Levels, Exposure, Curves - another explanation attempt

The exposure slider in Aperture does pretty much the same as moving the right bottom sliders in Levels. One difference is that one naturally can move the right slider in levels only to the left. The exposure slider can be moved in both directions.
The brightness slider does the exactly the same, except that it acts on the left bottom control in Levels. The contrast slider acts on both the right and left control.
In general, Levels is a much more powerfull tool [than the Exposure section] but can be trickier to use (and it is easy to spoil an image by making it look anatural). Its sliders can create much more drastic changes, e.g. extremely high contrast. And by offering midtone and quartertone controls, different tonal ranges can be adjusted differently. By moving the top sliders the these controls can be moved to any point in the tonal range.
When moving the right or left slider in Levels to the start of the histogram (to create pure blacks and whites), particularly when moving them quite a bit, one often might get better results by doing this separately for the three channels than on the luminance channel.
Generally, I have the impression that Exposure/Brightness/Contrast do a better job at balancing the three colour channels than the levels adjustment set to Luminance to maintain a natural look.
Comparing with the Curve tool (in e.g. Photoshop), one can state that levels and curves do exactly the same, the top controls on the diagram in levels in Aperture are the output of curves (y-axis) and and the bottom controls in Aperture are the input of curves (x-axis). The level controls in Aperture, however, 'only' have five control sliders at the bottom and only three at the top (and none at endpoints there).
An attempt to explain why all controls do more or less the same:
Take a B&W image (that makes things easier to understand). Any global image manipulation does nothing but remap luminence values. Every lumininence value in the original image gets translated into a value in the output, e.g., adding 20 (on the scale 0-255) to all brightens an image (probably not in a very smart way). This remapping is given by a functional relationship that can be illustrated by the curve in Curve tool. But there a lot of ways to represent that functional relationship, with levels being just another one (and one that I find more intuitive).

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HT204266 if i purchase an app today can i download it on my ipad next week when i buy the ipad.....also i noticed on another purchase attempt the site would not allow me to type in my 3 digit security code? what next??

if i purchase an app today can i download it on my ipad next week when i buy the ipad.....also i noticed on another purchase attempt the site would not allow me to type in my 3 digit security code? what next??

Saw this on another post.
Applecare Senior Advisor Txx Bxxx (I have his contact info in an email he just sent) just confirmed with me that the problem people are having with the App Store not loading is an apple issue with there servers, ITS NOT YOUR IPAD so don't go restoring it! It's not happening to everyone however but they are looking into it, its really hit or miss.
In the meantime ...........
The Complete Guide to Using the iTunes Store
http://www.ilounge.com/index.php/articles/comments/the-complete-guide-to-using-t he-itunes-store/
Can't connect to the iTunes Store
http://support.apple.com/kb/TS1368
iTunes: Advanced iTunes Store troubleshooting
http://support.apple.com/kb/TS3297
Best Fixes for ‘Cannot Connect to iTunes Store’ Errors
http://ipadinsight.com/ipad-tips-tricks/best-fixes-for-cannot-connect-to-itunes- store-errors/
Try this first - Reset the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons.
This works for some users. Not sure why.
Go to Settings>General>Date and Time> Set Automatically>Off. Set the date ahead by about a year.Then see if you can connect to the store.
 Cheers, Tom

Understanding Levels and Curves

I've read some tutorials on this subject, but I'm hoping someone can help me conclude this learning chapter hopefully by a tutorial or explination on how levels and curves work and what and how to read them. So far from what I know with levels you have a white slider and a black slider I don't know how the peaks and valleys work that you see in the levels window I also don't know what the middle slider represents. As for curves I'd like to know how to use and how to read and tweak a curve what it does.

Ok that tutorial loads all the way for me. Although the business of moving values is explained Ok in there - there are a number of basic problems, and bad practice demonstrated in the tutorial, and its not one I would recommend …
1: The guy has made three moves, two Curves and a Levels - extremely destructive to the image . Where a single Curve could have done the same visually, with much less damage. In other words, he obviously doesn't realise what basic things like the endpoints of the curve do. Levels although it uses different MATH, is reproduceable in Curves very precisely. In practice, in terms of overall image EFFECT, there's really no point at all in using Levels if you know how to use Curves properly. Think of Levels as a poor mans, slightly easier to understand, Curves.
2: He has duplicated pixels instead of using Adjustment Layers, pretty thick and generates larger files.
3: He doesn't seem to know that you can place curve points automatically, and as a result doesn't explain how to do this.
I did some searching for you, trying to find something better -
http://www.youtube.com/watch?v=egwF0WWqHuE&feature=related - In 2 parts, yeah its Kloskowski, but he is explaining it quite well, especially the basic theory
http://vimeo.com/46703100 I quite liked this one, ignore all the other stuff, he's going though curves it in a way which might help it to dawn.

Exposure Curves in ACR

Using ACR (CS3), I find that I can get decent expansion of dynamic range by using one raw file and creating 3 different files from it by varying the exposure setting: 1 under-, 1 over, and 1 normal exposure. Then of course those 3 files are composited in Photoshop using the usual techniques of either masking or the HDR plug in.
But I would like to see an additional curves dialogue that affects exposure. Boosting shadows in ACR’s current tone curve dialogue does not, for example, bring out the hidden detail that really is present in the raw file. The affected areas will of course be brightned but flat, often monotone, while compositing 3 different files with differing exposure settings of that same raw file would bring out all the recorded detail.
Does Adobe have plans to make an exposure curve dialoge box?
Thanks

The Exposure slider is indeed in stops (-4 to +4 EVs) but you will find that it isn't completely equivalent to changing the exposure in the camera due to other settings in ACR also coming into play, although you may be able to find a set of brightness/contrast/black-point/toning-curve/camera-calibration that come close.

All Files (-69) Another Explanation?

Is there another explanation for (-69)?
I don't think the files are really corrupted because through everything I have done, there hasn't been any consistency in error messages until now. Plus, I started fresh with a CD and it didn't work.
I'd appreciate any advice. I'm about ready to give up on Apple.
I've already:
Done the 5 R's many times
Updated iTunes to 7.0.2 (and uninstalled/reinstalled)
Updated iPod (dock) to 2.3 (iTunes says it is updated too)
Tried an earlier version of iTunes 4.7
Used the disc that came with iPod to start over
Checked the hard drives on my computer
Stopped and started iPod services
Removed all files and added them again from from where iTunes saves them also from my back up drive
I am on Windows XP service pack 2 and the USB cable works fine for charging.

Still looking for solutions for the above question.

LEVELS? CURVES? ... EXPOSURE?

A few Photoshop generations ago, the choice was simple: curves was non destructive, but layers was. Or something like that.
Curves is certainly a welcome addition to Aperture, but I'm left wondering: is it an "either/or" or an "and" with EXPOSURE controls (RAW, obviously) and LEVELS?
I'm not one to over-tweak my images, so... any workflow tips?

I think I have to agree with most comments here too. I think it was back in V1, and was still documented in V1.5, that the bricks were placed in an order that was suggested to be the best workflow.
My own workflow always starts with the exposure brick, although it makes sense to apply cropping first if needed. I then set a base exposure correction, using the clipping overlay tool (Command+adjust) to set the black and white points using the Exposure, Recovery and Black Point adjusters as required, depending on how I want the image to look, and Brightness if needed (note that this adjuster restrains the data within the histogram scale, and does not cause clipping).
This is only a base adjustment, and simply ensures I'm working with the maximum data available. The rest just depends on how much adjustment the image needs. Well exposed images shouldn't need much else, although I've made my own version of the iPhoto 'Enhance' tool, which applies a little definition, saturation, vibrancy, and some edge sharpen - all in very subtle amounts.
I rarely use the Auto buttons though, as I find them generally too severe.
Curves I don't make much use of, as I find without experience it's much easier to make a real mess of things. The Levels tool seems more productive if you're unsure of the curves settings needed - it does a lot anyway if you enable the quarter tone adjusters.

Levels vs Curves

What is the main difference betweem levles adjustments and curves?
Booth of these adjustment layers do the same in differnt ways:
contrast corrections, midtone correction, shadow/highlight corrections, color correction.
I understand curves allows to select secific tonal points in the image.
When should levels be used instead of curves?

Levels has the advantage that you can put the screen into Threashold mode by holding down the Alt/Opt key while dragging the end sliders. This is further enhanced in that you can see which channel, or group of channels, are at clipping by the colours you see on the screen.
Curves lets you target specific tonal range, or points, and also allows complex adjustments like when the curve has multiple high and low points. Levels can't do that. I also like the larger view of the histogram you can view with Curves.

Levels, not Curves in CS6

Using CS6, try to open a curves adjustment layer...the way I have for years...levels opens. Will not correct. Have to close the app and reopen. Impossible to find on internet. What's up?

He's baaaack! My machine died, wife had terrible accident. I've not been able to do anything with my photography for months. Just got new computer, reloaded cs6. Working a large stitch. Needs lots of curve adjustments. Try curves, get levels. I had this on my old machine, have it on my new machine. First time I did curves this time, I went three curves layers before getting levels. Now get all the time. I have tried to create a curves layer every way possible...or at least the three I know of. No love. I have to shut down every time I want to make a curves layer, then get only one shot. Next curves layer is a levels.
Does no one from Adobe look at this forum?? This has to be a problem with the application. New computer...virgin...nothing other than AVG virus protection package and other adobe products...Lightroom 5 (I had 4 on my old machine). Bridge cs6. Really, someone at Adobe ought to know how to fix this. Now. I first brought this problem forward in March; it's September. Others have had it. None of the suggested "fixes"...which I appreciate...work. It's time for Adobe to speak up!
Oh yeah...I'm on a Dell XPS 8500, Intel i7, Windows 7 Ultimate, 32 gig RAM, 64 bit OS.
Peter

Are there any levels or curves in FCPX?

It looks like it would at the very least support creating a Levels effect in motion and bringing that across, but what happens is the GUI loses the histogram and the effect itself doesn't work (it just causes a blank out on the media). So is there any other way of doing this?
This seems like a bit of a draconian omission since removing the Color app which had both these and much more, right now color correction and control in FCPX seems nearly non-existant.
As much as I like many other changes to the timeline and rendering process in FCPX the gaps are large and juddering.

Hi Steve, like your hint for motion. I have both FCPX and MOTION 5, and have started to like the effects builder in Motion that appears in FCPX. But are you saying there is a method to send a FCPX project into motion for "Serious" color editing and then back to FCPX again, with the filters and adjustment options?
If so, thats a rather akward but cool solution.
Would love to see how you did that.
Cause I agree, that FCPX and color editing may be full of power, but lacking options... I mean basic basic 1-2-3 everyday video editing options like Curves, Levels, etc...
Atb Sofus

Another device attempting to share IP address?

I have an Airport Extreme that had been working fine for the past few months. 2 days ago I started to receive a message (I'm paraphrasing) " another device is attempting to share your IP address". Since then I am having problems with connectivity. At times, different devices (which had always been able to connect and concurrently with all the other of my devices) no longer connect to the AE. I've tried several resets - always with the same results. Suggestions welcome.

If they are sharing a router, then they are on the same network. Next time you see that error, write down the IP that's conflicted. Then check your computers' and router's IP addresses. If one device say, your router, has that IP address, and one notebook is trying to acquire the same IP, then you've pinpointed your conflict.

Workflow on folder level to update another list

Hi there,
I have folder structure like folder1/folder2/folder3
there are wiki pages in these folders
When I create a new wiki page in one of the folders say folder3 I want an item to be created in another list which has name same as the wiki page name.
I tried to write a workflow on site pages library(because it gave me that option only). It does not seem to workout.
Can I write a workflow to achieve this task..??
Any help will be highly appreciated...
Many thanks in advance...

Hi,
Per my knowledge, we can't set the list which has name same as the wiki page name in workflow.
So, we can use a Event Receiver to achieve your requirement.
Best Regards
TechNet Community Support
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Is anyone struggling to receive MMS on a 3gs sent on a 4S with IOS 6. I spoke to 02 today and apparently apple are working on a fix. I cant believe Apple didnt see this one coming or is it another cynical attempt to get everyone onto IOS6?

I have a 4Gs on IOS6 that wont sent MMS to a 3Gs using IOS4 something or other. I spoke to 02 today and they say there is an Apple fix on the way but there is something that can be tweaked in the meantime but she doesnt know what it is. Anyone having same problem?

By the way, may the Gods shrivel all Apple iphone software developers into a smoking crisp.

MMS on Curve (another Sprint user)

Okay, I got my blackberry 2 days ago, and I love it so much.
There is only one thing I hate, I can't pic msg, easily.
Sprint is my provider, and I've managed to just use [email protected]
Works fine, but does anyone know how I can message people with other providers?
Like Quest, Plateau, Alltel?
Would having them send a sms to my email give me it?
(I should probably try that before posting actually... )

Welcme to the Frums =
I do not believe sprint has unlocked the MMS service to allow you to send picture messages. You can send through emails. The link below is the way to send them to other carriers via email but will go to their phone.
http://supportforums.blackberry.com/rim/board/message?board.id=8300&message.id=28660#M28660
Nurse-Berry
Follow NurseBerry08 on Twitter

Exposure vs. Levels vs. Brightness/Contrast Adjustment Layers?

I have some photos that are a bit underexposed and I'm trying to brighten them up a bit and I made a Levels adjustment layer and also experimented with the Exposure adjustment layer. Are these essentially doing the same thing OR are there reasons to have a Levels adjustment layer along with an exposure one and a Brightness/Contrast one?
Thanks in advance.

The Exposure adjustment in Photoshop is primarily meant to correct tonal values of High Dynamic Range images, which are 32 bits. This command makes tonal adjustments using a linear color space or gamma instead of your image’s color space. You can use it on 8 bit or 16 bit images too, but the adjustments may seem rather drastic.
When rescuing poorly exposed 8 bit or 16 bit images, I prefer Levels or Curves because you have greater control. Brightness/Contrast, isn't something I use much.
Nancy O.

FX Factory Plugin Nattress Levels & Curves crashing Mavericks

Recently, I've reluctantly purchased FX Factory plugins - mainly because there's no other way to get Ripple Callouts and Tools (which I find really useful). I say reluctantly, because I learned a long time ago that plugins are one of the main causes of crashes in both old and new versions of FCP.
Over the past couple of days, I've been plagued with crashes and by a process of elimination, narrowed it down to the Levels and Curves plugin from FX Factory.
Those unfamiliar with plugins might think this is easily remedied by simply disabling the plugin. Not quite so. Disabling the plugin causes the clip to go "offline" - so every single clip has to have the plugin disabled or removed and of course, Levels and Curves being a colour correction plugin, the clip must be colour corrected again.
Unfortunately, I have hundreds of clips on which I've used the Levels and Curves plugin. This is a serious setback for my project. From now on, I will use the FCP X color board where possible. I say this with reservations though, because keyframing colour correction is essential in my work.
The clips are long and shot outdoors in the UK, where there's seldom a day which doesn't have huge variations in light levels.
I've found to my cost that if I use fixed exposure, the sun will come out, or clouds come over - and if I use auto-exposure, as soon as any sky appears in the shot, the footage gets adversely affected. Such are the joys of outdoor film and video production!
One of the most urgent modifications needed in FCP X is keyframing of colour correction. I realise there are workarounds, but they are messy.
I contacted FX Factory about the Levels and Curves plugin and the reply stated thus:
The authors of Levels and Curves (CC'd on this email) are working hard to identify this issue, which has appeared with OS X Mavericks. Hopefully there will be an update soon to solve the problem.
Andy

Thanks Ben.
BenB wrote:
1- Never update/upgrade mid-project.
2- Always verify all of your plugins and third party soft/hardware is compatible before any update/upgrade.
I agree in a perfect world, we'd all do this.
3- Always use an ND filter when shooting outdoors in the sun during mid-day.
How will an ND Filter prevent the light level plummeting when the sun suddenly goes behind a cloud (using manual exposure) or when the camera zooms out and the appearance of sky makes the auto-exposure darken the image?
4- Always shoot early morning and late evening when the sun is not as harsh.
Again, in a perfect world. Sometimes we don't have any choice.
Andy

Levels, Exposure, Curves - another explanation attempt

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