Are APO lenses any good??

Messages
98
Edit My Images
Yes
Being a total n00b i would like some info off the people that have the experience in lenses such as the APO ones.

I've been offered an 70 - 300mm APO Lens for a round number of £100

Thankyou in advance :)
 
TBPhotoGraphi><™;2957949 said:
Being a total n00b i would like some info off the people that have the experience in lenses such as the APO ones.

I've been offered an 70 - 300mm APO Lens for a round number of £100

Thankyou in advance :)
assuming its a sigma, they focus slower than a tortoise running a marathon
 
I'm just after something i can get some decent zoomage on other than my 18 - 55mm.

Having never looked through anything more than mine i'm not sure what will be more than adequate.
 
APO stands for apochromatic.

Quite simply different wavelengths of light focus at slightly different points in a non APO lens. All that APO means is that it is colour corrected in that all three primary colours are brought to the same point of focus.

Does not signify anything about performance or reliability so it's not the only designator of any kind of quality.

hope that helps
 
That is what apochromatic is supposed to mean.

But this is marketing speak, ie lies. What it actually means in this context is 'we'd like you to think this lens is better than it actually is'.

I am not aware of any camera lens that is truly apochromatic, at any price, outside of specialist laborarory optics.

It's in the same category is half-truths as 'macro zoom'.
 
it comes from the phrase "achromatic doublet" It is where 2 lenses with different and opposing amounts of spherical and chromatic aberration are cemented together. One lenses weaknesses cancel out the weakness of the other, and visa versa. In camera optics it is normally 3 lenses used togetherAPO indicates photographic usage

They dont need to be cemented together - its just the applications where they are used usually require it. They tend to be thicker and comparitivley quite heavy

Shall I do Aspheric next?
 
Last edited:
it comes from the phrase "achromatic doublet" It is where 2 lenses with different and opposing amounts of spherical and chromatic aberration are cemented together. One lenses weaknesses cancel out the weakness of the other, and visa versa. In camera optics it is normally 3 lenses used togetherAPO indicates photographic usage

They dont need to be cemented together - its just the applications where they are used usually require it. They tend to be thicker and comparitivley quite heavy

Shall I do Aspheric next?

Aspheric is a savory jelly made from meat stock and sometimes supplemented with gelatin to ensure that it sets. The food has a long culinary history, ...

although i could be wrong
 
Aspheric is a savory jelly made from meat stock and sometimes supplemented with gelatin to ensure that it sets. The food has a long culinary history, ...

although i could be wrong
Thats Aspic
 
it comes from the phrase "achromatic doublet"

[PEDANT]
apo comes from shortening apochromatic, not from the phrase "achromatic doublet". Also, an "achromatic doublet" only brings together two of the three primaries together at the same focal point, so isn't truly apochromatic.....
[/PEDANT]
 
correct. however, it is normally at the 2 ends of the visual spectrum where most of the issue is, hence the reason for doublets. We have all seen the fringing lenses give, that's what achromatic lenses correct. In theory, we could use a stack of lenses and correct all sorts of colours. The correction of the "third colour" is more about marketing. Red and Blue are loosely at the two ends of the spectrum, most lenses focus the middle of the spectrum (green) properly anyway

APOchromatics also include the correction of spherical aberrations (but in practice if the lens designers were bothered enough to use a achromatic lens, they figured out the spherical aberrations anyway)
 
An alternative to consider, and it's a little more expensive, but the EFS 55-250 is a great little performer (it's not an APO, and you do get some CA, but the correction is actually very good for the price ;)). The IS (Image Stabiliser) is a real boon too. Not the fastest to focus, but as long as you're not trying anything too awkward, like relying on the AF for something like flying insects (I did try :D)... it'll do a good job of it.

It is possible to get a doublet with exotic glass, that is so well corrected for all colours, it performs as well or in some cases better then some far more expensive triplet lenses (I've not experienced that, but I've seen it indicated by others). My ED telescope is a doublet and, even with 20 minute exposures, I've never seen a hint of CA creeping in, and this has also been confirmed with many other Astro imagers with the same optics and far more experience than I.
 
Getting away from the technical debate!

The Sigma 70-300mm APO was the budget telephoto of choice for many years and is a perfectly adequate budget lens, in recent times it's mantle as the budget telephoto of choice has been taken on by the Canon 55-250is which allthough shorter is smaller, lighter, sharper and has very good IS which is a real bonus for hand held use.

The Sigma 70-300mm APO is still a pretty decent lens, the focusing is nothing like as bad as some here will tell you and for £100 you won't be disapointed and won't loose much money should you decide to sell it in the future.
 
Another vote for the Sigma 70-300 APO. It also has a "Macro" setting which, while not true 1:1 macro, does enable you to focus to 1:2. Handy for larger bugs although you have to stop down to f8 or smaller to get sharp pics at 300mm, and use a tripod or other support.


Banded Demoiselle by jomike, on Flickr

My Nikon screw drive focus version is noisy when focusing, but not particularly slow in good light.
 
I have one, for the money its good, buy a used one and like others say it won't loose much so can always trade up. I've shot football, Rugby and Safari with mine and they pics came out ok.
 
For a £100 pound it'll be well worth the money, a cheap way to decide if you like/want to use a telephoto - you will -! and a chance to save for a better one, selling this one for almost what you paid.
I've seen a lot of good photos taken with one.

<snip>

Shall I do Aspheric next?


I thought he was a cartoon Gaul.....:exit:
 
Back
Top