Difference between non APO and APO lenses

I'm planning to buy a Sigma 70-300 lens for my EOS 300D. There is a

new model with APO correction but the older 'non APO' lens is cheaper

(about half price - and that's quite important for me). Could you

please tell me if it is worth to buy the APO version or the non APO

will be sufficient? Is there a noticeable difference on the pictures

(i.e. sharpness in tele-position...)?

Thanks in advance.

A few years back Practical Photography compared the two lenses (and several other lenses in this range). Their results showed that while the APO lens was slightly better on the long side (near 300mm) the non-APO was actually a tad better on the short end. Go figure. They ended up recommending the non-APO I assume based on the marginal difference in optical quality and substantial cost difference.

Popular Photo also did a comparison of these two Sigma lenses a couple years ago. As I recall, their samples showed them about equal at the wide end and continuing to 200mm. At 300mm the APO version was a bit better. But as Douglas mentioned, the difference wasn't all that substantial if you just looked at the sample image crops. However, I believe, PopPhoto did recommend buying the APO version if you: a) had the money to spend, b) wanted the best one of these two lenses.

 

Some users claim that their Sigma 70-300 APO is the best thing being sold today, and others complain that it wasn't worth the extra money, and now they want to unload it. The usual consumer reviews place the APO's image quality at or near the top of the 300mm telezooms being offered today, but only by a very small margin.

 

BTW, I have been told that there was an older Sigam APO version before this one. I have heard that the newer one is better than the older one. I don't know.

 

APO is short for apochromatic, I believe. It's a name that a lot of lenses get because they use an expensive glass type for at least one of the lens elements, in the hopes that it will reduce chromatic abertions (CA). Sigma always uses the term for any of there lenses like this, but others, like Canon, never use the term, but often have multiple high index glass elements anyway. Also, it's not the only way to make a good lens with low CA, so some non-APO lenses are better than the APO versions.

I have only ever owned one lens in APO and non-APO version - a Tokina 400mm f5.6 in Minolta manual focus mount. I never did any systematic testing, but in everyday use, the difference in results was indistinguishable for me. Since the APO lens (SD in Tokina speak) was about twice the price of the non-APO (RMC) lens, I sold the SD and kept the RMC.</p>

 

<img src="http://d6d2h4gfvy8t8.cloudfront.net/3105033-md.jpg" alt="name"></p>

 

<i>Minolta XD-7, Tokina RMC 400mm f/5.6</i>

BTW, what camera are you mounting this on? There are some brand name lenses in this zoom range that are probably as good or better than the Sigmas, and some of them don't cost any more. In fact, at a lot of places, the Canon 75-300 is less than the Sigma DL version. If the price is similar, I would go with the camera brand lens if only for it's improved trade in value.

If you are shopping locally, you should be allowed a few frames through the shop door, pixelpeeping at home and picking up the lens the next day.

 

I got my Sigma APO used via ebay and am rather disappointed with the results, especially in macro mode, but I own no telezoom worth praising yet.

The 70-300 DL uses regular glass for all its front elements, whereas the APO version uses special glass for both positive front elements, probably keeping chromatic aberrations better under control. Some people claim that the difference is visible and is worth the extra $80.

 

APO is meant to stand for apochromatic, which is theoreticall an optical design with second-order correction of chromatic aberrations.

 

I would expect either variant to show a drop of quality at the longest focal lengths, at large apertures and at short focusing distances, but that's common to all such lenses in that price range.

Main difference:

 

Manufacterer's hype and engineering speak, 85 % of it, and maybe a slight even negligible difference ... on 2% of your shots, but I am not certain which one will be better on those 2% of shots ...

 

Of course there are much better lenses in that range around. But that is not what you asked about.

Both George Lepp and Modern Photography compared several Sigma lenses in both APO and non-APO flavors, but not the 70-300. In each case there was a noticeable image improvement with the APO versions, especially at the longer focal lengths. I have used both the 400 f/5.6 and 70-210 f/3.5-f/4.5 Sigma APOs, and found them to be very good. If I had to choose, I would spring for the APO if price was not excessive. Optionally, I would think about acquiring a used lens from someone like KEH, Adorama, or B&H.

The first thing i should point out is that the 70-300 DL macro super(non apo) and 70-300 Apo macro super II are both current models.If you are buying an older version you should be aware that it may not work on the latest canon cameras due to software problems(if you have canon).

<P>I must say that i've found sigma quality control to be absolutally horrific.

<P>I recommend you definitely avoid the non apo madel for a start.Besides the QC issues it's not a very good lens anyway according to quite a few users.

<P>The Apo version on the other hand has a good reputation but also has QC problems... as i've personally found.

<BR>There are other brand lenses that are well worth looking at.See this thread for a detailed i've just written-

<P>http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00CQhw

 

<P>The bottom line is- buy the sigma Apo but be sure to buy it where they will happily exchange it if you get a dud.

<BR>......or go for another brand.