brightness/color correcting multiple images in batch?

Hi,

 

I shot a series of timelapse frames yesterday with my Canon Dig Rebel XTi,

1100 to be exact, from the deck of a ferry approaching Seattle. I had

intended to use manual mode with a shutter speed of 1 second and lens aperture

of F/22; I have a couple of neutral density filters on to allow for a longer

shutter speed, which lets my timelapse system work.

 

Anyway, in all of the excitement trying to deal with the ferry vibration,

tripod, wind, getting started as the ferry left the dock etc, I left the

camera in shutter priority mode, and wound up with a series of shots with some

being F/22, some at F/20, some at F/18, etc; but all at 1 second.

 

I've imported these frames into Adobe Premiere and created a timelapse movie

(you can view it here if you like http://www.youtube.com/watch?v=FyMAMN18M0Q ). The result is that there are jumpy brightness fluctuations

in the movie.

 

So, my question is, what would be some good techniques to smooth out the

brightness differences between these images? I have Photoshop Elements, GIMP,

Image Magick, and Premiere, though I'm mostly a neophyte with all of these

tools. I have a programming background, and can write a bit of batch script,

so I'm hoping for some solution that will work on the entire set of images, I

don't want to have to manually adjust each one.

 

Any suggestions on how to get started with this? I'm also pretty new to

photography, so please be gentile in your use of terminology :-)

 

Thanks!

Glenn<div></div>

Download the free Lightroom demo. Select all the images, making sure that one that you like the exposure on is the primary. Then enter the Develop module and choose "Match Total Exposures" from the Settings menu.

 

Go back to Grid and export them all, and then recreate your timelapse movie.

I should add that if you also need to correct white balance as suggested in your subject line, you can do that with the Sync tool.

OK, I tried that, and same result, so I'm guessing I didn't do it right. When I enter theh Develop module, and choose select all from the edit menu, the only clue that all of the images are selected is that there is bright text above the strip that reads "1100 selected". I then select the image I'd like as my "primary" and select Match Total Exposures. The program works for few moments and an hour glass appears... however when it is done, I look at one of the darker images, and it is still dark.

 

Perhaps I don't even know enough about the problem to state my question correctly, but I was hoping it would make sense to folks here :-)

 

I'd appreciate any general tips. Is it the brightness I need to adjust, the color? ...both? Bottom line, I'd like all of the photos in the directory to appear as though they had been taken with the same F-stop, well, that is what I think I want :-) I realize some scenes will be brighter due to more reflected light as I near the city, but I'd like to at least smooth out the cases where one photo in a series of 10 is randomly F/20 while all those around it were F/22.

Glenn,

 

Do you have Canon's Digital Photo Professional installed on your computer?

Yes, never used it before, but it is installed.

Match Total Exposures is exactly what you need. Sounds like you did it right. Did the value of the Exposure slider change in any of the images?

In DPP you create what is called a recipe. This stores all of the changes you make to an image. What you can do is load one of your images into DPP, make the changes you want and then copy the recipe to the clipboard. Next load all of the other images and then select them all. You now have an option to paste recipe to all images. Once the recipe has been applied to all images you can do a batch conversion to save the modified images as JPGs.

Mark,

 

I tried it again, then looked that the Exposure slider, yes it is changing (didn't notice before)... but in the opposite direction of what I'm wanting :-) shows what I know.

 

Perhaps my understanding of what this does is flawed, or of F-stops in general, I am new at all of this.

 

So, I used one of the brigher photos as my primary. The camera took that at F/22. This photo is mostly water, horizon, and city in the disctance. The photos I was hoping would become brighter, or at least more consistant, are those when the ferry is closer to the city. The camera jumped all over the spectrum on these and tooks some at at F/11, F/14, F/20, F22, etc.

 

After Match Total Exposure runs, the exposures on the individual frames have been adjusted some (though not in the direction I expect or want), but they are still not very even when compared to each other, and the resulting movie still has large brightness fluctuations.

 

Sorry if I'm not explaining this in terms all of you experts are used to.

 

Any more ideas?

 

Thanks again.

Zack,

Will the recipe idea work if the amount of adjustment I want on a given image is based on how bright it already is, or how bright I want it, rather than a given fixed % change? The problem I'm trying to fix is that in a line, one image might be darker than the one next to it, and I'm trying to average all of them out to a baseline brightness to eliminate jumpy lighting in the movie I'm creating from these frams.

 

Thanks

Glenn, are these raw or JPEG? If JPEG, perhaps the camera's post-processing is applying a variable amount of brightness or contrast as well. If so, I don't think you're going to find a simple automatic solution, unfortunately.

 

Mark

Glenn,

 

The recipe applies to any images that you select when it is applied. I guess you could select all of those that need the same type of correction, apply the recipe and the tweak another, apply that recipe, etc -- it's not a totally automatic process, unfortunately.