Engineer Pass 4x4 Trail, Colorado, USA

[terrib]

Taken at Engineer Pass, 12,800 ft elevation. This is a 4x4 trip through old mining areas from the late 1800's.

I had some trouble with PP on these images. As I was making adjustments in the curves tool, I was unable to get the contrast that I wanted without adding graininess (?) in the sky. I'm not sure if you can see what I mean but it's where the sky goes from very deep blue to a lighter color, it looks grainy. (it shows more in #1) Is there a way to avoid this besides selecting out the sky and processing it separately? I'm still figuring out the Curves tool and included the curve diagrams here.

All C&C welcome. Thanks!

#1





#2

[dje]

Terri it's a bit hard to see the graininess or noise in the image at this size. It's probably more apparent on the original full res image. I notice you used an ISO setting of 400 which is higher than necessary for these lighting conditions (100 would have still have allowed quite a fast shutter speed). My guess is that the noise is caused by the ISO setting of 400. I suggest you apply some additional noise reduction before adjusting tonal qualities with the curves or levels adjustments. I'm not familiar with Aperture but I suspect it has noise reduction adjustment capability.

Dave

[FrankMi]

Hi Terri, both images are great but for me the second one is a real corker! Love it!

When I'm not doing a composite image, such as a panorama, I start off by pixel-peeping for grain and correct it first, if needed. Then I check for capture sharpening and again only correct if needed. Doing post processing can increase grain so it is best to be as grain-free as practical before I go any further.

If the post processing introduces unacceptable grain then I do whatever is required to control it without impacting the overall view of the image. This may be as simple as globally applying noise reduction techniques as subtle as I can get away with - or, it might include masking the offending area and applying noise reduction only there. The less detail an area has, the more aggressively you can apply noise reduction with little or no impact on the image so don't hesitate to selectively apply it if you NEED to.

For playing with any of the tools, like the Curves Adjustment, I will sometimes make a number of copies of the image and apply the techniques a number of different ways, making careful notes as to which example has which technique applied. I then compare the results from a distance, at normal viewing range and at pixel-peeping size and choose the best overall technique for the image. Once I have done this with several, particularly thorny images, I can usually predict which technique will work best for any image and start there.

I usually check curves after I have used the Threshold Adjustment to pick my White and Black points as using the eye droppers tends to get me much closer to a reasonable contrast level for my starting point.

Hope this helps!

[terrib]

...I notice you used an ISO setting of 400 which is higher than necessary for these lighting conditions (100 would have still have allowed quite a fast shutter speed). My guess is that the noise is caused by the ISO setting of 400. I suggest you apply some additional noise reduction before adjusting tonal qualities with the curves or levels adjustments. I'm not familiar with Aperture but I suspect it has noise reduction adjustment capability.

Dave

Dave, you are quite right. I have a habit of forgetting to change the ISO when I'm traveling from dark to light conditions. Thank you for reminding me!

[terrib]

Frank, thank you for the detailed reply. I will definitely go back and try this process!

[dje]

Dave, you are quite right. I have a habit of forgetting to change the ISO when I'm traveling from dark to light conditions. Thank you for reminding me!

It's easy to do Terri !! Nice shots by the way too.

Dave

[FrankMi]

Dave, you are quite right. I have a habit of forgetting to change the ISO when I'm traveling from dark to light conditions. Thank you for reminding me!

Soon you'll be remembering all these checks and soon after, you'll deliberately set the ISO much higher for all the right reasons and under the correct circumstances.

[Mike Buckley]

Terri,

Regarding your concern about the sky: When you find a particular global adjustment troublesome to a particular area of the image, simply deselect that area or select everything but that area.

I understand that the use of the Curves tool is usually considered to be a global adjustment. You can't imagine how thrilled I was to realize that it can also be used selectively. Duh...any adjustment can be used selectively! (Well, depending on the software, that's almost always true but perhaps not always true.)

I use the Curves tool selectively almost as often as I use it globally. You could instead use a Contrast slider, assuming of course that your software has such a slider. Even so, using the Curves tool to adjust contrast provides much more flexibility and control, though perhaps at the risk of losing ease of control until you master using the Curve tool.

[escaladieu]

Great compositions, just mask out the sky for the adjustments. Good work.

J

[terrib]

Right now I'm trying to master all of the capabilities of Aperture and only utilizing PSE for advanced work if absolutely necessary. Thanks for reminding me, Mike, that I can have multiple Curves adjustments. As far as I know, you can't do selections in Aperture but you can brush in (or out) adjustments. With these images the lines are fairly well defined so using the brush is definitely an option.

[Mike Buckley]

If Aperture doesn't allow you to easily make selections, I highly recommend that you not spend the time required to master it. The quality of your photography has already advanced to the point that you shouldn't be held back by such limitations. If you're concerned about cost, I know of a highly recognized Norwegian pro who utilizes GIMP, which is free, as his primary editor. Even PSE that you've already paid for does a reasonably good job of making selections a relatively easy task.

[Geoff F]

Terri, just a couple of thoughts.

When I get problems with Curves, for example an over blue sea, I switch the Blend Mode to Luminosity so you are working more with brightness than colour/saturation. Those can be adjusted with separate Curves Layers.

Sharpening problems, like excessive noise sometimes works better by sharpening on a duplicate layer which is switched to Luminosity.

And of course, as Mike mentioned, adding a mask to an adjustment layer enables you to selectively apply the effect.

Secondly, you appear to be adjusting Curves in straight lines which defeats their chief purpose, and name. I'm always reluctant to move the shadows end point as this can exaggerate noise etc.

I prefer to bend the lines to suit but keep the bottom shadow point and often the top highlight point unmoved.

[terrib]

...

Secondly, you appear to be adjusting Curves in straight lines which defeats their chief purpose, and name. I'm always reluctant to move the shadows end point as this can exaggerate noise etc.

I prefer to bend the lines to suit but keep the bottom shadow point and often the top highlight point unmoved.

Geoff, Thank you for the information. So are you saying that the black slider usually stays all the way to the left? My process is that I will try to make adjustments on my own but if I'm having trouble with a particular curve I will many times hit the Auto button to get a starting point and then I'll adjust from there. Most of the time, I will end up moving the sliders back out to the sides because Auto almost always introduces blown highlights and deep shadows. And if the histogram is like this one with the starting points well away from the sides, it seems that introducing another point on the diagonal above where the histogram starts will keep the darks and lights from going too far but still allow me to add contrast to the mid tones. So my usual way of dealing with Curves may be closer to what you do. But on these particular shots, moving the sliders back to the sides didn't seem to make a difference so I left them alone. Perhaps I'm not looking closely enough.

[Mike Buckley]

Terri,

I'm gong to offer an opinion that perhaps differs from Geoff's, depending on what he meant: I have no problem moderately adjusting the black slider to the right or the white slider to the left, as I see no increase in noise. Once I get my black and white points where I want them, I then adjust the curve.

However, if Geoff is saying that he prefers not to drag the lower end point of the diagonal line upward or drag the upper end point downward, I completely agree with him in all but the rarest circumstances. I do occasionally drag the upper end point downward when that's the only way to get rid of blown highlights that indeed can be retrieved.

Keep in mind that any time you move the black slider to the right and/or the white slider to the left, you are also increasing the contrast. That's because any time any part of the curve becomes more vertical, contrast is increased. Moving the outer sliders inward results in a more vertical line.

Naturally, in scenes such as these, you can then drag the lower third of the curve downward and the upper third of the curve upward (forming a classic S-curve) to render the center part of the curve more vertical and, thus, increase the contrast in the mid-tones. Caveat: Not all scenes are improved by any particular adjustment. Sometimes even the classic S-curve is actually detrimental rather than helpful.

Remember that the Curves tool is very effective when applying it to a selection, not just applying it to a global adjustment. However, I recommend doing the global adjustment first and following up if needed with local adjustments.

[Geoff F]

Yes, as Mike said, an S shape curve, in some form, is what I do most often. Although the highlights can sometimes be slightly increased as well. Giving a 'distorted S'.

If I'm uncertain of how to adjust, I do sometimes try the Auto setting to give me a few ideas, then cancel it and 'do it my way'.