Win a Pentax Limited Lens: Raffle Now Live!

totsmuyco · 12-02-2017, 04:45 AM

Is there a guide on how to calibrate zoom lenses? I think my HD 55-300 might need some calibration. Thanks.

**UncleVanya** · 12-02-2017, 07:23 AM

Originally posted by totsmuyco

Is there a guide on how to calibrate zoom lenses? I think my HD 55-300 might need some calibration. Thanks.

You do the same process as for a prime. But you have to pick a focal length, and love with any inaccuracy driven by that.

35mmfilmfan · 12-02-2017, 07:29 AM

When I did mine, I checked both ends of the zoom range, and if they differed, I did the adjustment to be nearer the telephoto end, to take account of DOF.

**BarryE** · 12-02-2017, 11:53 AM

My pennies worth: Measure the adjustment throughout the range. You might find one end differs a lot more than the rest- this may influence what you choose. Then consider where you want the most accuracy to be, either by most frequently used FL use or where you want the accuracy to be. Measurements and preferences will get you close(ish). Add in field curvature and variations between near and far focus and you're unlikely to get a spot on adjustment for as long a range as the 55-300. Knowing the measurements may help to adjust on the fly - I do with my 16-50 ...

totsmuyco · 12-02-2017, 05:49 PM

Thanks everyone but, where can I find this guide? Pardon my ignorance.

kh1234567890 · 12-02-2017, 06:08 PM

Originally posted by BarryE

My pennies worth: Measure the adjustment throughout the range. You might find one end differs a lot more than the rest- this may influence what you choose. Then consider where you want the most accuracy to be, either by most frequently used FL use or where you want the accuracy to be. Measurements and preferences will get you close(ish). Add in field curvature and variations between near and far focus and you're unlikely to get a spot on adjustment for as long a range as the 55-300. Knowing the measurements may help to adjust on the fly - I do with my 16-50 ...

Once set up at infinity and 300mm my DA55-300 seems to be spot on throughout the zoom range ...

35mmfilmfan · 12-03-2017, 01:54 PM

This may be what you are seeking :

Fixing Front and Back Focus - LensAlign MkII - In-Depth Articles

totsmuyco · 12-03-2017, 03:52 PM

Originally posted by 35mmfilmfan

This may be what you are seeking :

Fixing Front and Back Focus - LensAlign MkII - In-Depth Articles

Thank you. Ill check it out

12-02-2017, 04:45 AM	#1
totsmuyco Pentaxian Join Date: Aug 2013 Location: Iloilo City Photos: Gallery Posts: 2,276	Zoom Lens Calibration Is there a guide on how to calibrate zoom lenses? I think my HD 55-300 might need some calibration. Thanks.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Upgrade to FW 1.30 and lens re-calibration	Ofer Hadas	Pentax K-3 & K-3 II	3	02-03-2017 06:20 AM
Lens focus calibration function suggestion/wish!	victormeldrew	Pentax DSLR Discussion	9	09-12-2016 09:31 PM
1 premium WR zoom VS. cheap WR zoom-premium zoom combo	mythguy9	Pentax SLR Lens Discussion	19	11-27-2013 08:51 AM
Lens Focus Calibration - Lens Align vs SpyderdeLensCal vs Focus Pyramid vs Free Stuff	reivax	Pentax SLR Lens Discussion	13	09-06-2013 01:29 AM
Zoom, Zoom, Zoom	racinsince55	Pentax SLR Lens Discussion	11	03-31-2008 07:10 PM

12-02-2017, 07:23 AM	#2
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,472	Originally posted by totsmuyco Is there a guide on how to calibrate zoom lenses? I think my HD 55-300 might need some calibration. Thanks. You do the same process as for a prime. But you have to pick a focal length, and love with any inaccuracy driven by that.

12-02-2017, 07:29 AM	#3
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,342	When I did mine, I checked both ends of the zoom range, and if they differed, I did the adjustment to be nearer the telephoto end, to take account of DOF.

12-02-2017, 11:53 AM	#4
BarryE Site Supporter Join Date: Jan 2013 Location: Hampshire, UK Posts: 1,654	My pennies worth: Measure the adjustment throughout the range. You might find one end differs a lot more than the rest- this may influence what you choose. Then consider where you want the most accuracy to be, either by most frequently used FL use or where you want the accuracy to be. Measurements and preferences will get you close(ish). Add in field curvature and variations between near and far focus and you're unlikely to get a spot on adjustment for as long a range as the 55-300. Knowing the measurements may help to adjust on the fly - I do with my 16-50 ...

12-02-2017, 05:49 PM	#5
totsmuyco Pentaxian Join Date: Aug 2013 Location: Iloilo City Photos: Gallery Posts: 2,276 Original Poster	Thanks everyone but, where can I find this guide? Pardon my ignorance.

12-02-2017, 06:08 PM	#6
kh1234567890 Veteran Member Join Date: Sep 2010 Location: Manchester, UK Photos: Gallery Posts: 2,653	Originally posted by BarryE My pennies worth: Measure the adjustment throughout the range. You might find one end differs a lot more than the rest- this may influence what you choose. Then consider where you want the most accuracy to be, either by most frequently used FL use or where you want the accuracy to be. Measurements and preferences will get you close(ish). Add in field curvature and variations between near and far focus and you're unlikely to get a spot on adjustment for as long a range as the 55-300. Knowing the measurements may help to adjust on the fly - I do with my 16-50 ... Once set up at infinity and 300mm my DA55-300 seems to be spot on throughout the zoom range ...

12-03-2017, 01:54 PM	#7
35mmfilmfan Pentaxian Join Date: Oct 2016 Location: Norfolk, UK Posts: 4,342	This may be what you are seeking : Fixing Front and Back Focus - LensAlign MkII - In-Depth Articles

12-03-2017, 03:52 PM	#8
totsmuyco Pentaxian Join Date: Aug 2013 Location: Iloilo City Photos: Gallery Posts: 2,276 Original Poster	Originally posted by 35mmfilmfan This may be what you are seeking : Fixing Front and Back Focus - LensAlign MkII - In-Depth Articles Thank you. Ill check it out

Zoom Lens Calibration

Win a Pentax Limited Lens: Raffle Now Live!