18-135 WR Severe Back Focus on K-30

dcpropilot · 05-12-2014, 04:49 AM

I did a focus check after some really out of focus shots and it appears that this lens is back focusing quite a bit on my K-30. All my other lens do not present such a problem. I have it almost corrected but ran out of available adjustment, Right now, it's at +10, and it looks like another 2 or 3 is needed to get it perfect. Is this something that needs to get sent back for 'calibration'? I've never done this before and just curious if this is an appropriate course of action.
Thanks!

stormtech · 05-12-2014, 05:12 AM

There are a couple courses of action.

If you bought it new and less than 30 days ago, return it to the vendor and ask for an exchange for a different one.

If bought new and more than 30 days but less than 1 year, send it off to CRIS. You have 2 options here. You can send the lens alone and they will adjust/calibrate it to a master camera they have that is known for good AF adjustment. Or you can send your camera in with the lens and they will adjust/calibrate your lens and camera together.

If out of warranty, you can still send it in to CRIS. They will evaluate the lens and contact you with a quote before they do any work. Then you can either pay the quote, or deny it which they will then send the lens back to you.

audiobomber · 05-12-2014, 05:12 AM

Originally posted by dcpropilot

I did a focus check after some really out of focus shots and it appears that this lens is back focusing quite a bit on my K-30. All my other lens do not present such a problem. I have it almost corrected but ran out of available adjustment, Right now, it's at +10, and it looks like another 2 or 3 is needed to get it perfect. Is this something that needs to get sent back for 'calibration'? I've never done this before and just curious if this is an appropriate course of action.
Thanks!

Definitely send it back. My 18-135 needed +10 for accurate focus. I used it like that for a few months before sending it back, because I needed it for my Paris trip.

If a lens is out of calibration, I return it. As a result, I don't need AF Adjust for any of my lenses. A lens that is back-focussing can cause a problem if you ever sell it, or if you ever buy a camera without individual lens calibration (e.g. K100D, K-2000, K200D, K-x, K-r, K-01).

JohnX · 05-12-2014, 05:48 AM

It's the combination of the manufacturing tolerances of both the body and lens that cause the problem. Either can be said to be 'out of calibration' whilst at the same time being within tolerance. Normally changing one will cure the problem.

I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'.

Wish I was that lucky.

Last edited by JohnX; 05-12-2014 at 08:49 AM.

Al_T · 05-12-2014, 06:18 AM

I purchased a Lens Align which gives me an accurate visual method to adjust my lenses. It is amazing how much sharper my images have become. All of my lenses needed some adjustment Most were just + or - 2 or 3 at the maximum except for my DA18-135 which took +7 to get rid of the back focus. For a super zoom lens it is super sharp now. If you are that far out I would send the lens back for adjustment.

lesmore49 · 05-12-2014, 06:25 AM

Originally posted by JohnX

It's the combination of the manufacturing tolerances of both the body and lens that cause the problem. Either can be said to be 'out of calibration' whilst at the same time being with tolerance. Normally changing one will cure the problem.

I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'.

Wish I was that lucky.

I've got 10 Pentax digital lenses, 3 bodies and with the exception of one lens....they have not needed adjustment. I'm also a bit of a pixel peeper and so far I've also been lucky I suppose. Hope my luck continues.

audiobomber · 05-12-2014, 08:42 AM

Originally posted by JohnX

It's the combination of the manufacturing tolerances of both the body and lens that cause the problem. Either can be said to be 'out of calibration' whilst at the same time being with tolerance. Normally changing one will cure the problem.

I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'.

Wish I was that lucky.

Note that the OP said: "All my other lens do not present such a problem." The obvious answer is to return the lens under warranty.

I've owned a K100D Super, K20D, K-x, K-5, K-01 and K-3. The only body that was off in daylight was the K-x and I did a universal adjustment on it. The K-5 could not focus accurately in tungsten light so I sent it back to the store, never to return.

Pentax Canada asks for a camera with the lens so they can calibrate both. The K20D has been there a couple of times and the K-x too. I sent back a DA 15mm Ltd (needed +3), FA 35 (needed +6), and 18-135mm (+10). The first DA*300 was back-focussing, but I asked the dealer for exchange rather than calibration because I wasn't comfortable with the SDM performance. The new DA*300 focus was a bit off, and I returned it to Pentax for calibration. Now it's bang on.

All of the preceding were fixed in the warranty period except for the FA 35. Pentax Canada charged me $107 to calibrate. I returned an F 28mm to KEH for a refund. It was back-focussing so badly it couldn't be fixed with AF Adjust, and the cost to calibrate wasn't worthwhile to me. My new HD 1.4x RC is back-focussing. I will return it when convenient. My situation has more to do with insistence and persistence than luck.

dcpropilot · 05-12-2014, 01:21 PM

I sent it to Pentax today. Actually, the improvements that I had made using the fine adjustment at +10 was close (maybe a couple more to be perfect). Hopefully they can reset it zero. Not sure what is done for the calibration but it's well worth it. Hopefully the turnaround isn't too bad. All this time, I was accepting 'soft' as being an attribute of the lens.

Thanks everyone!

nosliwmit · 05-13-2014, 10:54 AM

Hi. I have a DA*300 that back-focuses rather badly on my K-5. I ended up setting the lens-specific adjustment at 10 (can't remember if it was + or -) and then added an additional 2 using the universal adjustment (applies to all lenses) which, in theory, should have resulted in a 12-point adjustment. Then I canceled out that universal 2 point adjustment on all of my other lenses by setting each of them to 2 points in the opposite direction. It seemed to work, but to be honest I usually manually focus the DA*300 and haven't 100% convinced myself that the overall and lens-specific adjustments truly add up or if 10 is a hard limit... If anyone has done any complementary research I'd be interested!

ruben · 05-18-2014, 11:38 PM

How did you measure the deviation of your autofocus?

My Pentax K-7D had a similar backfocussing. I adjusted it in the fine adjustment using spyder lenscal as a reference.
For small deviations this helps to correct to 0, without having to send to the manufacturer and wait for my body.

dcpropilot · 06-06-2014, 03:33 PM

I got my 18-135WR back from C.R.I.S./Pentax today, I had to pay for the calibration since my lens was purchased new from a ebay retailer that isn't authorized Pentax retailer (learned my lesson for next time I make a purchase). The lens came back absolutely perfect. I am now really enjoying this lens. I wonder how much calibration lenses get when done at the factory. Would have saved me time and money had it been done in the first place. Anyway, I am now very happy with my investment.

**seventysixersfan** · 06-06-2014, 07:53 PM

Do you mind revealing how much you had to pay for the calibration?

stevebrot · 06-07-2014, 10:04 AM

Originally posted by JohnX

I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'.

Wish I was that lucky.

My experience has been the same as Dan's, minus sending all the lenses back. I have not had any back-focus/front-focus issues with my AF lenses. That being said, it is my opinion that there is a general over-sensitivity on the matter of PDAF focus adjustment. I may yet adjust a couple of my AF lenses when I am in a particularly anal-retentive mood, but probably not before. You see, I don't depend on the AF system for delivering fine focus where focus is critical. It was never designed for that task and as a result sucks at it. I guess, my expectations are fairly low. I check my lens PDAF performance against magnified live view with focus peaking using a flat, high contrast target. If I cannot improve on the PDAF result in live view, I call it good.

The OP, OTOH, definitely had a problem and a service call was the appropriate and happy solution. The OP's copy of the 18-135 constituted an "outlier" in the classic sense of the term.

Steve

audiobomber · 06-07-2014, 11:35 AM

Originally posted by seventysixersfan

Do you mind revealing how much you had to pay for the calibration?

The only lens I sent back that wasn't under warranty was the FA 35mm. I paid $107 to Pentax Canada for calibration.

dcpropilot · 06-08-2014, 05:02 AM - **1 Like**

I paid $70 for calibration plus shipping. Well worth it to me.

05-12-2014, 04:49 AM	#1
dcpropilot Veteran Member Join Date: Mar 2010 Location: Vermont Photos: Gallery \| Albums Posts: 941	18-135 WR Severe Back Focus on K-30 I did a focus check after some really out of focus shots and it appears that this lens is back focusing quite a bit on my K-30. All my other lens do not present such a problem. I have it almost corrected but ran out of available adjustment, Right now, it's at +10, and it looks like another 2 or 3 is needed to get it perfect. Is this something that needs to get sent back for 'calibration'? I've never done this before and just curious if this is an appropriate course of action. Thanks!

06-07-2014, 10:04 AM	#13
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by JohnX I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'. Wish I was that lucky. My experience has been the same as Dan's, minus sending all the lenses back. I have not had any back-focus/front-focus issues with my AF lenses. That being said, it is my opinion that there is a general over-sensitivity on the matter of PDAF focus adjustment. I may yet adjust a couple of my AF lenses when I am in a particularly anal-retentive mood, but probably not before. You see, I don't depend on the AF system for delivering fine focus where focus is critical. It was never designed for that task and as a result sucks at it. I guess, my expectations are fairly low. I check my lens PDAF performance against magnified live view with focus peaking using a flat, high contrast target. If I cannot improve on the PDAF result in live view, I call it good. The OP, OTOH, definitely had a problem and a service call was the appropriate and happy solution. The OP's copy of the 18-135 constituted an "outlier" in the classic sense of the term. Steve Last edited by stevebrot; 06-07-2014 at 10:58 AM.

06-07-2014, 11:35 AM	#14
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by seventysixersfan Do you mind revealing how much you had to pay for the calibration? The only lens I sent back that wasn't under warranty was the FA 35mm. I paid $107 to Pentax Canada for calibration. Last edited by audiobomber; 06-08-2014 at 05:26 AM.

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05-12-2014, 05:12 AM	#2
stormtech Veteran Member Join Date: Jan 2011 Location: In the boonies (NW Penna) Photos: Gallery \| Albums Posts: 5,744	There are a couple courses of action. If you bought it new and less than 30 days ago, return it to the vendor and ask for an exchange for a different one. If bought new and more than 30 days but less than 1 year, send it off to CRIS. You have 2 options here. You can send the lens alone and they will adjust/calibrate it to a master camera they have that is known for good AF adjustment. Or you can send your camera in with the lens and they will adjust/calibrate your lens and camera together. If out of warranty, you can still send it in to CRIS. They will evaluate the lens and contact you with a quote before they do any work. Then you can either pay the quote, or deny it which they will then send the lens back to you.

05-12-2014, 05:12 AM	#3
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by dcpropilot I did a focus check after some really out of focus shots and it appears that this lens is back focusing quite a bit on my K-30. All my other lens do not present such a problem. I have it almost corrected but ran out of available adjustment, Right now, it's at +10, and it looks like another 2 or 3 is needed to get it perfect. Is this something that needs to get sent back for 'calibration'? I've never done this before and just curious if this is an appropriate course of action. Thanks! Definitely send it back. My 18-135 needed +10 for accurate focus. I used it like that for a few months before sending it back, because I needed it for my Paris trip. If a lens is out of calibration, I return it. As a result, I don't need AF Adjust for any of my lenses. A lens that is back-focussing can cause a problem if you ever sell it, or if you ever buy a camera without individual lens calibration (e.g. K100D, K-2000, K200D, K-x, K-r, K-01).

05-12-2014, 05:48 AM	#4
JohnX Pentaxian Join Date: Jul 2009 Location: London Posts: 1,116	It's the combination of the manufacturing tolerances of both the body and lens that cause the problem. Either can be said to be 'out of calibration' whilst at the same time being within tolerance. Normally changing one will cure the problem. I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'. Wish I was that lucky. Last edited by JohnX; 05-12-2014 at 08:49 AM.

05-12-2014, 06:18 AM	#5
Al_T Inactive Account Join Date: Oct 2010 Location: Texas Photos: Gallery Posts: 33	I purchased a Lens Align which gives me an accurate visual method to adjust my lenses. It is amazing how much sharper my images have become. All of my lenses needed some adjustment Most were just + or - 2 or 3 at the maximum except for my DA18-135 which took +7 to get rid of the back focus. For a super zoom lens it is super sharp now. If you are that far out I would send the lens back for adjustment.

05-12-2014, 06:25 AM	#6
lesmore49 Pentaxian Join Date: Nov 2007 Location: Western Canada Posts: 12,337	Originally posted by JohnX It's the combination of the manufacturing tolerances of both the body and lens that cause the problem. Either can be said to be 'out of calibration' whilst at the same time being with tolerance. Normally changing one will cure the problem. I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'. Wish I was that lucky. I've got 10 Pentax digital lenses, 3 bodies and with the exception of one lens....they have not needed adjustment. I'm also a bit of a pixel peeper and so far I've also been lucky I suppose. Hope my luck continues.

05-12-2014, 08:42 AM	#7
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	Originally posted by JohnX It's the combination of the manufacturing tolerances of both the body and lens that cause the problem. Either can be said to be 'out of calibration' whilst at the same time being with tolerance. Normally changing one will cure the problem. I'm amazed, Dan, that you don't need any AF adjustment for any of your lenses, although I have read this once or twice before, as it implies that all your lenses have exactly the same and opposite manufacturing tolerance as your camera body, or they are all '0'. Wish I was that lucky. Note that the OP said: "All my other lens do not present such a problem." The obvious answer is to return the lens under warranty. I've owned a K100D Super, K20D, K-x, K-5, K-01 and K-3. The only body that was off in daylight was the K-x and I did a universal adjustment on it. The K-5 could not focus accurately in tungsten light so I sent it back to the store, never to return. Pentax Canada asks for a camera with the lens so they can calibrate both. The K20D has been there a couple of times and the K-x too. I sent back a DA 15mm Ltd (needed +3), FA 35 (needed +6), and 18-135mm (+10). The first DA300 was back-focussing, but I asked the dealer for exchange rather than calibration because I wasn't comfortable with the SDM performance. The new DA300 focus was a bit off, and I returned it to Pentax for calibration. Now it's bang on. All of the preceding were fixed in the warranty period except for the FA 35. Pentax Canada charged me $107 to calibrate. I returned an F 28mm to KEH for a refund. It was back-focussing so badly it couldn't be fixed with AF Adjust, and the cost to calibrate wasn't worthwhile to me. My new HD 1.4x RC is back-focussing. I will return it when convenient. My situation has more to do with insistence and persistence than luck.

05-12-2014, 01:21 PM	#8
dcpropilot Veteran Member Join Date: Mar 2010 Location: Vermont Photos: Gallery \| Albums Posts: 941 Original Poster	I sent it to Pentax today. Actually, the improvements that I had made using the fine adjustment at +10 was close (maybe a couple more to be perfect). Hopefully they can reset it zero. Not sure what is done for the calibration but it's well worth it. Hopefully the turnaround isn't too bad. All this time, I was accepting 'soft' as being an attribute of the lens. Thanks everyone!

05-13-2014, 10:54 AM	#9
nosliwmit Pentaxian Join Date: Nov 2010 Location: Pacific Northwest Photos: Gallery Posts: 913	Hi. I have a DA300 that back-focuses rather badly on my K-5. I ended up setting the lens-specific adjustment at 10 (can't remember if it was + or -) and then added an additional 2 using the universal adjustment (applies to all lenses) which, in theory, should have resulted in a 12-point adjustment. Then I canceled out that universal 2 point adjustment on all of my other lenses by setting each of them to 2 points in the opposite direction. It seemed to work, but to be honest I usually manually focus the DA300 and haven't 100% convinced myself that the overall and lens-specific adjustments truly add up or if 10 is a hard limit... If anyone has done any complementary research I'd be interested!

05-18-2014, 11:38 PM	#10
ruben Inactive Account Join Date: May 2014 Posts: 21	How did you measure the deviation of your autofocus? My Pentax K-7D had a similar backfocussing. I adjusted it in the fine adjustment using spyder lenscal as a reference. For small deviations this helps to correct to 0, without having to send to the manufacturer and wait for my body.

06-06-2014, 03:33 PM	#11
dcpropilot Veteran Member Join Date: Mar 2010 Location: Vermont Photos: Gallery \| Albums Posts: 941 Original Poster	I got my 18-135WR back from C.R.I.S./Pentax today, I had to pay for the calibration since my lens was purchased new from a ebay retailer that isn't authorized Pentax retailer (learned my lesson for next time I make a purchase). The lens came back absolutely perfect. I am now really enjoying this lens. I wonder how much calibration lenses get when done at the factory. Would have saved me time and money had it been done in the first place. Anyway, I am now very happy with my investment.

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06-06-2014, 07:53 PM	#12
seventysixersfan Site Supporter Join Date: Aug 2010 Location: Alexandria, VA Posts: 2,054	Do you mind revealing how much you had to pay for the calibration?

06-08-2014, 05:02 AM - 1 Like	#15
dcpropilot Veteran Member Join Date: Mar 2010 Location: Vermont Photos: Gallery \| Albums Posts: 941 Original Poster	I paid $70 for calibration plus shipping. Well worth it to me.