What's the deal with lenses like this ????

[bbirnie]

Hi,

What is the deal with wide-angle lenses like this that attach to the end of your 18-55mm lens for example vs. a proper wide-angle lens. Thanks.

I understand there is a search function but sometimes it's nice to get new information and perhaps hear from someone who didn't respond to other posts about the same topic. So please if you are just going to tell me to use the search function then save it, and move on. Thanks.

 

[TiCoyote]

Is that one of those cheap add-on lenses on ebay? Poor image quality. Lots of distortion, flare, and CA. If you have a nice lens, don't add extra elements of a lower quality. A chain is only as strong as its weakest link, and glass is only as clear as its cloudiest element.

 

[bbirnie]

Ok, right........ I knew that part. But I was thinking that there would be ones made out of quality glass........ so other then the quality of the lens what are the disadvantages ?

Thanks !

 

[Derrel]

"Lots of distortion, flare, and CA."

 

[pbelarge]

Also the waste of good $$$.

 

[TiCoyote]

...and it might steal your chickens and impregnate your daughter. Or the other way round.

 

[o hey tyler]

I think the general consensus is that you shouldn't buy this.

 

[JG_Coleman]

Ok, right........ I knew that part. But I was thinking that there would be ones made out of quality glass........ so other then the quality of the lens what are the disadvantages ?

Thanks !

It would be awesome if these little attachments worked well. Too bad they don't.

From my understanding, there are many factors at work that make these pretty undesirable.

Of course, there are the problems that have already been mentioned -distortion, chromatic abberation, and flare- which are the glaring difficulties.

That they aren't made with quality glass is really only part of the problem, though. Even a model that IS made with relatively high-quality glass would likely still produce a major degradation of image quality.

The problem is that you are essentially adding another glass element to your lens which A) was not anticipated by your lens manufacturer and B) is not matched to the specs of that particular lens. Even relatively inexpensive lenses -like Nikon's 18-55mm kit lens, for example- are still manufactured with tight specs and involve 7 lens elements that all work in cooperation to produce a good image. When you drop a piece of glass in front of them that drastically changes the direction and qualities of the light entering the lens, you sort of change the whole game... and those built-in elements simply aren't going to perform as well.

Now, if Nikon released a "matched" screw-on wide-angle attachment that it specifically advertised as being geared towards an 18-55mm kit lens... it'd probably be much nicer than the ordinary attachment you'd find on eBay. The glass would be specifically shaped to provide the best match to the lenses elements. Judging by the fact that Nikon has never made such a product (as far as I know), however, it's really more trouble than its worth... and even when carefully matched to a lens would probably still produce all kinds of image quality issues.

That being said, it'll work... it just won't produce great images. Not bad if you're just trying to take some photos of the family on vacation... but nothing you'd want to get involved with if you're sincere about your photography in its own right.

 

[tirediron]

...A chain is only as strong as its weakest link, and glass is only as clear as its cloudiest element.

I like that. May I use it?

 

[Blake.Oney]

Okay, I may be wrong here, but with video camera these actually increase field of view. It seems to me, though that since SLR lenses already have their FOV that all this would really be doing is distorting, or giving a "fish eye" look to an 18mm FOV. If anyone knows if it will actually give a wider FOV then let me know, but I don't think it does.

 

[SrBiscuit]

i has one.
it is fun to **** with.
i dont get much IQ out of it.

here's a shot i took with it.

you can see that really only the very center is in focus.
you cant really rely on these things unless the above image is of a quality thats acceptable to you.

 

[TiCoyote]

...A chain is only as strong as its weakest link, and glass is only as clear as its cloudiest element.

I like that. May I use it?

Sure thing, buddy. Thanks for the compliment!