$79 Lens-Is there distortion I'm missing?

[stsinner]

I got my Sigma 70-300 DG Macro new online for $79, and I'm in love with it. But as I'm reading, I keep running into people saying that cheap lenses have things like Chromatic Aberration, Barrel Distortion and other poor qualities. Being new to photography, I've never used any expensive lenses, so I don't have a reference point for quality.

In most of these shots, I'm zoomed all the way in to 300mm. Is there distortion that I'm not seeing? I was told one of my previous pictures had some distortion, but I couldn't see it. I'm hoping I got lucky and got a good lens.

These are just test shots for illustration purposes. Thanks for the info.

 

[AlexColeman]

No, they are just notorious for bad QC, and usually have issues, looks like you got a good copy though, the photos show that.

 

[Big Mike]

It's often hard to explain or quantify the differences in image quality from one lens to another. But I will say that when you do use a top quality lens and you nail the shot....you will see the difference.

Now, is that difference worth the extra cost (2, 3, 4 or 5 times as much)? That's up to you.

 

[AlexColeman]

Not necessarily for him, these "happy snaps" show that he won't need 10k L glass, nor does anyone except those who know they need it, as of now, I am more than happy with my D90 and 16-85.

 

[stsinner]

Mike, one thing I do notice is that the barrel of this lens is not easy to turn or fluid at all. I'll bet that's one big difference in the cheap and expensive lenses.

Here is a picture I took in Boston with my 70-300, and I don't think it's bad. What I'm curious about is whether you can tell that this is a cheap lens, or does it pass muster pretty well?

And this one was at 300mm:

 

[benhasajeep]

To check for distorion, take a picture of a brick wall. Make sure you have it parallel, and level. Use a couple zoom settings of same picture (on tripod).

If there is distortion it will show up in the lines in the bricks. Will have a curve to them instead of being flat.

For other tests you can look on line for lens test chart. Print one out and set it up per the instructions.

But if your happy with it. Why check for problems. Just shoot with it and be happy.

 

[Big Mike]

I think they could have more 'pop'.

Top quality lenses usually give sharper images (hard to tell at this size) but they often have more contrast and better color rendition. Some of this you can replicate with software but there is still a quality that you can see with top quality lenses.
Do a search for images taken with Leica lenses...

This shot was taken with my Canon 75-300mm 'consumer grade' lens. I've taken better shots with it, but this is probably typical.

This was taken with a borrowed 100-400mm L lens.

 

[AlexColeman]

The difference is incredible with the stuff I have shot, but for the average consumer, around the house snaps won't require professional "pop".

 

[chris miss]

I bought this lens in June (just got my xti in May, so I'm a total novice) and I've been pretty happy with it. It was recommended to me because it was reasonably priced and at my level of experience (none), it would give me a good idea of what that focal range was capable of. I've notice and have heard that at 300mm, your pictures will be soft. That disappointed me a little because I really wanted to take close-ups of birds and I can't get close enough with a shorter focal length. It was nice that it had the macro feature as well, so I could get a taste of macro photography. This is one of my favorite macro shots. I'm just learning and this is a good lens for that purpose. I'll probably want to move up to something better as I gain experience. But for the money, you can't beat it. Sounds like you got a great deal at that price!

 

[AlexColeman]

Yeah, it is fine for starting, but soon you will be bumping up against a "glass" ceiling, as your skills improve.

 

[stsinner]

Chris, what lens is it? The kit lens? If you posted it, I read right over it.

 

[AlexColeman]

I believe he is referring to your lens.

 

[Overread]

I have that very same lens - its a great starting out lens - a long focal range and good macro (well for flowerheads at least) feature, however it is very much a lens that needs a good solid tripod under it for good results that the longer end. I was never really able to get good handheld results from it at the time I was using it (though I fully admit to only having 6ish months of self taught experience in photography and it was not the only thing I did -- though I tried my best ot make it like that )

some of the best results that I got from that lens were tripod mounted macros of flowers, that sort of subject proved to be its best as it was not forcing the lens to focus on further off subjects, but rather on closer ones. I did notice that its range for a decent shot at the 300mm end was around 5-6meters and beyond that softness really started to kick in (At leat for wildlife).
And whilst it reamains the only lens I have that reaches 300mm I have not touched it since getting my 70-200mm L - the quality difference was noticable and justifiable (At least to me) for the price I paid for the upgrade - however the sigma Forced me to learn to use it properly to get decent results, whilst the higher quality lens can cover up some of my shortfallings at times.
Keep at it with the lens

 

[chris miss]

Chris, what lens is it? The kit lens? If you posted it, I read right over it.

Yes, it was the same lens you were posting about (Sigma 70-300 f/4-5.6 APO DG Macro). Sorry I wasn't clear about that.

 

[Overread]

If I read right Stsinner has the non-apo edition - the older version of the sigma (which is the one I have) at macro I think the quality might be on par between the two, but from what I have seen the APO is the sharper of the two lenses, enough to warrent investing in it over the non-apo edition BUT not enough to warrent upgrading to it. That money is better saved for an all round better lens.
if you want examples check here:
http://overread.wordpress.com/2008/03/
a few months before and after this was about the only lens I ever used ( I had it and the kit lens and nothing else - I mark at the start of a section what lens is used for photos so you can keep up with which on I used.)