Camera lens problem...

[manarak]

I played around with my 30mm Sigma f/1.4 lens, and I wasn't too impressed with landscape shots.

I played around with all settings, but I couldn't get really crisp shots.

Then I made comparative shots with the 18-135 standard zoom (!) from Canon, and the Zoom was sharper at 30mm than the Sigma prime lens.

Unfortunately, the RMA process takes forever at Sigma, so I will bring this lens with me to the LOS in august and RMA it later.

The lens works fine for Portrait though, so I'll put it to use!

[rxpharm]

Manarak, what apertures did you try it at for landscapes? Usually fixed focus lens are sharpest around f 8.0 - f 11.00. If you were trying the wider apertures it would definitely be less sharp. However it shouldn't be worse than the standard zoom at the same settings.

[azza33]

Stick with the canon lens - overpriced maybe but in reality a couple of lens won't be the end of you- specially with the money you made on those aussie mining juniors

[manarak]

(rxpharm @ Jul. 01 2010,06:48) Manarak, what apertures did you try it at for landscapes? Usually fixed focus lens are sharpest around f 8.0 - f 11.00. If you were trying the wider apertures it would definitely be less sharp. However it shouldn't be worse than the standard zoom at the same settings.

f11 in full sunshine at ISO 100.

I really do think the lens is bad, because a lot of people praised it for its sharpness.

And the Canon lens was not overpriced, it was even pretty cheap, I got it as a kit lens with the 550D.

But the f/3.5-5.6 Canon lens can't cut it in low light - the Sigma is f/1.4 and I can get some good shots with bar lighting (low light).

Canon in the day, Sigma in the night.

[rxpharm]

Ok, definitely do an RMA, but also send a CD/DVD burned with a few photos illustrating the problem and comparing with the kit zoom. That should facilitate the approval process.

As for Canon lens being the only ones to use - I disagree, both Tamron and Sigma make some lenses that have very good image quality at good prices compared to the mainstream camera makers.

[Chinaman]

(manarak @ Jul. 01 2010,07:15) Canon in the day, Sigma in the night.

Soi 6 and WS ;-)

[Chinaman]

(rxpharm @ Jul. 01 2010,08:41) As for Canon lens being the only ones to use - I disagree, both Tamron and Sigma make some lenses that have very good image quality at good prices compared to the mainstream camera makers.

I might be completely wrong but I have this feeling that out of 100 Canon lenses (same lens) versus 100 Sigmas, etc., one is more likely to get a dud within the S or T lenses, but as I said, just a feeling ...

[manarak]

(Chinaman @ Jul. 02 2010,14:34)

(manarak @ Jul. 01 2010,07:15) Canon in the day, Sigma in the night.

Soi 6 and WS ;-)

you forget soi 10, soi 7/8, pook swan, and... my loom!

[Chinaman]

(manarak @ Jul. 02 2010,15:32)

(Chinaman @ Jul. 02 2010,14:34)

(manarak @ Jul. 01 2010,07:15) Canon in the day, Sigma in the night.

Soi 6 and WS ;-)

you forget soi 10, soi 7/8, pook swan, and... my loom!

well, u only mentioned 2 lens-makers

don't overdo it, u r getting older ;-)

[manarak]

Some more experiments with the Sigma lens showed that the lens has often trouble with autofocus at any distance.

I got reasonably sharp shots with AF override.

But to do this, I need to switch on live view and magnify 2x, because the details are too small to see in the viewfinder.

[azza33]

That's the problem with any non canon lens... no guarantee the AF system will work and the algorithm are correct.

Stick with Canon mate. Just choose a couple of lens that you'll use the most.

And ensure the are not the EF-S ones, else compatibility will likely be an issue should you change the camera body some time in the future.

[rxpharm]

I disagree - Tamron pays a license fee to the various camera manufacturers to use their information to correctly chip their lenses. However, I do understand that Sigma attempts to reverse engineer things to avoid the licensing fees.

However, when there is a problem with the Sigma lens - they will replace it and hopefully your replacement will work properly.

Testing by various sites show that there is little difference in image quality between the top lenses of generic companies like Tamron and Sigma vs the regular lenses from Nikon, Canon, Pentax, Olympus, Sony, Minolta. The differences start to show when you compare the top lenses like the Carl Ziess Sony or Canon L lenses which cost significantly more.

[manarak]

make the magnification 10x.

I've now gotten crisp-sharp shots using live view, 10x display magnification and manual focus.

Kinda defeats the "autofocus fast lens" concept, but it can be done.
I'll return the lens after my holiday :-)

at 1.4 no way to focus the head of the cock and the balls at the same time

[manarak]

it's definitely an autofocus problem, a random one.

I now tried to make some comparative shots, and the autofocus worked well, the difference to my manually adjusted shots is minimal.
:-(

just shot this one among others out my kitchen window.

on the crop, sharpness is fine.

[azza33]

(rxpharm @ Jul. 04 2010,20:27)

I disagree - Tamron pays a license fee to the various camera manufacturers to use their information to correctly chip their lenses. However, I do understand that Sigma attempts to reverse engineer things to avoid the licensing fees.

However, when there is a problem with the Sigma lens - they will replace it and hopefully your replacement will work properly.

Testing by various sites show that there is little difference in image quality between the top lenses of generic companies like Tamron and Sigma vs the regular lenses from Nikon, Canon, Pentax, Olympus, Sony, Minolta. The differences start to show when you compare the top lenses like the Carl Ziess Sony or Canon L lenses which cost significantly more.

Why would you buy any other lens than an L series?  

And as you have pointed out... they try and reverse engineer the algorithms.... so why bother with a hit an miss approach.

Buy an affordable L series for your