Why you should buy quality glass.

[HJF]

I was curious about the difference between a Canon L-Series lens and a cheapy Sigma so I shot a quick comparison shot. Both on a Canon 5D MK II, ISO 1600 and 50mm.

Sigma 28-300 F3.5-6.3 was shot at F4.5 since it can't do F4.
Canon 24-105 was shot at F4.

This is a 100% crop from the center straight from photoshop with no processing at all other than cropping.

At first I thought it was the IS on the Canon and I was shaking with the Sigma but turning off the IS yielded the same result. In the full image the vignetting is also pretty bad on the Sigma in all corners.

I'm actually wondering if the Sigma is just maybe a really bad copy?

Pretty clear the Sigma can't resolve even sort of enough resolution for the 5D.

 

[noxibox]

I'd be interested in how similar range zooms compare. Also while the Sigma looks soft at 100% is this difference clearly visible at normal print sizes?

 

[koffiejunkie]

The Sigma 28-300 is easily the worst lens I've owned. Even the decades old Vivitar 28-210 (which is known for it's badness) is better.

 

[koffiejunkie]

I did do some similar tests with the 28-300 and the Sigma 70-200 and Canon 18-200 IS before to figure out which ones to sell and which ones to keep. I'll post them later.

 

[koffiejunkie]

Right, so I had the Sigma 28-300mm f/3.5-5.6, which I bought for my film body, but it's been a bit of a disappointment. I also had a 70-300mm f/4-5.6 APO DG Macro, which is an OK lens. Not great but nothing much to complain about either in the optical deparment. Lastly, I had a Canon 18-200mm f/3.5-5.6 IS which I bought as the kit lens with my 50D.

Here are a bunch of crops I did at 200mm. Camera was on a weighed-down tripod, I used flash as far as I remember, focus distance was about 4-5m, I used a remote shutter, and mirror lockup to make sure things are as stable as it can be.

Sigma 28-300mm f/3.5-5.6 @ 200mm, f/5.6...............................and f/8

Sigma 70-300mm f/4-5.6 @ 200mm, f/5.6...............................and f/8

Canon EF-S 18-200 IS @ 200mm, f/5.6.....................................f/8

 

[koffiejunkie]

And at 300mm

Sigma 28-300mm f/3.5-5.6 @ 300mm, f/5.6...............................and f/8

Sigma 70-300mm f/4-5.6 @ 300mm, f/5.6...............................and f/8

It think the pictures speak for themselves. But I'm going to state the obvious anyway. The Sigma 70-300mm absolutely wipes the floor with the other two.

It's also worth noting 200mm means different things on different lenses. The 70-300 is significantly longer than the other two. That's why I continue to recommend it to people who want a 70-300 on a budget.

 

[bwana]

Lol. Lens snobs

 

[koffiejunkie]

Lol. Lens snobs

Says the man with the 300mm f/2.8 L....

 

[bwana]

Says the man with the 300mm f/2.8 L....

And a 28-300mm Sigma.

 

[koffiejunkie]

And a 28-300mm Sigma.

Which I'm sure is spending loads of time on your camera at the moment?

 

[bwana]

Which I'm sure is spending loads of time on your camera at the moment?

Sure it does. Or do you think I slap on 2.5kg of glass just to go for a stroll with the wife and kids?

 

[koffiejunkie]

No but I would chose the 24-70 for a walk-around if I owned both. Mybe yours is better - mine was rubbish.

Different strokes for different folks I guess.

 

[bwana]

No but I would chose the 24-70 for a walk-around if I owned both. Mybe yours is better - mine was rubbish.

Different strokes for different folks I guess.

IThe 28-300 is lighter and has three times the range. The 24-70 is also three times the price and would be more of a hassle to replace.

 

[Moklet Kcuf]

The sigma shot just looks out of focus

 

[koffiejunkie]

It does. Unfortunately, that's as good as it got. I spent ages bracketing focus and checking to get the best possible shot.

 

[Synaesthesia]

The 28-300 was never the sharpest lens around - it made some extreme compromises for the extreme zoom range. That said I'm actually blown away by the difference between those two shots. It shouldn't be *that* bad. Try making another comparison shot - but be sure to have your camera on a tripod or lying on a table to eliminate motion blur, and manually focus too to eliminate focal blur.

Camera shake and focal blur are still the #1 cause of unsharp images! I've never seen someone comment on a photo saying, great photo, pity your lens wasn't sharp enough!

 

[koffiejunkie]

The 28-300 was never the sharpest lens around - it made some extreme compromises for the extreme zoom range.

I'm guessing mine might have been a much older model than bwana's one. Nevertheless, the compromises was pretty obvious. Lens design have come a long way since then

That said I'm actually blown away by the difference between those two shots.

I was blown away by how good the Sigma 70-300 APO was.

It shouldn't be *that* bad. Try making another comparison shot

I can't. I sold the 18-200 when I bought the 24-105L, and sold the 28-300 after this test. And when I got my first taste of Canon 70-200mm f/2.8L, I sold the 70-300 too.

but be sure to have your camera on a tripod or lying on a table to eliminate motion blur, and manually focus too to eliminate focal blur.

Those shots were taken with a tripod (weighed down too), and flash so that I could get a fast enough shutter. I also focus bracketed as best I could and ended up using the best shots. To be fair, as mushy as the shots from the 70-300 look, if I downsize it to the size imags that we post on this forum, you wouldn't be able to tell. I'm sure if I printed postcard size prints it would look good too.

Camera shake and focal blur are still the #1 cause of unsharp images! I've never seen someone comment on a photo saying, great photo, pity your lens wasn't sharp enough!

I guess you haven't spent much time on the dpreview.com forums then?

 

[Synaesthesia]

I guess you haven't spent much time on the dpreview.com forums then?

ha ha, I meant *normal* people.

Well then that lens sucked.

I'm actually happy - your post made me appreciate the fact that I have decent lenses all over again!

 

[koffiejunkie]

Ha ha! Glad I could help.

 

[bwana]

Right, so I had the Sigma 28-300mm f/3.5-5.6, which I bought for my film body, but it's been a bit of a disappointment. I also had a 70-300mm f/4-5.6 APO DG Macro, which is an OK lens. Not great but nothing much to complain about either in the optical deparment. Lastly, I had a Canon 18-200mm f/3.5-5.6 IS which I bought as the kit lens with my 50D.

I was blown away by how good the Sigma 70-300 APO was.

Which one was it?