Best Lenses for shooting storms

[Cstok]

I am going to get the Rebel XT, but now I am finalizing on what lens. Most places offer it with the 18 - 55 lens, but I think I might get the body, and opt for the 17 - 85.

What is everyones opinion on the 18 - 55 vs. the 17 - 85?

 

[Ryan McGinnis]

I am going to get the Rebel XT, but now I am finalizing on what lens. Most places offer it with the 18 - 55 lens, but I think I might get the body, and opt for the 17 - 85.

What is everyones opinion on the 18 - 55 vs. the 17 - 85?

Go with the 17-85. For one, it has a larger range, which, if this is the only lense you're using, will be important. For another, the optical quality of this lense is much better than the 18-55, though it's still nothing to write home about.

[Broken External Image]:http://chakalakasp.cliche-host.net/review.gif

Screenshot taken from: http://tinyurl.com/4ycyj

 

[Mike Hollingshead]

LOL at the 18-55mm on that chart. I've said it on here a number of times now......stay away from that lens. I sort of feel if one is willing to spend the money on a nice dslr body they should get a nice lens for it. My old sony f707 did a better job than my rebel with that kit lens in many aspects. I'd figure out a way to get the 17-40L.

I still see the damn alternating red/green lines in some cloud/sky shots when processed at all. Most of the time I can see them with no processing done if I look hard enough.

Here is a good read and something I hope will reduce the frequency of seeing this on shots as the lens made little difference in this regard.

http://luminous-landscape.com/tutorials/bi...bit-depth.shtml

The key advantage of using a high bit image is that when you apply a Levels or Curves adjustment in Photoshop you are doing so to much more data than when you work on a low bit image. Changing the tonal range of a high bit file that has 65,536 levels Vs. a low bit file with only 256 levels means that when the data is compressed or stretched by using Levels or Curves there is more data to work with. A low bit image simply leaves gaps (the toothcomb effect as seen below) and this leads to posterization. Posterization manifests itself as abrupt jumps in colour or brightness level.

[Broken External Image]:http://luminous-landscape.com/images/hillers-comb.jpg

Instead of using just 8 bits to represent a single colour we can instead sometimes use 12 or 16 bits. A 16 bit image can handle 65,536 discrete levels of information instead of the 256 levels that an 8 bit image can. As you can imagine the increased degree of subtlety that this makes available is dramatic. And, just as an 8 bit image is actually 24 bit when we're dealing with colour, a 16 bit image is actually called 48 bit (16X3) when speaking of a 3 colour composite. A 48 bit image is capable of billions of colours.

In RAW conversion you can convert to a 16 bit file instead of the 8 bit(given your photo editing software will work with 16 bit...PS elements 2.0 will not).

If I see this problem with my images from the rebel with the 17-40L I imagine others might come across it. If you don't look for it you likely won't see it, but once you notice it it will drive you nuts and also if it shows on the screen you can bet the house it will show on a print. At least I think what I see is this same thing. Ok, sorry for the rambling. Good info on that page though.

 

[Aaron Kennedy]

Interesting survey.... I love how the 17-40mm is rated worse by people on digital than on film for distorition at the wide end (it is pretty bad). This is despite the fact that digital 1.6x bodies only cover part of the frame.

Aaron

 

[Greg Campbell]

Mike, you might try Neatimage, or one of several similar proggies. Set it to run in Y/Cr/Cb colorspace, and try to build a noise profile that catches low and very low frequency chroma noise. Apply filtration to the Cr and Cb channels, and only in the (very)low freq domain.

-Greg

 

[Glen Romine]

Interesting survey.... I love how the 17-40mm is rated worse by people on digital than on film for distorition at the wide end (it is pretty bad). This is despite the fact that digital 1.6x bodies only cover part of the frame.

Aaron

Also appears to be a trend to label same lenses 'warm' with the DSLRs. I understand the new 20d was supposed to have a default bumped up saturation setting - I wonder if that is somehow skewing the results. Don't really see how the color shift, if the lens is to be blamed, can be inconsistent between film and digital recordings.

Glen

 

[Mike Hollingshead]

Thanks Greg. I have neat image I'll have to try that and see if there is anyway to fix them.