Pentax 55-300WR on K50 and K3

Setter Dog · 03-03-2015, 12:31 PM

Hi Folks,

I've posted on the DP Review forum and thought I'd also post about my problem over here.

I'm very new to Pentax and really, really like both my K50 and K3. I also like the 18-135mm WR on either camera. My problem is with the 55-300mm WR. In many ways, I really like the lens. It's pretty sharp, beautifully built, good colors, and fun to use,.......but only in good light. Early morning shooting is not fun. The focus hunting is very annoying. I've learned that this is "fairly normal" with this lens and members have various work arounds they use. I've tried the trick of manually focusing at infinity and letting the AF come inward. Supposed to be a little faster. Well, I guess it is. It just seems to me that we shouldn't have to struggle to get focus.

I can still return the lens. Does anyone use the Sigma 18-250mm macro, the similar Tamron, or any other zoom options over 250mm? Thanks for any suggestions.

Jack

Adam · 03-03-2015, 12:45 PM

I'd recommend considering upgrading to the K-S2 or K-5 II. Those cameras have newer AF systems that focus considerably faster and more accurately in poor light. You can expect other consumer telephoto zooms or superzooms to deliver similar performance to the 55-300mm, since most are in the F5.6-6.3 range at the long end.

**UncleVanya** · 03-03-2015, 12:50 PM

Originally posted by Adam

I'd recommend considering upgrading to the K-S2 or K-5 II. Those cameras have newer AF systems that focus considerably faster and more accurately in poor light. You can expect other consumer telephoto zooms or superzooms to deliver similar performance to the 55-300mm, since most are in the F5.6-6.3 range at the long end.

I didn't realize that K5-II had newer/better AF than the K3 - I thought the opposite was true. Thanks for that info Adam.

Adam · 03-03-2015, 12:58 PM

Originally posted by UncleVanya

I didn't realize that K5-II had newer/better AF than the K3 - I thought the opposite was true. Thanks for that info Adam.

I misread the post and/or there was a typo. Thought it said K-30!

The low-light performance of the K-3 is better than that of the K-50, same as that of the K-5 II and K-S2.

Adam
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**UncleVanya** · 03-03-2015, 01:07 PM

Originally posted by Adam

I misread the post and/or there was a typo. Thought it said K-30!

The low-light performance of the K-3 is better than that of the K-50, same as that of the K-5 II and K-S2.

Ooops. Well that was more in line with what I thought I knew so my head isn't spinning around anymore. I haven't heard of a lot of problems with 55-300 focus. I can try mine on my K50 which isn't as advanced as the K3 I don't believe.

---------- Post added 03-03-15 at 03:36 PM ----------

I just tried with my K50 and my DA 55-300 (SMC version) and I had no problems focusing indoors with minimal light from overcast day. I also went into my garage which is very dark (dark walls minimal windows) and had no problems there. To put in perspective:

Indoor shots were at f/5.8 300mm 1/10sec at ISO 3200 and f/4.5 55mm 1/13s - 1/25s ISO 3200
All shots acquired focus quickly without problems. I can post the shots (they are pretty lousy - just trying to get focus confirmation) if desired.

EDIT:

OP - what rough exposure level is this happening at? ISO, F/stop, Shutter speed? I don't have any ND filters or a CPL in 58mm that I can recall so reducing light levels will have to wait until dusk tonight.

audiobomber · 03-03-2015, 01:54 PM

Originally posted by Adam

I misread the post and/or there was a typo. Thought it said K-30!

The low-light performance of the K-3 is better than that of the K-50, same as that of the K-5 II and K-S2.

Theoretically the K-3 should be best because it has three f/2.8 sensitive AF points, vs. one f2.8 AF point in the K-5 II and K-S2.

I agree with UncleVanya, the 55-300 should not be having this much difficulty finding focus, even in dim light. It is actually pretty good on the K-3, I don't recall it hunting at all and I'm using it a lot. I did have some trouble with my old K20D and 55-300 though.

I suspect the lens is defective, or needs AF calibration. My worst lens for AF hunting is the DA 18-250mm.

**savoche** · 03-03-2015, 02:14 PM

My SMC DA 55-300 focuses better on the K-3 than the (classic) K-5 under all lighting conditions. It still hunts now and then, but by the time it gets too dark to lock focus at all I would probably need ISO 12800 or more to get a good exposure anyway.

I find it perfectly usable in open landscapes even after sunset, but I really wished for something faster (and faster focusing) in the rainforest.

**UncleVanya** · 03-03-2015, 02:40 PM

When the OP posts exposure info I will try to replicate - I have the same K50 body and the SMC version of the lens. I also have a 60-250 f/4 that I can try after to see if it fares any differently.

Setter Dog · 03-03-2015, 02:54 PM

Originally posted by UncleVanya

When the OP posts exposure info I will try to replicate - I have the same K50 body and the SMC version of the lens. I also have a 60-250 f/4 that I can try after to see if it fares any differently.

It's nice of you members to try and help. I'm becoming convinced that I have a bad copy of the lens, especially since the focus is not noticeably faster on my K3. Of the shots I kept from this morning, with the K3, both of them were at 1/250th, F5.6, ISO200 and 210mm(315 equiv). As you can tell, it wasn't exactly low light shooting,.....

Jack

**UncleVanya** · 03-03-2015, 02:57 PM

Originally posted by Setter Dog

It's nice of you members to try and help. I'm becoming convinced that I have a bad copy of the lens, especially since the focus is not noticeably faster on my K3. Of the shots I kept from this morning, with the K3, both of them were at 1/250th, F5.6, ISO200 and 210mm(315 equiv). As you can tell, it wasn't exactly low light shooting,.....

Jack

WOW... yup. That's terrible if you could not get focus. I am not seeing anything like that. I will be happy to post shots or video if you need it but that's just not what the lens is capable of. My copy is reasonably quick and well behaved at even dusk. Too dark a subject, or a low contrast subject and things go south fast but that's the same for any lens on these cameras. What was your subject?

Imp · 03-03-2015, 03:22 PM

My copy can hunt, but it isn't terrible. I did have to do -3 sometimes -5 focus compensation, but it works relatively fine. I've shot a basketball game with it, not the brightest conditions, it worked fine.

**UncleVanya** · 03-03-2015, 03:26 PM

Originally posted by Imp

My copy can hunt, but it isn't terrible. I did have to do -3 sometimes -5 focus compensation, but it works relatively fine. I've shot a basketball game with it, not the brightest conditions, it worked fine.

Clear something up for me. Do AF adjustments only impact WHERE it focuses or also how well it focus locks? I've seen confusing info but I think the former is correct and hunting isn't related to back/front focus but I'm not 100% certain.

CNunez · 03-03-2015, 03:27 PM

I was intrigued and decided to test this myself. I compared the 55-300wr to the 50/1.8. Not sure if they are two good lenses to compare. Anyway.

K3 + 55-300 (300/5.8) iso 6400 vs 50/1.8 same iso.

I found that they lock on exactly the same. I'm standing in my room, light switched off. There's a full moon outside dimly lighting up the trees.

Anyway. They both require some good contrast to lock on. I was first using centre point single focus point. Lock on was possible on light objects, however I just made it hard on myself looking through a dark viewfinder.

Once I used auto 27, it found something to lock on to much quicker. A tall birch tree in the neighbor's garden was 100% lock on.

I experienced a full focus throw on both lenses before locking on a few times when I was being silly and trying to pick out detail I couldn't make it myself.

I also tried using quick shift to pre focus, again it depends entirely on the visible contrast of the subject.

Imp · 03-03-2015, 04:01 PM

Originally posted by UncleVanya

WHERE it focuses

Only where it focuses. I.E, for me it would focus a bit beyond the point I wanted it to, so i did a minus adjustment and fixed it

Setter Dog · 03-03-2015, 04:37 PM

Originally posted by Imp

Only where it focuses. I.E, for me it would focus a bit beyond the point I wanted it to, so i did a minus adjustment and fixed it

Hi Folks,....I decided I had a bad lens and will be returning it. I simply don't see how a normal lens could be so bad compared to my 18-135mm WR, which is just fine. I really like my Pentax cameras and this lens was taking some of the fun out of my photography. Not sure what I'll try next. I love my 18-135mm and may go all the way to one of the big Sigmas, like the 150-500, later if I feel the zoom urge again.

Thanks again to those of you that tried to help and encouraged me. This is a good friendly forum. I plan to be around a long time.

Jack

03-03-2015, 12:31 PM	#1
Setter Dog Senior Member Join Date: Feb 2015 Location: Orange County California Posts: 117	Pentax 55-300WR on K50 and K3 Hi Folks, I've posted on the DP Review forum and thought I'd also post about my problem over here. I'm very new to Pentax and really, really like both my K50 and K3. I also like the 18-135mm WR on either camera. My problem is with the 55-300mm WR. In many ways, I really like the lens. It's pretty sharp, beautifully built, good colors, and fun to use,.......but only in good light. Early morning shooting is not fun. The focus hunting is very annoying. I've learned that this is "fairly normal" with this lens and members have various work arounds they use. I've tried the trick of manually focusing at infinity and letting the AF come inward. Supposed to be a little faster. Well, I guess it is. It just seems to me that we shouldn't have to struggle to get focus. I can still return the lens. Does anyone use the Sigma 18-250mm macro, the similar Tamron, or any other zoom options over 250mm? Thanks for any suggestions. Jack

03-03-2015, 12:45 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	I'd recommend considering upgrading to the K-S2 or K-5 II. Those cameras have newer AF systems that focus considerably faster and more accurately in poor light. You can expect other consumer telephoto zooms or superzooms to deliver similar performance to the 55-300mm, since most are in the F5.6-6.3 range at the long end. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-03-2015, 01:07 PM	#5
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by Adam I misread the post and/or there was a typo. Thought it said K-30! The low-light performance of the K-3 is better than that of the K-50, same as that of the K-5 II and K-S2. Ooops. Well that was more in line with what I thought I knew so my head isn't spinning around anymore. I haven't heard of a lot of problems with 55-300 focus. I can try mine on my K50 which isn't as advanced as the K3 I don't believe. ---------- Post added 03-03-15 at 03:36 PM ---------- I just tried with my K50 and my DA 55-300 (SMC version) and I had no problems focusing indoors with minimal light from overcast day. I also went into my garage which is very dark (dark walls minimal windows) and had no problems there. To put in perspective: Indoor shots were at f/5.8 300mm 1/10sec at ISO 3200 and f/4.5 55mm 1/13s - 1/25s ISO 3200 All shots acquired focus quickly without problems. I can post the shots (they are pretty lousy - just trying to get focus confirmation) if desired. EDIT: OP - what rough exposure level is this happening at? ISO, F/stop, Shutter speed? I don't have any ND filters or a CPL in 58mm that I can recall so reducing light levels will have to wait until dusk tonight. Last edited by UncleVanya; 03-03-2015 at 01:38 PM.

03-03-2015, 01:54 PM	#6
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by Adam I misread the post and/or there was a typo. Thought it said K-30! The low-light performance of the K-3 is better than that of the K-50, same as that of the K-5 II and K-S2. Theoretically the K-3 should be best because it has three f/2.8 sensitive AF points, vs. one f2.8 AF point in the K-5 II and K-S2. I agree with UncleVanya, the 55-300 should not be having this much difficulty finding focus, even in dim light. It is actually pretty good on the K-3, I don't recall it hunting at all and I'm using it a lot. I did have some trouble with my old K20D and 55-300 though. I suspect the lens is defective, or needs AF calibration. My worst lens for AF hunting is the DA 18-250mm. Last edited by audiobomber; 03-03-2015 at 02:33 PM.

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03-03-2015, 12:50 PM	#3
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by Adam I'd recommend considering upgrading to the K-S2 or K-5 II. Those cameras have newer AF systems that focus considerably faster and more accurately in poor light. You can expect other consumer telephoto zooms or superzooms to deliver similar performance to the 55-300mm, since most are in the F5.6-6.3 range at the long end. I didn't realize that K5-II had newer/better AF than the K3 - I thought the opposite was true. Thanks for that info Adam.

03-03-2015, 12:58 PM	#4
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Originally posted by UncleVanya I didn't realize that K5-II had newer/better AF than the K3 - I thought the opposite was true. Thanks for that info Adam. I misread the post and/or there was a typo. Thought it said K-30! The low-light performance of the K-3 is better than that of the K-50, same as that of the K-5 II and K-S2. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-03-2015, 02:14 PM	#7
savoche Master of the obvious Join Date: Jun 2011 Location: Lowlands of Norway Posts: 18,311	My SMC DA 55-300 focuses better on the K-3 than the (classic) K-5 under all lighting conditions. It still hunts now and then, but by the time it gets too dark to lock focus at all I would probably need ISO 12800 or more to get a good exposure anyway. I find it perfectly usable in open landscapes even after sunset, but I really wished for something faster (and faster focusing) in the rainforest.

03-03-2015, 02:40 PM	#8
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	When the OP posts exposure info I will try to replicate - I have the same K50 body and the SMC version of the lens. I also have a 60-250 f/4 that I can try after to see if it fares any differently.

03-03-2015, 02:54 PM	#9
Setter Dog Senior Member Join Date: Feb 2015 Location: Orange County California Posts: 117 Original Poster	Originally posted by UncleVanya When the OP posts exposure info I will try to replicate - I have the same K50 body and the SMC version of the lens. I also have a 60-250 f/4 that I can try after to see if it fares any differently. It's nice of you members to try and help. I'm becoming convinced that I have a bad copy of the lens, especially since the focus is not noticeably faster on my K3. Of the shots I kept from this morning, with the K3, both of them were at 1/250th, F5.6, ISO200 and 210mm(315 equiv). As you can tell, it wasn't exactly low light shooting,..... Jack

03-03-2015, 02:57 PM	#10
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by Setter Dog It's nice of you members to try and help. I'm becoming convinced that I have a bad copy of the lens, especially since the focus is not noticeably faster on my K3. Of the shots I kept from this morning, with the K3, both of them were at 1/250th, F5.6, ISO200 and 210mm(315 equiv). As you can tell, it wasn't exactly low light shooting,..... Jack WOW... yup. That's terrible if you could not get focus. I am not seeing anything like that. I will be happy to post shots or video if you need it but that's just not what the lens is capable of. My copy is reasonably quick and well behaved at even dusk. Too dark a subject, or a low contrast subject and things go south fast but that's the same for any lens on these cameras. What was your subject?

03-03-2015, 03:22 PM	#11
Imp Pentaxian Join Date: Nov 2014 Location: Washington, DC Photos: Gallery \| Albums Posts: 1,749	My copy can hunt, but it isn't terrible. I did have to do -3 sometimes -5 focus compensation, but it works relatively fine. I've shot a basketball game with it, not the brightest conditions, it worked fine.

03-03-2015, 03:26 PM	#12
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	Originally posted by Imp My copy can hunt, but it isn't terrible. I did have to do -3 sometimes -5 focus compensation, but it works relatively fine. I've shot a basketball game with it, not the brightest conditions, it worked fine. Clear something up for me. Do AF adjustments only impact WHERE it focuses or also how well it focus locks? I've seen confusing info but I think the former is correct and hunting isn't related to back/front focus but I'm not 100% certain.

03-03-2015, 03:27 PM	#13
CNunez Senior Member Join Date: Dec 2014 Photos: Gallery Posts: 168	I was intrigued and decided to test this myself. I compared the 55-300wr to the 50/1.8. Not sure if they are two good lenses to compare. Anyway. K3 + 55-300 (300/5.8) iso 6400 vs 50/1.8 same iso. I found that they lock on exactly the same. I'm standing in my room, light switched off. There's a full moon outside dimly lighting up the trees. Anyway. They both require some good contrast to lock on. I was first using centre point single focus point. Lock on was possible on light objects, however I just made it hard on myself looking through a dark viewfinder. Once I used auto 27, it found something to lock on to much quicker. A tall birch tree in the neighbor's garden was 100% lock on. I experienced a full focus throw on both lenses before locking on a few times when I was being silly and trying to pick out detail I couldn't make it myself. I also tried using quick shift to pre focus, again it depends entirely on the visible contrast of the subject.

03-03-2015, 04:01 PM	#14
Imp Pentaxian Join Date: Nov 2014 Location: Washington, DC Photos: Gallery \| Albums Posts: 1,749	Originally posted by UncleVanya WHERE it focuses Only where it focuses. I.E, for me it would focus a bit beyond the point I wanted it to, so i did a minus adjustment and fixed it

03-03-2015, 04:37 PM	#15
Setter Dog Senior Member Join Date: Feb 2015 Location: Orange County California Posts: 117 Original Poster	Originally posted by Imp Only where it focuses. I.E, for me it would focus a bit beyond the point I wanted it to, so i did a minus adjustment and fixed it Hi Folks,....I decided I had a bad lens and will be returning it. I simply don't see how a normal lens could be so bad compared to my 18-135mm WR, which is just fine. I really like my Pentax cameras and this lens was taking some of the fun out of my photography. Not sure what I'll try next. I love my 18-135mm and may go all the way to one of the big Sigmas, like the 150-500, later if I feel the zoom urge again. Thanks again to those of you that tried to help and encouraged me. This is a good friendly forum. I plan to be around a long time. Jack