[Photog Stuff] Rich, Kawi ...

[Okiewan]

Got the Canon 10-22mm last night, took some shots and was having real problems with it, but think I figured it out (seems obvious now), but I need some help.

If I recall, using the 10-20 Sigma, there was little effect in aperture settings; meaning, not much difference in a general wide shot, regardless of small or large aperture. Obviously, UWA is known for massive DOF, I just assumed the Canon would be the same... effected little by aperture.

The Canon, being an EF-S, (specifically made for canon's 1.6x crop sensors) is MUCH more sensitive to aperture. I kept getting OOF edges on wide shots, thinking the lens needed to be calibrated. So I did some "test" shots in the studio this morning... where I discovered the lens' ability to show shallow DOF, something I don't "think" the Sigma did, or at least not as much. Now, in a UWA I'm not saying this is better... just different. I'm guessing, because the EF-S' back lens gets closer to the sensor than a non ef-s (the sigma), there is more aperture sensitivity.

If you guys can, please take a shot at 4.5, close up to something, like this drill (something that has some front to back depth). The specs here; distance to drill, around 6"-7", 20mm, f/4.5 . The focus point was the front of the chuck.

I'd really like to see a comparison. Doable?

 

[Okiewan]

Again, at f/16:

 

[Kawidude]

Our Sigma 10-20mm is being used out on location all day today. I'll see if I can get a shot of my drill tonight with my lens at home, unless Rich provides a shot before I get to it.

I do know that I could get some pretty shallow depth of field with the Sigma. Although that was while shooting nature stuff which isn't as up-close as the drill. I'll check it out tonight and post what I shoot.

 

[Rich Rohrich]

I'll shoot a pic tonight when I get home. ;)

Until then : http://www.bhphotovideo.com/bnh/con...photo_voodooDOFapr06.jsp&O=2006newsletter.jsp

 

[Squid31]

You should find what your looking for here... http://www.dofmaster.com/dofjs.html

 

[Okiewan]

Thanks for the links...

I don't think I made clear what I'm look at.
There is a difference between the two lenses, at the same focal length, same f/, same distance to subject and from the background on the same camera. My guess is the difference is the back lens of EF-S lenses, get's closer to the sensor, changing all the DOF even at the apparent same focal length, IF, I remember how the sigma 10-20 images came out.

Make sense?

 

[Squid31]

I took a couple shots with my rebel and 18-55 and they look just like the ones you posted. I don't have a wide angle for my 1D to see if there is much difference.

 

[Okiewan]

.. the 18-55 is an EF-S as well ..

 

[Rich Rohrich]

Bob - I got called back into work last night but I'll do the test shot you asked for tonight.

 

[Okiewan]

Bob - I got called back into work last night but I'll do the test shot you asked for tonight.

Thanks.

 

[Kawidude]

I'm not sure how much help this is, considering that I don't have a studio here at home. I tried to make due with what I had but the lighting is pretty bad.

I could only get to f5.6 at 20mm on the Sigma 10-20mm. So the first one is at 5.6 and the second is at f16.

 

[Rich Rohrich]

First pic is Sigma 10-20 20mm F5.6
Second pic Nikon 18-35 23mm F4.5
Third pic Nikon 18-35 23mm F8

Focus point is the lettering on the front of the chuck in all pics.

Sorry about the lighting. I was using Sears worklights and simple reflectors and it all shifted for the middle picture . :(

 

[Okiewan]

Cool, thanks....

IMHO.... there is not as much difference in F/stop in the Sigma 10-20. No idea why?

Kawidude's shot still showed shallow DOF in both shots, even at f16.
(I'm not even saying this is bad, UWA is known for DOF and that lens kicks A$$ doing what's it's made for. (NOT product photography). I'd say the Sigma is easier to shoot than the Canon.

Rich's 10-20 shot at 5.6 was mostly in focus, but that has to do with the angle.. ie; the front of the battery is not far off the focal plane of the chuck.

This answered my question. I beieve the EF-S is more sensitive to aperture due to it's distance (back lens) from the sensor.

Thanks!

 

[Kawidude]

I was about 6"-7" away like you said in the first post.

 

[Okiewan]

In summary.. should anyone care ... :)

The Sigma is awesome. I got better shots right away with it than I did with the Canon. Color and contrast is great, maybe a tad warm, but that's subjective. Sharpness good. Images have an almost 3D look. GREAT VALUE if bought right.

The Canon is sharper at all stops, cooler color, less contrast and saturation. I prefer the warmer color of the Sigma. A little PS and it's all good though. Build quality is about equal, but the nod has to go to the Sigma.

Image quality, shooting jpg's with in camera sharpening/contrast/sat.. both are excellent.

Barrel distortion and pin cushion... Canon wins going away.

Problem with the Canon? Price. While it has the "L" glass, Canon will not label a EF-S lens with the red stripe. If you are considering going to full frame, this lens won't work. The Sigma will. Although... 10-15mm on a FF sensor would probably be useless anyway.

Ring USM (Canon) focusing is SUPER fast and silent. Nobody can touch Canon in this area. Go to any sporting event on the planet, 99% of the lenses will be "white". The Sigma however is MORE than fast .. considering we are talking about a landscape lens... how fast (AF) does it really need to be, lol.

You honestly can't go wrong with either lens. The Canon Image Quality is better right out of the camera, but costs hundreds more. You'll be happy with either.

What would I do? Tough call, but for the $200 I pretty much lost in trading lenses ... I'd get the Sigma and be done. If I were out to buy a wide angle for the first time, knowing what I do.... I'd spend the extra for the Canon 10-22.

 

[Rich Rohrich]

The more I use and learn about the Sigma 10-20, the happier I am that I bought it.

 

[Kawidude]

The more I use and learn about the Sigma 10-20, the happier I am that I bought it.

Don't hold back on any tips you might have! I really need to get out and use this lens more.

 

[Green Horn]

Thanks for the in-depth comparison, Okie. :)