I finally had a chance to use my Ziess 21 ZE at a favorite location, Zion National Park in Utah. The first image is a closeup of a sandstone ledge. I did not apply any sharpening or color correction to these images (except the final ones shown in this post). All are converted from RAW in ACR PS CS4, saved for web at very high quality level, no sharpening.
Light here around is just lousy these november days. Just love the glowing trees against that magnificent background!
I tried my ZE21 all the way to f22. On the smaller pixels of a 450D I start to see diffraction around f13, f16 is clearly mushy, f22 bad (for what this lens is capable of at f2.8 to f11, again on a 450D).
Most surprising, however, was the deep DOF allready at f5.6. I have a feeling that landscape photographers will have to learn some new habits with the ever smaller pixels.
I didn't mean "pushing" as in "going too far", only as in "setting". Sorry if my English, which is not my mother tongue, is at fault.
As far as the existence of a f:22 setting on the lens, I believe it is pretty standard on most lenses. Yet, in most cases, it is far from optimal in terms of diffraction. So your question should be generic IMHO, rather than targeted as this one lens.
If you really need the DOF or to limit the amount of light, smaller than f/11 is usable. I still typically use f/11 as the upper limit except in those circumstances. There's not much reason to stop to f/16 if you get enough DOF at f/8-f/11, since you compromise slightly on sharpness.
Jeffrey wrote:
Landscapers use f18 to f20 all the time. I see no problems at 100%.
Does that mean f/18 to f/20 is optimum? Probably not for most landscape work especially with such a lens. Try f/8 and see if you can see a difference with the sharpness.
Live view allows very precise focusing and with most photos f/8 with the 21mm D provides more than adequate DOF.
Dan
www.danbrownphotography.com
Jeffrey wrote:
If anything past f11 is 'pushing the lens', then why does it go to f22?
The small apertures are provided so it is possible to get shots that you may not otherwise be able get (extreme sunlight, snow etc). But be aware that by using small apertures you will not be taking full advantage of the high resolution sensor and high MTF resolving lenses that you paid good money for. Images shot at very small apertures reduce the effective resolution of the sensor. It is all related to the size of the Airy disks relative to the pixel pitch. See linked reference, which has a calculator where you can calculate the effect at various apertures for a given sensor.
For the 1DsIII f16 should be useable for shots where extra DOF is needed. It is probably slightly less sharp than f11 but we can see that in the real world the shots are still superb (especially number 2). I personally wouldn't use f22 on that cam and definitely would avoid anything below f11 on high resolution crop cameras such as Canon 7D.
As others have said diffraction is a product of the camera not the lens. Don't forget these lenses can be used on older Canons as well. Smaller apertures would be much more acceptable on something like a 5D mk1, 1D, or 1Ds. Diffraction limits are decreased as pixel pitch increases.
I'm still undecided about upgrading from my 16-35mm II to the 18mm or 21mm.
Did any of you guys have the 16-35mm II prior to the 21mm? How does the IQ compare between the two? Specifically corner performance... Any input is appreciated!
I was out this morning testing a 17-35N - not a 21 prime but a kicka** Zeiss zoom just the same. I did some comparisons shots of f11 & f16 on snow laden landscape. I had never shot that lens at f16 previous - (I was wishing that f16 might somehow magically improve shooting on snow). The f11 was much sharper / clearer. I could not discern additional DOF at f16 - the foreground was reasonable & the distant objects quite diffracted. I've always found WA's best from f5.6 to f11.
Thanks for all the great input. No, I don't shoot all my landscapes at f18 to f22! But, often I am bent down capturing a scene where the foreground object is perhaps within 12" on the lens and the background mountains are a mile away. Most other times I am between f11 and f16. This is a habit that comes from using normal and longer lenses. The wide angle lenses provide a greater DOF by design, so I need to to adjust my habits. My next shoot will be further testing with wider apertures and using live view to make determinations in the field. It's a hard habit to break!
dancam wrote:
As others have said diffraction is a product of the camera not the lens. Don't forget these lenses can be used on older Canons as well. Smaller apertures would be much more acceptable on something like a 5D mk1, 1D, or 1Ds. Diffraction limits are decreased as pixel pitch increases.
Diffraction has little to do with the camera. The only difference is that with higher resolution you perceive the effects of diffraction earlier. However, the diffraction remains the same, f/16 on a 12MP and 24MP sensor will yield the same diffraction-caused softness (in print of course). The reason people complain about diffraction on higher resolution cameras is that they look at their images at 100% on the computer, and mentally compare those results with 100% images from lower resolution cameras. It's not wrong to do that though, it doesn't make a lot of sense having a high resolution sensor where you're not making use of that resolution, unless you have a burning need for that extra DOF.
