Adusting levels in PSCS6 - doing it wrong?

[new_bee]

<p>I took a class many years ago and learned how to adjust levels in Photoshop. I haven't done this in a while and may have skipped some steps. I'd like to know if what I am doing to adjust levels is incorrect. I am using Photoshop CS6 to edit my photos.<br>

1- I open my RAW file in PS<br>

2- I adjust levels by going to Image > Adjustments > Levels<br>

3- I adjust each channel separately<br>

4- I save the image as a JPEG<br>

<br />Am I missing something here? I did a resent search and found a similar procedure but before the levels were adjusted a layer was created. Does that step make a big difference? Will my image quality suffer if I don't make a new layer before adjusting levels?<br>

I'd appreciate any enlightenment on this subject. </p>

 

[djthomas]

<p>Hi--you actually do not want to adjust the layer directly, but instead create an adjustment layer -- in this instance you can do this directly above the layer you want to have the changes show up on. This way you don't adversely effect the original image (non-destructive editing). While in the layers palette, click on the layer you want to apply your level changes to and then move to the bottom of the layers palette and you'll see a series of icons (forgive me--I'm doing this from memory) -- look for the circle that is half colored in (like a half moon), click on it, and a series of options will appear. Select Levels and you can adjust your sliders as needed. There are a lot of other things you do from here (creating masks, work with blending modes, etc.) but this way you play with the sliders even after you've finished your image and want to go back an tweak things later. If you apply 'level' changes directly to the image and save it, you are pretty much stuck with what you've created (unless you have a back-up of the original file somewhere).</p>

<p>You'll notice that there are a lot of options you can use on an adjustment layer as well--not just 'Levels' -- all non-destructive. </p>

<p>Hope this helps.</p>

[Spearhead]

<p>Can you post a before and after? That would help to tell you what might work better. I rarely adjust individual channels with levels, I usually do that with curves. I use levels sometimes to move the overall exposure and white/black points, that's it.</p>

[new_bee]

<p>Hi David. Thanks for your comments. <br /><br />When you spoke about not creating a layer first you stated, "...adversely effect the original image (non-destructive editing)". If I did not create a layer first - does my overall image quality suffer? If so, how?<br>

I'm only asking because I have edited too many images without creating a layer first.</p>

[blumesan]

<p>Making adjustments (levels or any other tool) directly on the image does not adversely affect the image quality. However doing so deprives you of the opportunity to go back, at some later stage in the editing process, and re-adjust (fine tune) the adjustment. <br>

I agree with Jeff; adjusting individual channel levels is not a recommended procedure.</p>

[ellis_vener_photography]

Using layers when you make image adjustments allows to you go back and revisit the change you made without have by

to undo what you had done afterward. Using layers also lets you use a mask on the layer to limit what area of the image

you want to change, use different blend modes, and group some layers together.

 

I like to save the layered document as the master and when satisfied make a duplicate with the layers flattened.

 

Since you are interested in working with others the individual color channels, to take that way of working to the next level,

check out Lee Varis' "10 channel color workflow" videos on Vimeo.

[djthomas]

<p>New Bee-- when you open an image (a jpeg or RAW file) in Photoshop, it is placed on its own layer, typical called Background. Because I can get overly paranoid about things, I usually duplicate this layer and keep the background layer locked and turned off (it's one of my [many] quirks). If all I want to do is adjust the levels to this image, I create an adjustment layer--by clicking on the icon I mentioned above, it will automatically create a new layer above your image and open a levels adjustment box where you can move the sliders which appear to adjust the image below this layer. I say appear because as an adjustment layer it actually doesn't touch your image, but has the same impact as if it did. It's sorta like putting sunglasses on -- it makes it look like the sun isn't as bright and the glare is reduced, and you know that your glasses don't actually change the sky, and if you lift those glasses, things will appear "normal" again. So, if you turn the adjustment layer off by clicking on the little 'eye' icon, your image below will appear as it did before you adjusted it. Also, with an adjustment layer, you can always go back to that layer and re-open the dialog/function box and refine/change your adjustments--again, all without ever modifying the original image itself.</p>

<p>The question I think you are raising though when you mention channels is that the 'Levels' function is perhaps not your best option to use as it has some limitations in what it will produce. Typically, when you get into channels discussions you are better off using a 'Curves' adjustment layer. Admittedly it is a bit more complicated than Levels, but once you understand how it works and what it can do, you may be more satisfied with the results you can get.</p>

<p>As far as your image quality, opening an image in Photoshop alone will not diminish the quality of the image--what you do to the image once you are in the application is another matter. The great thing about this application is that you can pretty much do everything you can think of in the application without ever touching the original at all. Your options while saving a final image can have an impact on the quality: as a native PSD (Photoshop format) or TIFF format, you will have your highest quality. As a jpeg, you can lose some of the quality depending on your settings when saving as a jpeg. And again, depending on your intended use--say putting out on the web, or on your FB page, jpeg may be fine. File sizes are generally smaller, faster to display, etc. But if it is an image that you want to keep--or possibly edit again, stay with PSD or TIFF. I usually end up with a jpeg version which is essentially the same as a 'flattened' file as Ellis mentioned--and I have my PSD/TIFF files saved as well.</p>

[q.g._de_bakker]

Adding layers inflates the file, and isn't always necessary. If adjusting levels is what the image needs, you can adjust levels and end up with a better image than you started out with, so no reason to want to go back.<br>It is 'best practice' anyway to keep the original file and store any edited version as a separate, new file.

[Spearhead]

<blockquote>

<p>Adding layers inflates the file</p>

</blockquote>

<p> <br>

This isn't true for adjustment layers, which is what people are recommending.</p>

[Spearhead]

<blockquote>

<p>in case you are doing any color alterations. </p>

</blockquote>

<p> <br>

This is why a before/after upload would be very useful. It's not clear what is being done.<br>

<br>

</p>

[peter_mounier]

<blockquote>

<p>Adding layers inflates the file</p>

</blockquote>

<p> </p>

<blockquote>

<p>This isn't true for adjustment layers, which is what people are recommending.</p>

</blockquote>

<p> <br>

Adding layers does indeed inflate the file. I just tested that and the file doubled in size when I added adjustment layers. No masks, just a Curve layer and a Hue/Saturation layer without adjustments. I started with an unlayered tiff file and added the adjustment layers, then saved the layered file as a tiff. I also saved it as a psd file and they are both twice the size of the unaltered tiff.<br>

I'm still using CS5, but if that has changed in later versions it would be news to me.</p>

[Spearhead]

<p>You're right, however, adjustment layers after the first one do not change file size much.</p>

[q.g._de_bakker]

I didn't mean that the file size grows (which happens), but that with growing numbers of layers it gets harder to navigate through the different versions/states i.e.layers contained in it. If every try at adjusting something needs an extra layer, the number of layers gets large fairly rapidly.<br>But YMMV. Not all editing involves multiple steps. And you could create groups to make keeping tracks of layers easier. Etc.<br><br>Yet, when an image needs a certain adjustment, and you can apply that the best way possible, there is not much (if anything) that would make it better practice to keep that adjustment reversible. When destructive editing destroys something you do not want, results in something you do want, hurray for destructive editing!

[djthomas]

<p>The OP asked about image quality, not file size as the issue; besides, going from an initial RAW file to a jpeg of the same dimensions is pretty much going to produce a smaller sized file anyway. If people want to create and save their layered files, disk space (removable or otherwise) is inexpensive. Personally, I save all my RAW files which takes up the most space and only select a few that I spend a lot of time on in Photoshop where I certainly want to save my layered file.</p>

<p>Regarding image quality, of the file types mentioned in this discussion, RAW, PSD, TIFF and JPEG, generally the one with the poorest quality is JPEG. So jumping from RAW to JPEG through Photoshop where the OP has modified the RAW file and saved the output as a JPEG there would be some loss of overall quality. Is it a significant loss, or even noticeable? Not necessarily--again, depending on what the end game is. One way to get a quick look at the quality variable is to create your image and perform a 'Save for Web' option and compare the Photoshop image to the three possible JPEG options where you can set the quality level. A 90 to 100% setting can sometimes be difficult to distinguish from the native PS file whereas a 40% setting can look pretty bad--especially in areas of fine detail.</p>

[q.g._de_bakker]

Quite right. JPEG is one of the worst. Still quite useable, when used judiciously.<br>But the OP asked <i>"Will my image quality suffer if I don't make a new layer before adjusting levels?"</i> ;-)

[lenny_eiger]

<blockquote>

<p>I took a class many years ago and learned how to adjust levels in Photoshop. I haven't done this in a while and may have skipped some steps. </p>

 

</blockquote>

<p>I am a professional printer. First, you will do yourself a huge favor if you forget that Levels exist. This is a "sledgehammer-level" tool that more often than not makes a mess. Curves are a much finer tool, they keep everything else in the image in relationship with what you are doing. Hue/Saturation is good too, but learning one's curves is the first step towards getting a handle on PhotoShop.</p>

<p>Second, I can't imagine any other way than with adjustment layers. If you make a change that goes too far, you can just adjust it back. (Without an adjustment layer, doing this will degrade your image.) Further, adjustment layers offer the ability of working with masks. These are specific areas that you select to make changes to. You can add as many layers as you want, but 1-5 of them are usually plenty. There are lots of great masking techniques, but you didn't ask about that...</p>

<p>I save in psd unless its bigger than 500mb or so, then I use psb (Large Document Format). The only time I use jpg is to put an image up on the web or to send it too someone...</p>

[q.g._de_bakker]

Just so it doesn't create confusion similar to the one about needing layers to adjust levels: masking techniques can be used whether you use adjustment layers or not, do not require adjustment layers.<br><br>I agree that PS's native PSD format would be the most logical choice to use for images that you still want to work on. For sharing, TIFF is better, because a more 'universal' format (that still allows for full quality images, with layers if required). For end use JPG is fine, provided it is created with caution, without too much compression.<br>I leave the choice between PSD and PSB to PS. If files grow too big, PS cannot use PSD and PSB is the only PS-own option.

[lenny_eiger]

<p>I generally start with files that are a gig or more. (I have a drum scanner.) The file size does not double with adjustment layers, not even the first one, or it would be unusable. It adds maybe 10-20%. I don't doubt that it might add more at much smaller sizes.</p>

<p>Duplicating the background layer will definitely double the size of the file, however. I don't do it unless a High Pass filter is required, which is rare.</p>

<p>Frankly, with all due respect, it is not reasonable to make adjustments that you can't back off of. I think anyone with experience, certainly anyone who prints for a living will tell you that adjustment layers are a must.</p>

[q.g._de_bakker]

Let's agree to disagree on that last bit, Lenny.<br>Myself, i think that if you know what to change, why and into what, you should just do it. I don't see anything wrong wrong or unprofessional with offering a product the way you, as skilled and confident professional and author of the image, decide it has to be.<br>But i will admit that i too hedge my bets by retaining the original of any file i edit.

[lenny_eiger]

<p>I am happy to disagree politely. Too much of the other on these forums.</p>

<p>When someone asks me to make a print for them, its their image. If they want me to make it a little more green, I am happy to do so. I don't throw out anything that a client sends me. If I make it greener without an adjustment layer, and its too much, backing off by making it more magenta will hurt the image. Do it enough and the image will be mush. By contrast, an adjustment layer can be corrected all day long back and forth and it won't affect the image. And if you don't like it you can throw the whole thing out....</p>

<p>I don't ever want to have to revert to a backup after 4 hours or more of work, spotting, masking, correcting one thing or another. There are always multiple things going on, multiple issues to address. A backup is just not enough... and adjustment layers fit the bill quite logically.</p>

<p>If you tell me a 3 Gig file went to 6 Gig, I would be concerned as well... however, its never happened to me. If the image size is doubling on a decent-sized image, then something is going wrong...</p>

[q.g._de_bakker]

The thing then appears to be that there are two people deciding what should be done. A communication thing, with one not quite knowing whether what he/she decides to do is the correct translation of what that other person asked to do.<br><br>Anyway, i wanted to point something else out, it being that if you first adjust towards green and don't like it, you then do not go on and do a second adjust back to magenta again, but undo the first, green adjustment. States are kept by PS and can be returned to also without adjustment layers. But yes, only as long as the edit session is open.

[lenny_eiger]

<p>You are correct, if you have the change in the History states then you can reverse it. Of course you lose everything after that point... </p>

<p>Adjustment layers are a great thing. Masking in conjunction with adjustment layers makes PhotoShop reasonable, and is the main reason to use it over other solutions, IMO.</p>

<p>It seems to me like arguing for one's limitations. I just don't see a reason not to use a valuable tool.</p>

[Bill C]

Lenny, I think that you do a special sort of work - the higher end of the trade. I don't see too many wedding shooters coming to you with

upwards of a dozen rolls or film, knowing that there will be hours of labor in every image.

 

I have background in the high volume part of the business. Comparing the two types is a bit like comparing the operations of Rolls Royce to

Ford or Chevrolet. High volume labs used software like Kodak's DP2, not Photoshop. Or perhaps Photoshop is reserved for certain images

that for some reason need extensive correction. (We actually had several dozen people running Photoshop for restoration work, but we

were running more production work than most people here can probably imagine.) Now our work was nothing like Lenny's, where he tries to

get near the best that he can. Our goal was to get within a certain tolerance range, do dust spotting, and get the work shipped. Different

sorts of things.

 

I don't know that it's right to say that using layers is "correct" or not. It's more a matter of what works for you (given your product aims) and

how efficient it is. Although I guess if you consider yourself an artist, you may not even care about the efficiency.

[q.g._de_bakker]

I do see the merit of adjustment layers, but that is not that without you cannot get the best we can.<br>Maybe a non-PS example: if you find a framed picture not hanging level on your wall, you give it a push and make it hang level. No need to first mark the angled position so you can return to it. You do not want to return to it. The problem is that it is not level, so you make it so it is level and move on happily.

[lenny_eiger]

<p>Bill C, I can certainly appreciate this. I have worked both sides of the street. I've worked in printing labs and even worked for a wedding photographer who paid me 10 cents a print, for 5x7's he could put into booklets to show his clients. I made 60 good prints an hour... with a little processor and two negative carriers to swap in and out.... In the '70's that was double the minimum wage and it was a little extra cash for me...</p>

<p>Certainly Levels can make a change. However, any change you can make with Levels you can make with Curves. The Curve action will be better, result in a better print. I realize that's a blanket statement but its at least 90% true. One will also learn to use Curves, they will get more and more intuitive and that is a very valuable thing, IMO.</p>

<p>Q.G. - I often return to prints. Often years later my aesthetics have changed, and I want to print it again with a different feel. I usually print something then leave it out where I can see it. It takes me time to understand things at a certain level. In the morning I might make one more change, or decide that I like it the way i've done it. I need to be able to go back to it. That may be different for you.... and there are many kinds of printing, from the kind that Bill C is speaking about to everything in the middle...</p>