Lens advice -- I need a fast autofocus zoom, I think?

dgaies · 12-20-2011, 01:21 PM

Originally posted by Mister Horrible

@Azzy, I don't think I'm parting w/ my 100 anytime soon. Do wish it had a focus limited on it, but love the bokeh and colors.

I'm kind of agreeing that the Tammy 70-200 might be an option-- it would give me some versatility and supplement my other lenses in other areas as well. Am concerned that some reviews say it is slow focusing.

Anyone have experience with the slower aperture lenses such as 50-200/55-300? I'm assumming their slow focusing as well.

The Tamron 70-200/2.8 isn't too bad in terms of focusing speed. It's on par with the DA*60-250/4. Something like the Sigma 70-200/2.8 HSM is going to be a bit faster, but I'd say the Tamron 70-200/2.8 (and DA*60-250) have reasonable AF speed.

Lenses like the 50-200 and 55-300 focuses fairly quickly in decent light, but tend to struggle a little more in low light because their max aperture is smaller. If you're considering one of them, I would recommend the 55-300 over the 50-200. It's optically better, and the extra reach is nice to have. The 55-300 is actually a very good value as compact consumer telephoto zooms go, so if you don't feel you need something faster, it's certainly an option worth considering.

Mister Horrible · 12-20-2011, 01:52 PM

I'm thinking I need to start saving up for a Tammy 70-200. Thanks guys.

chickenandavocado · 12-20-2011, 09:43 PM

Originally posted by DaveHolmes

Tammy 90mm macro... Only ever used a friends on Canon but was very fast focusing!

considering he already has the 100 macro i dont think its a good option

the focus of the tamron is slow especially in low light, my recommendation is tamron 70-200

sterretje · 12-20-2011, 10:01 PM

From experience, the DA55-300 can hunt as well; but I haven't tried it on a K5 (yet). No experience with 70-200, but you can research the Sigma 70-200/2.8 as well.

demp10 · 12-20-2011, 10:05 PM

Originally posted by Mister Horrible

Interesting ideas so far.

I think the Pentax 35-70 might be a little two wide for what I am doing. The nice thing about the 100 is that I can "crop closer" and still have something decent enough for a 4x6 print.

If your goal is to make 4x6 prints you can use practically any focal length down to 50mm, crop and still have enough pixels for an excellent print. All things being equal you need approximately about 8 MP for a 4x6. Anything beyond that and you need a magnifier to look at the pixels to see any differences.

If you are budget sensitive, the F 35-50 is an absolute steal. The focus is practically instant with a very short travel. It is very decent wide open and stellar at F8. Besides it is very lightweight and very small so you'll not intimidate the kids.

RioRico · 12-20-2011, 11:33 PM

I'll echo the suggestion of the small sharp agile F35-70, probably available by itself for around US$50. Use that whilst you're saving up for the Tammy 70-200.

Ah, since you already have a K5, you could go pervy and get a Bigma 50-500. Just let ISO float as you shoot the near and the far. There is nothing like it.

Mister Horrible · 12-21-2011, 06:06 AM

Thanks. I'm already cropping when needed off the 100, I think that 70 might be a step back too far.

I'm thinking the 70-200 range is more useful, especially once the weather warms up and there are more nature walks and zoo outings.

**rbefly** · 12-24-2011, 04:37 AM

Hi, Mr. Horrible,
I own the DA 50-200, it's not the fastest AF (focusing) zoom, but not the slowest, either. I'd say it's somewhere in the middle, in focusing speed and accuracy. The drawback to me is that it's pretty soft until f8.0 or so, even then it's not tack-sharp.
The fastest and most accurate focusing AF zoom (that I've personally used) in the Pentax badge is, hands down, the F 35-70mm. This little jewel racks to the AF point so fast you swear it's going to break something. But it just buzzes on, time after time. Makes quite a bit of racket doing so, but that's another story.
My next up in AF accuracy/speed is another "F", the 35-105mm f4-5.6, I owned one for awhile but ended up giving it to my sister, after buying the DA 50-200. Mistake, the F zoom was a much better lens overall, minus the "reach" of 200mm.
The 35-105mm has an AF rating of 9.3 on the lens review here and sells for an average of $73.29, a good deal in used lenses.
Almost as good as the F35-70mm for fifty bucks! Everyone should have one of those, just to compare AF performance. It's the benchmark.
JMO, Good luck...
Ron

yusuf · 12-24-2011, 10:17 PM

If you are fine with the weight, Tamron 70-200/2.8, no contest. Beautiful bokeh, sharper than 50-135 at wide open and no fear of SDM failure.

bassek · 12-25-2011, 10:42 AM

Once a scout I would suggest you not be changing lenses too much, hence a 28-75 (maybe with f2.8) or a slightly longer one like the F35-105 or F35-135 if you can find one. They AF really fast.
Or the DA18-250.

Seb.

Frogfish · 12-25-2011, 11:26 AM

1. If you can find one (and they do come up now and again - I've seen 2 or 3 come up on forums in the past 6-8 weeks - then there is no contest, the Sigma 50-150/2.8 is the lens you want. Lighter than the Tamron 70-200 and around the same size as the Pentax 50-135 but much faster focusing and HSM so no potential SDM issues, it's also very sharp wide open. That extra 20mm at the wide end is very useful whereas losing out 50mm at the long end isn't such a problem as you can easily crop to that FL FoV if you wish, it's so sharp that wouldn't be an issue.

2. Tamron 70-200/2.8 - it is fast focusing in low light conditions, very sharp and not as noisy as I thought it would be. Great lens.

3. Sigma 70-200/2.8 - HSM, if anything a touch faster than the Tamron, meaning very very fast, and just like the 50-150 it is silent (if that is a necessity) but not quite as sharp as the Tamron and costs a bit more.

I had the 55-300 but since I bought the 50-150 and 300 it has not been in use once, not once. It is clearly a level or two below them but still has great IQ. Where it loses out is in low light and focus hunting. Much much cheaper though.

**dadipentak** · 12-25-2011, 11:50 AM

Tammy 70-200/2.8 is a good option--also the Sigma 50-150/2.8.

Mister Horrible · 12-25-2011, 06:49 PM

Originally posted by bassek

Once a scout I would suggest you not be changing lenses too much, hence a 28-75 (maybe with f2.8) or a slightly longer one like the F35-105 or F35-135 if you can find one. They AF really fast.
Or the DA18-250.

Seb.

Anyone else have experience with the 35-135? I've already checked out the reviews at the lens database. If it focuses fast enough, the FL seems to be in the right range, and I could always slap it on my film camera. (Got 5 rolls of Ektar 100 for Christmas.) The only downside would probably be the aperture, which I don't think would be that big a deal.

I ask because if I move fairly quickly, I can likely get my mitts on one.

12-24-2011, 04:37 AM	#23
rbefly Site Supporter Join Date: Oct 2009 Location: Denver, Colorado Photos: Albums Posts: 2,030	An Oldie? Hi, Mr. Horrible, I own the DA 50-200, it's not the fastest AF (focusing) zoom, but not the slowest, either. I'd say it's somewhere in the middle, in focusing speed and accuracy. The drawback to me is that it's pretty soft until f8.0 or so, even then it's not tack-sharp. The fastest and most accurate focusing AF zoom (that I've personally used) in the Pentax badge is, hands down, the F 35-70mm. This little jewel racks to the AF point so fast you swear it's going to break something. But it just buzzes on, time after time. Makes quite a bit of racket doing so, but that's another story. My next up in AF accuracy/speed is another "F", the 35-105mm f4-5.6, I owned one for awhile but ended up giving it to my sister, after buying the DA 50-200. Mistake, the F zoom was a much better lens overall, minus the "reach" of 200mm. The 35-105mm has an AF rating of 9.3 on the lens review here and sells for an average of $73.29, a good deal in used lenses. Almost as good as the F35-70mm for fifty bucks! Everyone should have one of those, just to compare AF performance. It's the benchmark. JMO, Good luck... Ron

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Need some advice for a zoom lens	stang	Pentax SLR Lens Discussion	10	04-25-2011 01:24 AM
zoom on an autofocus lens	newpentaxman	Film SLRs and Compact Film Cameras	10	11-17-2010 01:57 AM
Shopping advice for fast manual ~35mm lens	bkhl	Pentax SLR Lens Discussion	4	08-10-2010 09:00 AM
Zoom telephoto lens advice	Gary G	Pentax SLR Lens Discussion	13	04-17-2010 10:45 AM
For Sale - Sold: Sigma Zoom Telephoto 100-300mm f/4 EX DG IF Autofocus Lens for Pentax AF	jgredline	Sold Items	7	02-04-2010 06:59 PM

12-20-2011, 01:21 PM	#16
dgaies Veteran Member Join Date: Oct 2009 Location: Maryland / Washington DC Posts: 3,917	Originally posted by Mister Horrible @Azzy, I don't think I'm parting w/ my 100 anytime soon. Do wish it had a focus limited on it, but love the bokeh and colors. I'm kind of agreeing that the Tammy 70-200 might be an option-- it would give me some versatility and supplement my other lenses in other areas as well. Am concerned that some reviews say it is slow focusing. Anyone have experience with the slower aperture lenses such as 50-200/55-300? I'm assumming their slow focusing as well. The Tamron 70-200/2.8 isn't too bad in terms of focusing speed. It's on par with the DA60-250/4. Something like the Sigma 70-200/2.8 HSM is going to be a bit faster, but I'd say the Tamron 70-200/2.8 (and DA60-250) have reasonable AF speed. Lenses like the 50-200 and 55-300 focuses fairly quickly in decent light, but tend to struggle a little more in low light because their max aperture is smaller. If you're considering one of them, I would recommend the 55-300 over the 50-200. It's optically better, and the extra reach is nice to have. The 55-300 is actually a very good value as compact consumer telephoto zooms go, so if you don't feel you need something faster, it's certainly an option worth considering.

12-20-2011, 01:52 PM	#17
Mister Horrible Senior Member Join Date: Aug 2008 Location: Rochester, NY Posts: 100 Original Poster	I'm thinking I need to start saving up for a Tammy 70-200. Thanks guys.

12-20-2011, 09:43 PM	#18
chickenandavocado Veteran Member Join Date: Oct 2010 Location: Hong Kong Posts: 327	Originally posted by DaveHolmes Tammy 90mm macro... Only ever used a friends on Canon but was very fast focusing! considering he already has the 100 macro i dont think its a good option the focus of the tamron is slow especially in low light, my recommendation is tamron 70-200

12-20-2011, 10:01 PM	#19
sterretje Veteran Member Join Date: Dec 2008 Location: Roodepoort, South Africa Photos: Gallery \| Albums Posts: 3,561	From experience, the DA55-300 can hunt as well; but I haven't tried it on a K5 (yet). No experience with 70-200, but you can research the Sigma 70-200/2.8 as well.

12-20-2011, 10:05 PM	#20
demp10 Veteran Member Join Date: Jun 2011 Location: Atlanta Photos: Albums Posts: 602	Originally posted by Mister Horrible Interesting ideas so far. I think the Pentax 35-70 might be a little two wide for what I am doing. The nice thing about the 100 is that I can "crop closer" and still have something decent enough for a 4x6 print. If your goal is to make 4x6 prints you can use practically any focal length down to 50mm, crop and still have enough pixels for an excellent print. All things being equal you need approximately about 8 MP for a 4x6. Anything beyond that and you need a magnifier to look at the pixels to see any differences. If you are budget sensitive, the F 35-50 is an absolute steal. The focus is practically instant with a very short travel. It is very decent wide open and stellar at F8. Besides it is very lightweight and very small so you'll not intimidate the kids.

12-20-2011, 11:33 PM	#21
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	I'll echo the suggestion of the small sharp agile F35-70, probably available by itself for around US$50. Use that whilst you're saving up for the Tammy 70-200. Ah, since you already have a K5, you could go pervy and get a Bigma 50-500. Just let ISO float as you shoot the near and the far. There is nothing like it.

12-21-2011, 06:06 AM	#22
Mister Horrible Senior Member Join Date: Aug 2008 Location: Rochester, NY Posts: 100 Original Poster	Thanks. I'm already cropping when needed off the 100, I think that 70 might be a step back too far. I'm thinking the 70-200 range is more useful, especially once the weather warms up and there are more nature walks and zoo outings.

12-24-2011, 10:17 PM	#24
yusuf Pentaxian Join Date: Nov 2008 Location: Palo Alto, CA Photos: Gallery Posts: 2,497	If you are fine with the weight, Tamron 70-200/2.8, no contest. Beautiful bokeh, sharper than 50-135 at wide open and no fear of SDM failure.

12-25-2011, 10:42 AM	#25
bassek Pentaxian Join Date: Feb 2011 Photos: Gallery Posts: 706	Once a scout I would suggest you not be changing lenses too much, hence a 28-75 (maybe with f2.8) or a slightly longer one like the F35-105 or F35-135 if you can find one. They AF really fast. Or the DA18-250. Seb.

12-25-2011, 11:26 AM	#26
Frogfish Veteran Member Join Date: Dec 2009 Location: Shanghai Posts: 4,490	1. If you can find one (and they do come up now and again - I've seen 2 or 3 come up on forums in the past 6-8 weeks - then there is no contest, the Sigma 50-150/2.8 is the lens you want. Lighter than the Tamron 70-200 and around the same size as the Pentax 50-135 but much faster focusing and HSM so no potential SDM issues, it's also very sharp wide open. That extra 20mm at the wide end is very useful whereas losing out 50mm at the long end isn't such a problem as you can easily crop to that FL FoV if you wish, it's so sharp that wouldn't be an issue. 2. Tamron 70-200/2.8 - it is fast focusing in low light conditions, very sharp and not as noisy as I thought it would be. Great lens. 3. Sigma 70-200/2.8 - HSM, if anything a touch faster than the Tamron, meaning very very fast, and just like the 50-150 it is silent (if that is a necessity) but not quite as sharp as the Tamron and costs a bit more. I had the 55-300 but since I bought the 50-150 and 300 it has not been in use once, not once. It is clearly a level or two below them but still has great IQ. Where it loses out is in low light and focus hunting. Much much cheaper though.

Thread Tools	Search this Thread
	Search this Thread: Advanced Search

12-25-2011, 11:50 AM	#27
dadipentak Site Supporter Join Date: Jul 2008 Location: Baltimore, Maryland Photos: Gallery Posts: 11,590	Tammy 70-200/2.8 is a good option--also the Sigma 50-150/2.8.

12-25-2011, 06:49 PM	#28
Mister Horrible Senior Member Join Date: Aug 2008 Location: Rochester, NY Posts: 100 Original Poster	Originally posted by bassek Once a scout I would suggest you not be changing lenses too much, hence a 28-75 (maybe with f2.8) or a slightly longer one like the F35-105 or F35-135 if you can find one. They AF really fast. Or the DA18-250. Seb. Anyone else have experience with the 35-135? I've already checked out the reviews at the lens database. If it focuses fast enough, the FL seems to be in the right range, and I could always slap it on my film camera. (Got 5 rolls of Ektar 100 for Christmas.) The only downside would probably be the aperture, which I don't think would be that big a deal. I ask because if I move fairly quickly, I can likely get my mitts on one.