Questions...
Are you confusing "sharpness" in the clouds with perhaps "bringing out more detail" in the clouds, because KmH is right, clouds are not normally sharp, but they do have detail, unless they are just blanket rain clouds (stratus types) with no features?
What type of camera are you using - just curious?
Why are you using "landscape auto mode" on your camera - just curious? I would encourage you to use Aperture Priority and maybe open up half a stop or so - experiment with the settings and, if you don't know about it, check out "Exposure Compensation" if you have it.
If you have the capability, then you might try a 3 or 5 image HDR, but you will need a tripod and a remote shutter release or a timer on your camera for this.
Sometimes cloud detail can be brought out in post-processing by judicious selection of the clouds, or even just the entire sky area and then increasing the Contrast of the selection.
WesternGuy
1- Yeah, that's what I meant haha
2- I'm using a Canon Rebel T5i, with a 18-55mm lens
3- Usually I use the automatic modes in fear of not getting a good shot, and because it's much easier- it often takes lots of trial and error for me to find the correct exposure; although that can be fixed with practice... I'm not confident enough with the manual modes yet to use them in moments like this one... I will work on that though.
4- How do you do that? I've heard of it but I don't know how to do it.
Thanks for the help
1. Well, we got that cleared up.
2. Okay - a good camera for those starting out. Not so sure about the lens, but I suspect it came as as kit - camera + lens. If you are saving your pennies to buy a new lens, then you might want to consider the 24-105 or another of similar focal length. I would suggest that you not buy lenses specifically for C-sensor cameras, which is what the T5i is, as should you decide to go full frame in the future, the lenses for C-size sensors will not work on full frame cameras, but that sort of a decision just reflects my bias. My first camera was a Canon Rebel Xt. About 18 months later, I went full frame and have been that way ever since.
3. There is only one real
Manual mode on that camera and that is the one marked M. The ones marked Av and Tv can be thought of as more like semi-automatic. The Av mode, or Aperture priority is used when you set the aperture and for a given ISO (which you set) and existing lighting conditions, the camera determines the shutter speed. The Tv mode, or Shutter priority, is used when you want to set the shutter speed and for a given ISO (which you set) and lighting conditions, the camera determines the aperture. Thus, in either mode you have control over two of the three factors in the exposure - you set the Aperture or Shutter speed and the ISO and the camera determines the other one you didn't set either Aperture or Shutter speed. Here is a web site that will help you understand how all this works together -
http://improvephotography.com/photography-basics/shooting-modes/ . The references that KmH gave you are also quite good.
Personally, I take probably 90% of my images in Av mode. I use the Tv mode for those times when I need to ensure that a certain shutter speed will be used, e.g., birds in flight, animals running in a field, etc. I use the M(anual) mode mostly when I am doing macro photography and need to be very precise about my aperture and shutter speed.
The automatic modes that you are using are simply combinations of these two modes automated by some internal programming decided by some camera design engineer, based on what he/she thought the various exposures should be. There is no guarantee that the combinations that are produced with these modes will give you an optimal set of exposure parameters for any particular image. I would encourage you to move to one of the "Priority" modes for your photography.
One rule of thumb to remember is the "inverse rule". To prevent shake if you are hand-holding a camera, the shutter speed should be the inverse (more or less) of the focal length of the lens with adaption for C-sensor cameras. For example, if your are shooting at 50mm, then the minimum shutter speed should be 1/50 second for full frame and 1/(50- x 1.6) = 1/80 second for C-sensor cameras (Canon - Nikon is a bit different). If your focal length is 200mm, the the minimum speed should be 1/200 sec for full frame and 1/(200 x 1.6) = 1/320 second for C-sensor cameras. Using Av mode, then you do have to make sure that this all "matches" or you may have to adjust the ISO or aperture, or both, to achieve an adequate shutter speed. It's a learning process.
4. Selection of parts of a photograph - this is done in a variety of ways depending on the software that you have (let us know). In Lightroom there are a couple of ways to do this, depending on what you want to achieve. I probably use the Adjustment Brush for a lot of my "selecting". In Photoshop there are a number of tools for selecting "areas" or "objects" within an image. On1's Photo Suite 10 also has a lot of the "selection" capabilities that Photoshop does, but it performs some of them in different ways. I won't even begin to try and tell you how this is done in any of the products, as there are a large number of videos on YouTube and elsewhere that can explain it a lot better than I ever could.
I hope this helps a bit. There are endless resources out there on the web and I would encourage you to search them out. Regardless, I am sure if you post back here with a question, there are a large number of folks here who will try and answer them from their own experience.
WesternGuy