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Help with Pixelation
- Thread starter mott768
- Start date
Phyllis is right about the JPG Compression problem you're having. everytime you crop/manipulate or adjust settings the program your using is compressing your images way too much so they loose all detail.
When you're ready to save use the "File save as...." and there should be a button for Settings/advanced that will let you lessen the compression to something like 75-85 range.
What Canon is that?
When you're ready to save use the "File save as...." and there should be a button for Settings/advanced that will let you lessen the compression to something like 75-85 range.
What Canon is that?
Now we know what we are talking about. First of all, if you insist on using autofocus, then change it from 9 points into a single point. Middle point is a natural choice but if your picture composition is such that middle point is not good enough for autofocus (smooth surface or a point that should intentionally be out of focus) then select any other. Also, make sure that focus point is over something with sharp features that would allow it to autofocus.
Still, I believe that your major problem is bad light with inadequate exposure/aperture settings. When you say you are using "manual" mode, are you refering to M, Av, Tv or P setting? Stick with Av or Tv untill you fully master the techniques. Don't use M mode unless you know exactly what your speed and aperture should be BEFORE you take the shot (external light metter). Don't use P either, since you dont have real control of the speed vs aperture. P is good for generic "family vacation" shots.
Unfortunatelly any kind of widely used software today is using lossy JPEG algoriyhm, which means that no matter what kind of compression you use when saving your files, you will ALLWAYS loose some detail (mostly color). Fortunatelly, Canon has the RAW format as well, which is a) lossless and b) keeps all the additional information about the shot as well (focal points, exposure, aperture, color scheme etc). I keep both formats so I can allways get all of the details from RAW file or do quick manipulations and printing with the compressed JPEG file. If you haven't got it when you bought camera, download from Canon site Canon Zoom Browser that will allow you the rudimentary manipulation of RAW files.
I have autofocus to use single point middle. I was using AV and TV but was told to start using M, the pic of the lemon tree coral was taken in M mode and so far I think it was the best pic I have ever taken. I tried playing around with ISO speed and other settings but all I ever do is screw up the camera.
looks good Tom...I have an Xti also and at first I hate it cuz it seems like all the pics are crap but then listen to people and keep practicing and it paid off check my eye candy thread
check my eye candy threadThanks, You have some great shot's are they taken with the stock lens or a macro? I've been taking in all suggestions my biggest problem is I keep forgetting what each button on the camera is for and what changes I've made. I'm constantly resetting the camera...lol I think I need to find better software and hopefully that will help. since phyl told me to switch to M mode I did notice I'm getting clearer pic's, now I need to figure out shutter speeds and the WB.
my biggest problem is I keep forgetting what each button on the camera is for and what changes I've made. I'm constantly resetting the camera...lol I think I need to find better software and hopefully that will help. since phyl told me to switch to M mode I did notice I'm getting clearer pic's, now I need to figure out shutter speeds and the WB.
The image above had to be manipulated and re-saved.... look at the compression jaggies/artifacts. Its size is 800x533 ~25K
This one is the same image only this is the original before you manipulated it:
Looks sharp, its size is 800x533 as well but look at the file size ~155k its 6x bigger
... but it seems like you're making great progress I definetly like your last posts.
In M mode, you need to control several variables at the same time (shutter speed, aperture and the sensor speed) and set them appropriately for each individual shot. In Tv or Av mode, you preset the sensor speed (ISO), then choose what is the most significant issue (depth of field vs movement) and choose Tv or Av setting accordingly. Once you have determined that, then for each individual shot, you just vary one variable, let the camera calculate the other, and if you don't like it, you can override it and be aware of what is happening and how much you can push it and what will be sacrificed so you can try to correct that in the post-production.
Now, granted, everybody has its own ways of approaching this thing. Specially when you consider what is considered a good shot - technically good shot or artistically good shot. For example that last picture you posted is clearly technically bad (underexposed, blurred) and yet it is, from my point of view, aesthetically relatively nice and pleasing because it captures peace and solitude of the gentle coral waving in the flow of water that is metaphoric for time. I am pretty much sure that you did not take that picture with that effect on your mind and that you probably wanted something that you see in National Geographic, in which case Tv and Av modes would be best for learning the ropes. Once you master that, then, by all means, use M mode and really be creative with modifying white balance and light temperature sensitivity.
Now, granted, everybody has its own ways of approaching this thing. Specially when you consider what is considered a good shot - technically good shot or artistically good shot. For example that last picture you posted is clearly technically bad (underexposed, blurred) and yet it is, from my point of view, aesthetically relatively nice and pleasing because it captures peace and solitude of the gentle coral waving in the flow of water that is metaphoric for time.
I am pretty much sure that you did not take that picture with that effect on your mind and that you probably wanted something that you see in National Geographic, in which case Tv and Av modes would be best for learning the ropes. Once you master that, then, by all means, use M mode and really be creative with modifying white balance and light temperature sensitivity.
The first picture was taken to Photoshop and I did a "Auto Levels" followed by increasing the color saturation and finally sharpened it. If would look a lot better if it was the original file...
The second picture shows the over-compressesed picture you posted (L) and the original resized you posted (R) sandwitched by the picture I played with (M)
It was also done in Photoshop. Most of these things can prob be done in programs like Paint Shop Pro (its over-compressed)
The second picture shows the over-compressesed picture you posted (L) and the original resized you posted (R) sandwitched by the picture I played with (M)
It was also done in Photoshop. Most of these things can prob be done in programs like Paint Shop Pro (its over-compressed)
Use ISO 800 or 1600 !!!
125 is good only for direct Sun light or very strong reflectors. 125 made sense only in old film technology where the size of the grains on the film was proportional to the sensitivity. In digital technology, ISO should primarily be considered for amount of noise. While on smaller digital cameras (powershot etc) this noise is significant factor between ISO 100 and ISO 800, for larger and better cameras (like my 30D) the noise levels between ISO 200 and ISO 800 very similar (according to several sites I researched on the web). Some suggest that ISO 1600 will have the similar noise characteristics, and that performance deteriotas only with 3200, so I usually try to shoot with 800 and only if it is not enough I would go to 1600.
While I haven't seen comments on Rebel XTi's performance, I would imagine that it should have fairly good characteristics. Research the web to see how much you can push your camera.
p.s. Noise becomes comes to play with longer exposures (critical in astro photography), but for our purposes where short exposures are preferred (1/125, 1/250) it might not play such important role, and is definitively something you can play with in Photoshop.
125 is good only for direct Sun light or very strong reflectors. 125 made sense only in old film technology where the size of the grains on the film was proportional to the sensitivity. In digital technology, ISO should primarily be considered for amount of noise. While on smaller digital cameras (powershot etc) this noise is significant factor between ISO 100 and ISO 800, for larger and better cameras (like my 30D) the noise levels between ISO 200 and ISO 800 very similar (according to several sites I researched on the web). Some suggest that ISO 1600 will have the similar noise characteristics, and that performance deteriotas only with 3200, so I usually try to shoot with 800 and only if it is not enough I would go to 1600.
While I haven't seen comments on Rebel XTi's performance, I would imagine that it should have fairly good characteristics. Research the web to see how much you can push your camera.
p.s. Noise becomes comes to play with longer exposures (critical in astro photography), but for our purposes where short exposures are preferred (1/125, 1/250) it might not play such important role, and is definitively something you can play with in Photoshop.
mott768 said:
An ISO of 800-1600, while it would create a "grainier" picture, it really shouldn't allow you to "see every pixel". Can you post up a picture using 800?
Auto white balance isn't doing you any favors. You're still carrying too much blue which is why Litivm's alterations made such a difference. He pulled that blue out.
Auto white balance isn't doing you any favors. You're still carrying too much blue which is why Litivm's alterations made such a difference. He pulled that blue out.
