18-200: this'll do

[jimr-pdx]

Last fall I went for the Tamron 18-250 and it hasn't disappointed. Last week, however, a Ritz-closeout deal could not be refused: a Quantaray/Sigma 18-200 for an excellent price. After several tests (both side by side and separately), I find that the lighter weight, slightly faster focus and equivalent image quality has me leaning to the newer lens. I never thought I'd say the 18-250 was expendable.. but there it is.
The primary good news from this is that I can swap out the 18-250 and finance my 'final' lens - one of the 17-xx models most likely, or perhaps a 16-105. The 17-70 has some advantages, since it would focus close & match up with my Minolta 70-210 - plus it zooms 'backwards' like the 18-200!

A nice iris shot from the weekend with the 18-200, no PP:

Original (for zooming in) + others at http://picasaweb.google.com/alphaPDX/qsigma

[dr4gon]

Looks pretty good. How much was it? I saw a bunch of old minolta quantaray lenses in the kit range 20x-80mm or so for really cheap, some like <$20.

[sparkie1263]

I had a old Quantaray 70-300 Lens and the AF stripped the plastic. I had to remove the AF drive on the lens so I could use it as a MF lens. I was told the AF motor was too powerful for those lens. I would wait and see before you get rid of the other lens. Maybe Don can explain this better. How much do you want for the 18-250?? LOL
Frank

[DonSchap]

It is a rare thing to have people comment positively on SIGMA lenses, so I'll just hold my tongue. Mmmmprh bbbmmmf. Okay okay ... that's a bit too hard.

Anyway ... the biggest thing I have always argued is that the TAMRON 18-200 is nowhere close to the TAMRON 18-250 in performance and over image quality. They simply are different and the 18-250 is a superior lens in comparison. I did not bring the SIGMA version into the argument, although I probably would have never done a comparison, anyway. I appreciate you doing one, Jim. It would also be very cool if you could do a text or "pattern" image side-by-side ... so we all could appreciate it. Also, use a tripod when you do this, just to eliminate any issues about camera-shake.

[jimr-pdx]

The Q-ray was $144, and that Sigma 28-90 Macro was $10 and change. Deals, steals, either way it makes up for my failures at several C-City stores. I'll grab a tripod and shoot a thing or two in the near future. All prior tests are hand-held. I took the series below with both lenses, this is a) the Sigma series and b) too small to prove anything. The Tamron shots were in essence identically sharp, but the trees in back were weirder for bokeh.



My very first new lens was a Sigma 18-125, and the kit lens was sharper! Back it went, and I've steered away from Sigs since then. I'd read that their 18-200 outgunned that lens, but I jumped straight to the Tamron 18-250 with no regrets. Now? I'd like to let the Mega Tamron go for a 17-70 (or 17-50) to get my faint-light failings fixed. I've a Minolta 50/1.7 for real low light, but the 17-70 would also give me close focus so I could sell that 28-90 for a killing.. maybe $11?

[jimr-pdx]

Don, I really tried to do what you asked.. but always five things to remember, and I do two of them. I set the camera on a tripod and shot a bunch of test shots, but SSS was on and iso set to Auto. I did use 2-second delay to minimize other quivering.**

Personally, I learned three things:

1. the Tamron is indeed uniformly better than the 18-200 at most settings
2. the 18-200 is indeed wider (at both 18 and 200)
3. test shots of boring stuff is.. boring!

I also learned that both lenses fail in the midsection while doing well at telephoto; check the 100mm side-by-side at the site below (sorry they're so small - guess that's Six things to remember). Details at 18mm were worse on the Sigma too. I posted my 'report' on the Picasa site as well.
I guess I'll be keeping the slower, heavier beast. Too bad, it would have financed a 17-70 all by itself I can't ask that much for the Quanta-sigma. I also like the faster focus, better bokeh, longer reach at f/5.6, closer focus, ... everything but IQ


http://picasaweb.google.com/alphaPDX/18xxtest#


** And by the way: is it just theory that SSS on a tripod is bad, or has someone 'proven' that it shakes to combat nonexistent shake? I seldom remember to turn it off, and I see no problems that are worth noting. Yet I hear it everywhere, with no counter-arguments. I guess KM/Sony says it's true in the manual, but it sure isn't easy to see..

[Peekayoh]

** And by the way: is it just theory that SSS on a tripod is bad, or has someone 'proven' that it shakes to combat nonexistent shake? I seldom remember to turn it off, and I see no problems that are worth noting. Yet I hear it everywhere, with no counter-arguments. I guess KM/Sony says it's true in the manual, but it sure isn't easy to see..

People have done tests which confirm that AS is best turned off when using a tripod.
Long lenses (300mm and over) may benefit from AS ON on a windy day at shutter speeds of 1/60th and shorter.
Don't use AS with Mirror Lock Up.

[jimr-pdx]

Don't use AS with Mirror Lock Up.

Ah, that dream again - mirror lock on my A200 I wasn't alone in holding my breath for a firmware update, hence the purple face!