Expert: John Oliverio - 7/26/2009

Question
HI, I was thinking of getting a super zoom lens to get shots of things in the mountains. I have a four thirds standard Olympus and one thing I ran across is the Opteka 500mm-1000mm zoom lens and it only costs around $100. Where most prime 50mm go for $300 and zooms up to 300mm can reach $800, is this Opteka too good to be true?

Answer
Andrew,

Well, I've never heard of the Opteka brand.  But that is not surprising. Companies like that come and go every couple of years.  A common brand for lenses like that when I was a kid was Spiratone.  
I did a google search for Opteka and found nothing useful.  The few reviews I found were either user reviews (which are fairly useless), or AD copy disguised as a review.  
But I don't really need to read a review for a lens like this.  I've got a pretty good idea of what it is all about.

Is it too good to be true?  Well, that depends on what you expect from it.  And of course there is the old saw:  You Get What You Pay For. There are very good reason that good lenses are expensive.  They are simply good.  The lenses you ask about come in two variates.  Both are basically cheap telescope designs.  The long one (we used to call them "stove pipes") is kinda like a refracting telescope and the short one is basically a reflecting telescope (CAT lens).  

If you need a lot of power and don't need high quality images then these lenses would be great.  Hunters and bird watchers come to mind.  They really just want to document what they see, not frame their pictures for the wall.

Some of the issues to be aware of.
The lens will be manual focus.
The max aperture is f/8.  It is a dark lens and needs a lot of light.
The lens is excessively powerful (particularly on Olympus with a 2x field of view crop)so even with daylight you will need a tripod.  On your camera, it will actually be a 2000mm lens.  Nobody could hand hold that.
Your images will suffer from softness and chromatic aberration.  

So, there are uses for a lens like this.  But only if you aren't concerned about image quality.
Also, be aware that these are not "zoom" lenses.  They are either 500mm or 1000mm.  They give you a tube to put on the lens to increase the focal length.  Also, the aperture is usually (but not always) preset.  In other words, it is stuck at f/8 at 500mm and f16 at 1000mm.

Hope this helps.

John

PS:  I just found some pictures of the lenses.  They look EXACTLY like the spiratone and Quantary (Ritz camera house brand) lenses from 20 years ago.  Just in a cool new box.  And using new marketing terms like HiDef and Precision.  You'll notice that the normally priced lenses don't use terms like that.  Because they don't mean anything.