Frontfocus problem and focus assist lamp

GabrielFFontes · 06-07-2012, 06:32 PM

Hi guys!
I know many of you have been complaining about FF problems, and i've been thinking of a very simple (and very stupid) "fix"
If you put your hand on the front of the lens, and then take it off, the focus assist lamp will be used for the focusing...maybe this will solve the front focus problem? (if Pentax won't fix, then lets try ourselves)

Adam · 06-07-2012, 06:37 PM

The lamp just illuminates things- it shouldn't have any effect on FF. FF is fixable, though:

Fixing Front and Back Focus - Introduction - PentaxForums.com

**JimJohnson** · 06-07-2012, 06:52 PM - **1 Like**

Take 10 minutes to read this:
PENTAX DSLRs: Front or Back Focusing Problems? Free test (Lens Alignment) charts for Pentax, Nikon, Canon, Sony, Olympus.
Then take maybe another 30 minutes and do it.

Adam's solution is also good but is going to set you back a pretty penny for a tool that you will use exactly once. The solution I found is just as effective and the only cost is printing a sheet of paper and trimming it with a pair of scissors. Not to mention that it is something you can do right now and not wait for the expensive tool to be shipped to you.

GabrielFFontes · 06-07-2012, 07:02 PM

Hey guys!
I've adjust my autofocus already, but i use a K-r, so i can't adjust specific lenses, etc (although i just set it to -16 for every lens in tungsten, when needed...i do that my setting it to -6 on debug mode, so i can set it to +6 on my menu to cancel the effect when using it on daylight, and then set it to -10 when in tungsten [so i can get -16])
The frontfocus isn't ALL that annoying to me..but i posted this idea to help other people.
Also, that FF happens under tungsten lightning, so when the autofocus assist light illuminates the room with a green light, shouldnt it kind of help with the TUNGSTEN FF problem?

Also, Adam : thats your 20,000th post!

Philoslothical · 06-07-2012, 09:13 PM

Originally posted by GabrielFFontes

Also, that FF happens under tungsten lightning, so when the autofocus assist light illuminates the room with a green light, shouldnt it kind of help with the TUNGSTEN FF problem?

In theory, it could help, yeah. You'd have to be quite close to subject, as the lamp isn't very bright. But in theory, raising the colour temperature of the scene by adding light should help with the tungsten issue. A small LED flashlight would help just as much, and perhaps end up being more convenient.

GabrielFFontes · 07-06-2012, 07:17 PM

Hey guys!
I did a test, and until 2 meters the af assist light solves the tungsten ff problem completely...
At least for me, as you can see on those crops

Just hope this helps someone

PS : Will conduct a test at something like 5 meters and see if it is as effective as on this test

06-07-2012, 06:32 PM	#1
GabrielFFontes Veteran Member Join Date: Jul 2011 Location: Rio de Janeiro, Brazil Posts: 647	Frontfocus problem and focus assist lamp Hi guys! I know many of you have been complaining about FF problems, and i've been thinking of a very simple (and very stupid) "fix" If you put your hand on the front of the lens, and then take it off, the focus assist lamp will be used for the focusing...maybe this will solve the front focus problem? (if Pentax won't fix, then lets try ourselves)

06-07-2012, 06:37 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,597	The lamp just illuminates things- it shouldn't have any effect on FF. FF is fixable, though: Fixing Front and Back Focus - Introduction - PentaxForums.com 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:

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06-07-2012, 06:52 PM - 1 Like	#3
JimJohnson Loyal Site Supporter Join Date: Jan 2012 Location: Summer:Lake Superior - Michigan Winter:Texas Hill Country Photos: Gallery Posts: 2,774	Take 10 minutes to read this: PENTAX DSLRs: Front or Back Focusing Problems? Free test (Lens Alignment) charts for Pentax, Nikon, Canon, Sony, Olympus. Then take maybe another 30 minutes and do it. Adam's solution is also good but is going to set you back a pretty penny for a tool that you will use exactly once. The solution I found is just as effective and the only cost is printing a sheet of paper and trimming it with a pair of scissors. Not to mention that it is something you can do right now and not wait for the expensive tool to be shipped to you.

06-07-2012, 07:02 PM	#4
GabrielFFontes Veteran Member Join Date: Jul 2011 Location: Rio de Janeiro, Brazil Posts: 647 Original Poster	Hey guys! I've adjust my autofocus already, but i use a K-r, so i can't adjust specific lenses, etc (although i just set it to -16 for every lens in tungsten, when needed...i do that my setting it to -6 on debug mode, so i can set it to +6 on my menu to cancel the effect when using it on daylight, and then set it to -10 when in tungsten [so i can get -16]) The frontfocus isn't ALL that annoying to me..but i posted this idea to help other people. Also, that FF happens under tungsten lightning, so when the autofocus assist light illuminates the room with a green light, shouldnt it kind of help with the TUNGSTEN FF problem? Also, Adam : thats your 20,000th post!

06-07-2012, 09:13 PM	#5
Philoslothical Veteran Member Join Date: May 2011 Posts: 1,889	Originally posted by GabrielFFontes Also, that FF happens under tungsten lightning, so when the autofocus assist light illuminates the room with a green light, shouldnt it kind of help with the TUNGSTEN FF problem? In theory, it could help, yeah. You'd have to be quite close to subject, as the lamp isn't very bright. But in theory, raising the colour temperature of the scene by adding light should help with the tungsten issue. A small LED flashlight would help just as much, and perhaps end up being more convenient.

07-06-2012, 07:17 PM	#6
GabrielFFontes Veteran Member Join Date: Jul 2011 Location: Rio de Janeiro, Brazil Posts: 647 Original Poster	Hey guys! I did a test, and until 2 meters the af assist light solves the tungsten ff problem completely... At least for me, as you can see on those crops Just hope this helps someone PS : Will conduct a test at something like 5 meters and see if it is as effective as on this test