial though? I suppose you've got to weigh up the pros and cons.

To be honest I've not looked in much detail at what advantages they offer as the disadvantage of increased noise was an obvious issue so I turned them off. For me the incredible low light performance of the current cameras is fantastic and I want to maximise that in any way I can.

Thanks again postcardcv, will turn both options off. By the way, I love your bird website. The photos are fantastic!! :)

As I understand it Highlight Tone Priority underexposes by a stop and then pushes the non highlights back up a stop so it seems logical that it could cause increased noise. I never use HTP or ALO myself.

I reckon Canon put it in to help people who do not want to spend time adjusting their shots on the computer. The basic problem is that at the moment sensors do not give sufficient dynamic range so some thing has to give. I too prefer to turn the settings off and if necessary under expose the shot myself slightly with exposure compensation then bring up the shadows in Photoshop Elements if necessary just in the areas that need it. As always doing it yourself on the computer gives more control and better results.