Diff. btwn. Sigma 70-300 APO DG & Pentax FA J 75-300?

[mw_rip]

Hi. I would really appreciate if someone could tell me the difference between

the widely recommended Sigma APO DG 70-300/4-5.6 which is difficult to find in

stock anywhere, and the Pentax FA J 75-300/4.5-5.8 which seems to be available

everywhere but is never suggested when people ask for a good inexpensive zoom

recommendation. Why is this lens less popular/not as desirable? I tried

looking up all the lens codes for each company and while I found the correct

pages to decipher them, am still not sure I understand the difference. Thanks!

[nee_sung]

Well, I don't have the Sigma but I do have the Pentax. The "J" in the name of the Pentax lens has been taken to mean either "junk" or "junior". (I think Pentax meant it to be "junior"). But that pretty much tells you why.

 

The lens that I have serves my purpose extremely well (theatre shots from afar) but I really don't know if other people will be pleased with it. It's not really very sharp.

[renatoa]

The real meanning of J is "without aperture ring" and these are usualy FA lenses.

 

Lenses are fixed at the A position. Only fully functional on bodies which can set aperture manually on the body (All DSLR's, *ist, MZ-60 and 70, all PZ's)

[mw_rip]

Thanks everyone. Guess I'll go with the Sigma when I can find one.

[andrewg_ny]

I suspect that much of the reason that Sigma first and probably Tamron second are recommended over the various Pentax offerings in this 70/80-300/320 class is that you can still buy the Sigma and Tamron new and they are decent. Pentax's competitive offerings don't offer much the newer lenses don't, and the newer lenses generally offer closer focusing. FA-J can still be found, but it is a budget lens and as you've noticed, it doesn't get recommended much though I suspect the difference isn't all that significant. Most of the lenses in this class aren't particularly sharp at the long end of their zoom but perform OK when stopped down.

 

I picked up a used FA 80-320 last year; it is OK but nothing special. I generally use the DA 50-200 instead, partially because of size & weight. Pentax has a 70-300 on their roadmap, it will probably appear in about a year; I would expect this to be more competitive and possibly better.

 

-Andrew

[michael_kuhne]

The Sigma 70-300mm APO DG can be used on all Pentax model cameras, both old and new. It is of very good optical quality, especially from 70-2oomm, and good at 300mm. It has an unusually good close-up capability. The Pentax "J" lens, as Renato mentions, has restrictions as to the camera models it can be used on. The new Pentax lenses are made for digital camera use, and most are not compatible with film camera models.

[johnclinch]

You may find this review helpful

 

http://www.ephotozine.com/equipment/tests/testdetail.cfm?test_id=369

 

or this

 

http://www.photozone.de/8Reviews/lenses/sigma_70300_456/index.htm

 

They are both for the Sigma and it is more OK than great at 300 mm

[mw_rip]

Very informative-thanks to all for the info!