# 5D Markiii Auto Lighting Optimizer vs Highlight Tone Priority



## lenstrack26 (Oct 25, 2012)

Just received my MarkIII. Am curious if anyone has experimented with the two (apparently mutually exclusive settings) Auto Light Optimizer vs Highlight Tone Priority? I shoot exclusively in RAW. Are these two options helpful for a RAW shooter? If so, only in contrasty scenes? Would HDR be more effective, either in camera or postproduction? Thanks for sharing your experience.


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## Mt Spokane Photography (Oct 25, 2012)

Turn HTP Off! 
What it does in underexpose your image by one stop and then push it one stop during processing. This is a sure fire way to get more noise in dark areas. It might help in situations where there is a lot of bright areas in the image, because it helps to prevent overexposure. This means that even RAW images are underexposed.
ALO does not affect the RAW files, but sets a flag that DPP recognizes. You can leave it on or turn it off, it doesn't matter.


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## lenstrack26 (Oct 25, 2012)

Thanks for your input!


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## mirekti (Oct 25, 2012)

Mt Spokane Photography said:


> Turn HTP Off!
> What it does in underexpose your image by one stop and then push it one stop during processing. This is a sure fire way to get more noise in dark areas. It might help in situations where there is a lot of bright areas in the image, because it helps to prevent overexposure. This means that even RAW images are underexposed.
> ALO does not affect the RAW files, but sets a flag that DPP recognizes. You can leave it on or turn it off, it doesn't matter.



Is HTP the same as if one keept it turned off and just underexposed for one stop (shooting raw) and then brought up the shadows in Lightroom later on?


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## neuroanatomist (Oct 25, 2012)

mirekti said:


> Is HTP the same as if one keept it turned off and just underexposed for one stop (shooting raw) and then brought up the shadows in Lightroom later on?



Same idea, different execution. You'd be better off with the latter.


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## adhocphotographer (Jan 1, 2013)

I love this forum... Just searched it seeking answers to the same questions!

Thanks for the info, helped me too!


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## spinworkxroy (Jan 1, 2013)

I personally find that the sensor int he 5d3 and with newer cameras int he market are already good enough and really don't require HTP or ALO to "fix" any image..I belive with both turned off, even if it's jpg or raw, you can still recover whatever is missing or overexposed during post production…and even if you don't do post production, the newer sensors gett he scene pretty much correct int he first place…maybe in the older sensors these 2 help but not so much necessary on the 5d3…i actually shoot my 5d3 with HTP/ALO/ISO NR etc..basically everything turned OFF and i also shoot with a flat profile…works well for me.


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## RustyTheGeek (Jan 1, 2013)

neuroanatomist said:


> mirekti said:
> 
> 
> > Is HTP the same as if one keept it turned off and just underexposed for one stop (shooting raw) and then brought up the shadows in Lightroom later on?
> ...



Ditto. Been doing it this way for years when necc.


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## RustyTheGeek (Jan 1, 2013)

Great explanation of these features. I agree with all the others, I keep most of these features turned off and I try to hone my skill using Develop post work in Lightroom. Other folks with more time and skill use Photoshop. Others have promoted DXO and I may try this soon. (I installed the trial and immediately realized it didn't yet support the 6D. Waah.)


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## East Wind Photography (Jan 1, 2013)

All of those features are primarily for beginners who have not learned how to adjust exposures manually. Using them does impact frame rates and buffer capacity due to the extra processing time required (not that it takes more buffer just that the image dwells in the buffer longer and doesn't get written until after processing has completed)


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## pardus (Jan 1, 2013)

HTP works really well with video, I don't use it for stills.


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## brianleighty (Mar 25, 2013)

Wow! I've always shot with HTP on. I guess I just assumed it was better for weddings to have it since the bride is (almost) always wearing white. Very interesting. I might have to try shooting next week's wedding with it off for a change.


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## East Wind Photography (Mar 25, 2013)

It can be useful but does have an impact on drive mode frame rates. I can see where it might be more useful with video than with stills. If you do try it for a wedding, be mindful of blowing out highlights. especially if you are used to shooting with it on all the time.  It may/will increase your dynamic range.




brianleighty said:


> Wow! I've always shot with HTP on. I guess I just assumed it was better for weddings to have it since the bride is (almost) always wearing white. Very interesting. I might have to try shooting next week's wedding with it off for a change.


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## brianleighty (Mar 26, 2013)

East Wind Photography said:


> It can be useful but does have an impact on drive mode frame rates. I can see where it might be more useful with video than with stills. If you do try it for a wedding, be mindful of blowing out highlights. especially if you are used to shooting with it on all the time.  It may/will increase your dynamic range.
> 
> 
> 
> ...



What HTP increasing dynamic range? Yeah, I normally don't go over on exposure. I'm normally upping levels even when I'm shooting +2/3-1 stop of compensation. You think it'd be wise to leave one camera with it on and one with off?


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## neuroanatomist (Mar 26, 2013)

HTP increases the DR if you shoot in JPG. It underexposes by 1 stop of ISO, then lies about it in the metadata (that's why ISO 200 becomes the lowest setting - if you shoot at ISO 200 with HTP, the camera actually exposes at ISO 100). That 1-stop underexposure preserves a stop of highlights, the camera then applies a tone curve to boost everything but the highlights by 1 stop (meaning a stop more noise in the shadows). 

If you shoot RAW, leave HTP off. You then have latitude to preserve >1-stop of highlights, and can apply your own tone curve.


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## East Wind Photography (Mar 26, 2013)

If you shoot video though HTP can be a big help when the scene changes. Though shadow noise is a problem, it's a bit less obnoxious in video as is blown out highlights.



neuroanatomist said:


> HTP increases the DR if you shoot in JPG. It underexposes by 1 stop of ISO, then lies about it in the metadata (that's why ISO 200 becomes the lowest setting - if you shoot at ISO 200 with HTP, the camera actually exposes at ISO 100). That 1-stop underexposure preserves a stop of highlights, the camera then applies a tone curve to boost everything but the highlights by 1 stop (meaning a stop more noise in the shadows).
> 
> If you shoot RAW, leave HTP off. You then have latitude to preserve >1-stop of highlights, and can apply your own tone curve.


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## brianleighty (Mar 26, 2013)

neuroanatomist said:


> HTP increases the DR if you shoot in JPG. It underexposes by 1 stop of ISO, then lies about it in the metadata (that's why ISO 200 becomes the lowest setting - if you shoot at ISO 200 with HTP, the camera actually exposes at ISO 100). That 1-stop underexposure preserves a stop of highlights, the camera then applies a tone curve to boost everything but the highlights by 1 stop (meaning a stop more noise in the shadows).
> 
> If you shoot RAW, leave HTP off. You then have latitude to preserve >1-stop of highlights, and can apply your own tone curve.


Thanks neuro. I honestly never mess with curves. I've tried messing with it a few times or with the auto settings in DPP but never really liked the results. I normally just use contrast, highlight or blacks to adjust. Anyone have any suggestions on a tutorial for editing curves in DPP?


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