Sigma 15mm f/2.8

[Cashmanimal 0]

http://www.sigma-photo.co.jp/english/lens/wide/15_28.htm

Just bought one. Been saving up for a while as this is a lens I have wanted to add to my collection for some time. Funny enough, I craved it for my outside photography, and it just happens to be extremely convenient that this looks like a nice lens for skydiving photography as well.

I of course read every review I could find on the internet and more about it in addition to talking to people in person (dropping triple the money for a lens than what most people pay for a digital camera is a hard commitment for a college student). It seems nobody could find any overwhelming cons about the lens. (I was also looking at the 17-35mm aspherical, but 9 out of 10 people said images were too soft, and I assumed that the remaining 1 out of the ten didn't know what they were talking about).

What sort of adjustments did you have to make? Basically, any info I can have about skydiving with this lens before I take it out would be greatly appreciated. I read many of the other forums about the lens... it appears as though I first need to remember to remove both lens caps to avoid that nasty vignetting .

Currently using an FTP, top-mount HC-30 with .45 wide angle, front-mount Rebel XT, inverted, shooting mostly AFF and coached jumps. Oh... and a Sigma 15mm (mmm... that felt good rolling off the fingers into the keyboard...finally).

Thanks in advance!

Edit for some retarded spelling.

It's all fun and until someone loses an eye... then it's just a game to find the eye

[BETO74 0]

I have that lens, check the website on my sig line for pics, no vignette, I dont know what camera youre using but a rebel ti 10.2 with that lens is more the lens works more like a 18mm instead of a 15mm.

this will be my next acquitition:
http://www.bhphotovideo.com/c/product/535763-USA/Sigma_477_101_10mm_f_2_8_EX_DC.html

http://web.mac.com/ac057a/iWeb/AC057A/H0M3.html

[dragon2 0]

Quote

I dont know what camera youre using but a rebel ti 10.2 with that lens is more the lens works more like a 18mm instead of a 15mm.

???
On a digi canon (digi rebels, 20D, 30D etc) a 15mm is a 24mm compared to 35mm, on a digi nikon (D70s, D80, D200 etc) it's 22.5mm. On no jumpable camera does it behave like 18mm.

ciel bleu,
Saskia

[sdctlc 0]

Very nice lens, I do love mine! Shooting it on a rebel XT.. Nice job on Exits and great for tandems...You should like it and depending on how much your jumping, it will get paid for pretty quick..

Scott C.

"He who Hesitates Shall Inherit the Earth!"

[Cashmanimal 0]

Quote

Quote

I dont know what camera youre using but a rebel ti 10.2 with that lens is more the lens works more like a 18mm instead of a 15mm.

???
On a digi canon (digi rebels, 20D, 30D etc) a 15mm is a 24mm compared to 35mm, on a digi nikon (D70s, D80, D200 etc) it's 22.5mm. On no jumpable camera does it behave like 18mm.

I crossed somewhere that the sensor size on the XT put the viewing angle at around 140-150 degrees, versus the 180 specc'd on the website (for the 35mm?)....

Embarrassed to admit it, but I don't actually know the viewing angle of a "normal" lens... somewhere around 50 degrees would be my guess?...

It's all fun and until someone loses an eye... then it's just a game to find the eye

[dragon2 0]

The human eye views about 45o, on a 35mm camera a 50mm lens comes closest, it used to be the standard lens for that reason. On (most) digi canons you'd need a 30mm lens to get about the same view.

generally speaking:
canon: 35mm * 1.6 = digi mm
nikon: 35mm * 1.5 = digi mm

ciel bleu,
Saskia

[DSE 3]

50mm approximates the human eye, yes. If you're shooting a Rebel (or other APSC sensor) figure approx 33mm.

**never mind, Saskia beat me to the punch

[diablopilot 2]

It's a nice lens, I had one for a while, but went back to my Sigma 14mm.

For the 15mm on a 10D (1.6 multiplier for the CCD) it has the effect of a 24mm on a 35mm camera. One difference you'll see with the multiplier is the "fish eye" effect is cropped out, as compared to the effect from a full frame camera. I found a manual setting just a bit short of Infinity to be the best for all around photography, and the subject's you'll be shooting. I did not like it so much for "over the top" bigway shooting, as it seemed wider than I liked, but great for around the outside and close in shots.

----------------------------------------------
You're not as good as you think you are. Seriously.

[Cashmanimal 0]

That's good to know, as I rarely shoot anything bigger than 4-way, still primarily outside video/stills on aff jumps... sounds like it should work out well.

It's all fun and until someone loses an eye... then it's just a game to find the eye

[Laszloimage 0]

You can set infinity on any lens.
The depth of field is coming from the combination aperture value, the focal lenght of the lens (in this case 15mm) and the size of the capturing medium (in this case a APS size or called 1.6 factor CMOS sensor).
For example if you use as low as f5 aperture on the 15mm lens (including the Sigma 15mm fish eye) and focus to 8feet everything will be in focus from 4 feet to infinity.
here's the Depth Of Field Calculator:
http://photoinf.com/Tools/Don_Fleming/Depth_Of_Filed_Calculator.html
The true issue with the Sigma 15mm lens is those nubers on the focus ring aren't accurate. If you try to use those numbers you have good chance to get soft images.
I always focus on something from the calculated distance (yes I use the tape measure!!!).
I set an object to the desired distance from the lens and using only the center point of the AF I set the focus. Then I switch back to manual focus and fix the focus ring with a tape (ugly gaffers tape)
and it works!
I took these images recently with my Rebel XT and Sigma 15mm lens (full manual settings):
http://www.laszloimage.com/Feb_2008_NEW/pages/Feb_2nd_08_MG_0212.htm

http://www.laszloimage.com/January_2008_NEW/pages/Jan_31st_08_MG_0121.htm

http://www.laszloimage.com/January_2008_NEW/pages/Jan_31st_08_MG_0135.htm

http://www.laszloimage.com/January_2008_NEW/pages/Jan_31st_08_MG_0151.htm

http://www.laszloimage.com/January_2008_NEW/pages/Jan_31st_08_MG_0166.htm

-Laszlo-

[DSE 3]

I need to point this thread to Steve Douglas (from Ken Stone's website). He and Ken claim that Sigma stems from SIGnificant MAlfunction and that they've had nothing but trouble with the lenses. We've had a few online debates, but it never struck me to send em' over here.

[sdctlc 0]

Laszlo,

Looking at the shots it looks like a flash was getting used, for sure on the last one.. Your running full manual you noted, what were the settings?

I agree on the measure, I center point focus on an object a set distance and then go to Manual Focus. For the settings I am running either AV or TV on my XT depending.. Not trying to open the debate on that issue as it is a beat horse on the forums but would be curious about the setting on the noted shots..

Thanks
Scott C.

"He who Hesitates Shall Inherit the Earth!"

[diablopilot 2]

I own and shoot 1 Canon lens and 4 Sigma lenses. Not saying Canon isn't quality stuff, but I wouldn't be using the Sigma if I didn't get great and consistent results.

----------------------------------------------
You're not as good as you think you are. Seriously.

[dragon2 0]

Meh, half my photo club has the sigma 150mm macro lens (including me), no complaints so far

ciel bleu,
Saskia

[BMFin 0]

Quote

I need to point this thread to Steve Douglas (from Ken Stone's website). He and Ken claim that Sigma stems from SIGnificant MAlfunction and that they've had nothing but trouble with the lenses. We've had a few online debates, but it never struck me to send em' over here.

I noticed it has been reported that sigma has some quality control problems.

I chose canon 10-22 over sigma 10-20 mostly becouse of these quality control issues.

For example in this review the 12-24 sigma being reviewed most likely was a bad copy. (read also the update in the end of the review)

Now the most important point is that even the folks doing these reviews (more less professinally) didnt realize that is was a bad copy. They simply thought it was how the lens is..

Its impossible to say how common these problems are but I know there has been much more talk about sigma quality control than this.. Im just too lazy to dig those out..

So most likely there are people shooting with bad copys of sigmas and havent even prehaps noticed that theres anything wrong with their lens..

EDIT: fixed the link

[Laszloimage 0]

If you're setting the focus manually and then use Tv
there's a good chance you gonna have a bunch of out focus shots. Remember in Tv mode you fixate the shutter speed and camera will adjust the exposure changing the aperture. As long as your F stop value only goes up (example you made your setting at f5 and gets brighter out side and the camera keep shooting at f8 or f11...).
But as soon as the aperture value drops below,
you can get soft images very easily.
I used a flash for every shots.
The fastest shutter I used was 1/320 the slowest was 1/200. The lowest aperture value was f7.1 the highest was f11. The lowest flash power was 1/4 the highest full on the 580EX.

[Laszloimage 0]

...well I don't know. But my Sigma 15mm seems to me a pretty dam good lens. Definitely for its price.
As I said the only screw up is the numbers on the focus ring, I cant rely on those.
Here's some example shots.
For the tandem I used my Rebel XT with the Canon 14mm L lens ($1700!)
For the AFF I used also my XT and the Sigma 15mm.
Finally a shot fro 2days ago with the 5D and the Sigma 15mm.
Check out the details when I cropped them in.
There's no difference at 8MP resolution between the Canon's $1700 and Sigmas' $370 lens exept the distortion form the fisheye effect (what I like though, just like many others incuding costumers...)
Yeh, you should probably dirrect those guys to this posting.
-Laszlo-

I don't see any "Significant Malfunction" in any of these images
www.laszloimage.com

[BMFin 0]

Lazlo !

I think your pictures are great. I have no doubt that your lens is a good copy and it performs well.

I only pointed out that some of the reviews I have read suggest that sigma has some poor copys on the market also.

I havent heard that being said about canon lenses though.

[Cashmanimal 0]

Lazlo-
Many thanks for posting those detail shots. Any doubts I had in my head (let me tell you, there were very few already) have now been removed. I can't wait.

It's all fun and until someone loses an eye... then it's just a game to find the eye

[Cashmanimal 0]

Well, the lens came in yesterday, and I couldn't be happier. I didn't get toooooo much time to play with it, but here was something I came up with after a little playing. Sorry... it's not skydiving, but I still wanted to share.

http://www.digitaldexterity.net/tempchalgal/images/1.jpg

It's all fun and until someone loses an eye... then it's just a game to find the eye