I want a new pentax lens.. but...

[Keebler]

Hi folks,

I'd like to upgrade my Pentax 50-200 to a 300 type lens. I'd like something in the 400 or better range, but with stabilization, they're way out of my range!

So, i've been looking at a Sigma 70-300 lens: http://www.sigmaphoto.com/lenses/lenses_all_details.asp?id=3303&navigator=3

It goes for $320 CDN

then I saw this guy:

PENTAX SMC FA J 75-300mm f4.5-5.8 AL - it retails for $249.99 CDN

The latter is from the 'film era' so a bit older. I did try both lenses and the Sigma appeared to be a tad overexposed, but I will admit that I shot something outside and about 20 mins later so maybe the light affected the shot.

Any thoughts as to which one is better? I can't seem to find a comparative website b/n these 2 particular lenses.

Any help would be great.

Cheers,
Keebler

 

[Keebler]

btw, i just realize something fairly important - the Sigma lens DID NOT have a UV filter on it, whereas my lens did. that would explain the overexposure a bit now wouldn't it? what a dolt.

i'm still deciding b/n the lenses though.

 

[Abstract]

I looked at http://www.pixel-peeper.com/, and they didn't have your lens on their list.

However, look at http://www.photozone.de/8Reviews/index.html. slrgear.com has your lens as well, but only 2 user reviews.

 

[Steamie]

Hi , I had the same decision to make recently try this link.

http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=24492831

It turns out the lens was a budget one and has a plastic mount and is apparently not that great optically.

 

[greg555]

A filter shouldn't affect the exposure (excluding using the wrong type of polarizer) since the metering is done through the lens and thus includes the filter effect.

An exposure problem probably means that the aperture closing mechanism isn't accurate enough. Say the camera decides the photo needs f8 and so it moves the aperture lever the specified distance to get f8. But if the lens is not precise enough the actual aperture may be f6.7 (1/2 stop overexposed) or f9.5 (1/2 stop underexposed).

But if the exposure problem happens when the lens aperture is wide open then there is a different problem.

Greg

btw, i just realize something fairly important - the Sigma lens DID NOT have a UV filter on it, whereas my lens did. that would explain the overexposure a bit now wouldn't it? what a dolt.

i'm still deciding b/n the lenses though.

 

[jpfisher]

The Sigma 50-500mm "Bigma" lens gets excellent marks from the Pentax shooters on dpreview who do nature photography and other applications that require a telephoto zoom. On the other hand, it's quite pricey.

At the moment, Pentax doesn't have any pro/prosumer grade telephoto zooms in production or readily available on the market.

Have you considered getting a longer prime lens for telephoto work and possibly a teleconverter? Willing to focus manually? I don't do a lot of telephoto type shooting, but I do have an old manual 300mm f/4 lens and a Tamron 1.4x teleconverter in my bag for when I do.

 

[filmamigo]

PENTAX SMC FA J 75-300mm f4.5-5.8 AL - it retails for $249.99 CDN

The latter is from the 'film era' so a bit older.

It's actually a current lens. The FA J series are contemporary to the *ist D, and work well on digital bodies. They are not renowned for their build quality, but I really like my FA J 18-35. The FA J lenses from Pentax are like the G lenses from Nikon -- no aperture ring, so you need a newer camera with electronic aperture control, and lighter build to keep the price down for consumers.

You've done the right thing by testing out the lenses on your camera. I'd go with what works/looks best. If you are happy with the FA J, go for it. Why wrestle with a lens that doesn't give you the performance you want out of the box? (i.e. having to make exposure compensations.)