Noisy P65+ Files

[Chris Barrett]

I've been noticing issues lately from time to time with certain images from my P65+ being much noisier than I would expect them to be, with even the noise suppression being unable to help.

Now, I've been REALLY busy shooting, more than a bit sleep deprived and a little scattered lately so it took me longer than I care to admit to figure the problem out.

I finally noticed that the noise was occurring only on the edges of images, in particularly when I was applying liberal movements to wide lenses. As it turns out, the noise was introduced when the LCC correction (with Falloff Correction applied) attempted to adjust for vignetting. Sometimes at full strength, it's trying to compensate for up to a 2 stop loss in light and the information just isn't there in the files.

So yesterday, I just dropped the Light Falloff correction to 25%, pumped more light into the right side of the frame, and all was good again.

It makes me think that (as much as I hate putting anything in front of my lens that I should go back to using center filters on the wide lenses.

I also had one more idea to resolve these instances.... shoot a middle exposure, shoot a +2 exposure and drop that on top of the middle using the LCC exposure (with NO Falloff Correction) as a mask in Photoshop. I'm gonna have to play with that now.... but first COFFEE.

I'll cross post this to LuLA, as I think it's pretty pertinent.

C B

 

[Jack]

Hi Chris.

A few of us have been discussing this. For sure, LCC alone pumps 2 or more stops into the corners of many heavily shifted images to compensate for falloff. If you are doing a lot of that, then I think the gold-standard option is a CF plus LCC combined -- since the CF probably isn't perfect match to each lens, and then the LCC will even that out. Other advantage is you can get away with a single CF and use it on all lenses. I dislike using CF's too, but at least now we have the histo to confirm exposure . Also, I'd make sure I was ETTR with this combo too, then pull it back to desired level during conversion.

My .02,

 

[Chris Barrett]

Funny thing is, the last step in my retouching is almost always to add a little vignetting back in to increase depth. Symmetrically, of course... LoL.

Oh, what we do for our pictures.

 

[etrump]

I usually shoot a two stop over exposed image to use for the corners. You can back off the exposure even with an LCC being applied. I then use the lcc as a mask to blend it in. Seems to work for me.

 

[Jack]

Funny thing is, the last step in my retouching is almost always to add a little vignetting back in to increase depth. Symmetrically, of course... LoL.

Oh, what we do for our pictures.

:ROTFL: I often do the same -- but regardless, I want to add that creatively as desired, so no way I want it in my image to start with!

 

[thomas]

I also had one more idea to resolve these instances.... shoot a middle exposure, shoot a +2 exposure and drop that on top of the middle using the LCC exposure (with NO Falloff Correction) as a mask in Photoshop.

exactly my workflow for images with large movements (if multi exposure is possible).
Until recently I refused to use a center filter as former versions of Capture One had trouble to correct the additional lens cast introduced by a CF (going from blue to yellow). But the current version of C1 can correct this color shift. So now I will use a CF more often again.

 

[SCHWARZZEIT]

If you already know that you'll creatively want some vignetting in your image wouldn't it be better to leave some falloff in instead of introducing unnecessary noise while pushing the corners only to drop those later on anyway?

-Dominique

 

[EsbenHR]

exactly my workflow for images with large movements (if multi exposure is possible).
Until recently I refused to use a center filter as former versions of Capture One had trouble to correct the additional lens cast introduced by a CF (going from blue to yellow). But the current version of C1 can correct this color shift. So now I will use a CF more often again.

Note that this only holds for new LCC files (those that support light falloff). CaptureOne still support old LCC files in case the original shots are not available, but if you can you are better off creating new ones.

Of course, if you use a technical camera you really should take a specific LCC for each shot. You are being careful anyway (right?) so do yourself the favor.

If you already know that you'll creatively want some vignetting in your image wouldn't it be better to leave some falloff in instead of introducing unnecessary noise while pushing the corners only to drop those later on anyway?

-Dominique

This is not true: compensating for light falloff and adding a vignette will not cause a degradation if they cancel each other out. (Or: if they do it is a bug.)

This is by design and is intended to allow control: if you shift a lot, the vignette can easily be somewhere you do not desire it.

This is also nice if you have a lot of photos at different apertures and want the same look (e.g. real estate). Compensate 100% and add, say, 2 stops to all of them centered on the crop.

 

[thomas]

Of course, if you use a technical camera you really should take a specific LCC for each shot. You are being careful anyway (right?) so do yourself the favor.

Hi Esben,
yes, I always take the LCC captures for each shot.