Sigma 10-20mm F4-5.6 DC HSM driving me mad

maverick75 wrote in post #16633420
Where are you focusing with your AF point?

like in the foreground, middle or background?

The in focus parts looks really good and sharp.

Not really sure where i should be focusing with this lens to be honest. In most instances i just focus right down the center of the image. I have had more practice with my other lenses and i can focus on specific objects and ignore the rest but with this UWA lens i am not really sure where my focus points should be. In most instances it's the background. Also, i am struggling to understand what it means to focus at infinity for these shots. Is it the same as focusing at the farthest object you see?

MalVeauX wrote in post #16633532
Heya,

Wide open, it's not going to be as sharp as when stopped down. Focus to infinity. I'm not sure how you achieved focus, but overall, it looks fine to me, but looks a touch soft around the edges (normal) with distortion, and the center areas look the sharpest. If you did not, I would recommend you focus to infinity manually. Do not use autofocus unless you're trying to focus on something in the foreground specifically. For landscape, big scenes, etc, you want to stop down to F8 or F11, manually focus to infinity, and you're good to go.

Looking at all your images, the beach ones, the trees are soft. But other things are sharp. This tells me it's not the lens, but rather, your focusing and the fact that it's wide open aperture, not stopped down.

Looking at the stadium, the center stuff is sharp (antennae, edges of building, etc), but the peripheral stuff is softer. That's probably the lens a bit and that's due to distortion and all, maybe. I'm not positive on this one.

Did you use autofocus, or did you manually focus to infinity? I would suggest you use LiveView, magnification 10x, and manually focus on something distant (tree line, building edge) for sharpness. Call that infinity for your shots. And leave it set to manual so autofocus doesn't change it. If it's still soft, pitch the lens, get something sharper (10-22mm Canon, 14mm Rokinon/Samyang, 11-16mm Tokina, etc).

Very best,

Good advice. Yes, i did make a few mistakes early on e.g. using the lens at the widest aperture just because i could. I did not have a concept of a "sweet spot" then. As i mentioned above, focus with this lens has been a bit tricky for me as i am never sure what to focus on I use autofocus primarily because i don't trust my eyes as much (helps to magnify though). I might need new spectacles.

Nick3434 wrote in post #16634153
Looks normal. The 10-20 lens is good, but c'mon, there is a reason it is what it is.

I struggled with mine at first, really, you want to shoot f8-12 if you can and either focus on subject, or hyper focal or focus first 3rd or whatever. Once you get used to it, it is a good lens.

Thanks. Reassures me that i still might get to utilize this lens to it's fullest potential. By focusing at first 3rd do you mean focus at the near spectators in those cricket pictures?

DreDaze wrote in post #16634308
it looks a littlesoft to me...but i do wonder if you have a filter on it as well...especially with the double flare in the first cricket shots...also stopping it down to about f8 should be the sweet spot

you do want to make sure you know where you are focusing, i typically focus about 4 feet in front of me, and with the large DOF everything else is in focus as well...if you point it to the other side of the stadium you're not going to get the best shot sometimes, or if you are shooting at f4, and aim too close you won't have the DOF extend all the way to infinity

i do agree with others that you don't want to over-analyze at 100%

UV Filter for Cricket but not for the others.I did focus on the other side of the ground as well. How do you focus 4 feet in front of you? On a specific subject 4 feet away?

GoHokiesGo wrote in post #16634378
It does take some practice to get used to the UWA, as with any lens. Out of my lenses, I think I've printed more photos and dramatic scenes from my 10-20mm than any other of my lenses; its a great lens.

I noticed on a few of your shots you were shooting wide open, but also at like 1/4000s shutter and iso1600. You could probably stop it down some and drop your iso, while keep plenty decent shutter speeds. The nice thing about an UWA is that you dont need a very high shutter to keep things sharp. You were missing exif info on flickr for quite a few, but I'd recommend stopping down, dropping the iso and not using such a fast shutter.

Yes, sorry about the missing EXIF info. I took those beach shots the day after i got the lens so i made quite a few noob mistakes. The cricket shots were taken yesterday so i was more on the money with the shutter and ISO. Messed up the Aperture for a few of those shots though by not paying enough attention.

I think i might have a focusing problem. I just don't know where to focus in UWA

Can the thread title changed to something like 'How do i get best results with a Sigma 10-20?' Have to wonder how much user error is responsible for the bad rep brands get. If Canon were scrutinised so harshly by amateurs i'd think there's liklely to be a lot more problems found.

oxygen45 wrote in post #16634849
Can the thread title changed to something like 'How do i get best results with a Sigma 10-20?' Have to wonder how much user error is responsible for the bad rep brands get. If Canon were scrutinised so harshly by amateurs i'd think there's liklely to be a lot more problems found.

The same amateur is plenty satisfied with the Canon 24-70mm F2.8, Canon 100-400mm F4.5-5.6, Sigma 30mm F1.4, Canon 50mm F1.4 and even the stock lenses. I know what to expect from those lenses and i do get reasonable results.

With this lens, i am not sure whether i am expecting too much. My images look soft to me. Some members suggested i might have been focusing wrong and i am paying due consideration to that possibility. The field of view with this lens is very large and often i find myself struggle to decide what object to focus on. That does not automatically make it the reason for the problem. I am however, keen to rule out that possibility by seeking further focusing advice to see if that improves sharpness.

I don't care if the thread title changes as long as it helps me get sharp pictures with this lens

The compositions are boring and do nothing to move the eye toward anything in particular. Split horizon at the center just doesn't work. Just my opinion obviously. Sorry.

The beach shot with the stairs is the only one that works for me. And it does look a little soft.

UWA take a lot of practice. Get down low and try some new angles. You are correct about the FOV. Find something to focus on... then post more for critique.

FarmerTed1971 wrote in post #16635095
The compositions are boring and do nothing to move the eye toward anything in particular. Split horizon at the center just doesn't work. Just my opinion obviously. Sorry.

The beach shot with the stairs is the only one that works for me. And it does look a little soft.

UWA take a lot of practice. Get down low and try some new angles. You are correct about the FOV. Find something to focus on... then post more for critique.

No, i appreciate your advice. Those pictures (except the ones with the stairs)were basically just point and shoots to see what the sharpness and general results would be like.
There's definitely a lot for me to learn in terms of composition of images and i hope it comes to me in due time.

I guess the best thing to do is to go out with a tripod and shoot some more with proper focus. I'll definitely do my homework this time before posting some more images.

first off i'd ditch the UV filter, or at least take shots with it on, and then off to see if it is having a negative impact

as for focusing 4 feet out, for instance, i would've focused on one of the people in front of you instead of just pointing it to the other side of the stadium in the cricket shots...just do a focus recopmose...make sure you're not stopping the lens down too much, and getting negative results from diffraction as well....in my opinion there's no point to go smaller than f11

DreDaze wrote in post #16635549
first off i'd ditch the UV filter, or at least take shots with it on, and then off to see if it is having a negative impact

as for focusing 4 feet out, for instance, i would've focused on one of the people in front of you instead of just pointing it to the other side of the stadium in the cricket shots...just do a focus recopmose...make sure you're not stopping the lens down too much, and getting negative results from diffraction as well....in my opinion there's no point to go smaller than f11

Yes that's the first thing i'll do even though i was assured by the salesman/self proclaimed camera expert that the filter will not affect the IQ at all.

Thanks for your input so far. Much appreciated.

Xscaper wrote in post #16635665
Yes that's the first thing i'll do even though i was assured by the salesman/self proclaimed camera expert that the filter will not affect the IQ at all.

Thanks for your input so far. Much appreciated.

no offense to you, but i wouldn't trust the salesmen at the camera store you went to...especially after you complained about the lens, and the way they reviewed it was on the LCD...

Most of the photos do look soft at 100% to me. I used to own a Sigma 10-20mm and my shots are much sharper than the ones you posted. Having said that, I was using the lens on a 10MP Canon 40D, which won't reveal a lens' faults like the newer 18MP sensors do. Also, I generally shot the lens stopped down to f/8 to increase sharpness and depth of field. Finally, any lens will look a bit soft at ISO 1600, especially if you have noise reduction enabled.

MalVeauX wrote in post #16633694
I remember when I first got my ultrawide, I instantly thought it was soft when I viewed it at 100% on a monitor. Pooped a little bit at the thought of it being that soft and instantly started getting ready to return it.

Big learning curve going to ultrawide and understanding the sharpness for the perspective or potential format it will be viewed. Good point about the show/print in regards to resolution. Hard lesson to learn for some (myself included).

IMAGE LINK: http://www.flickr.com/​photos/mwise1023/12093​995785/
DPP_0299 by Mwise1023, on Flickr

Very best,

I don't think my images are drastically worse than yours. Maybe i WAS indeed expecting a bit too much from a UWA lens. It all looks good at full screen(30% magnification) but at 100% it's not very sharp at all. Maybe it's just the nature of the beast.

I took a few more pics recently. I'll update my first post with the new link.