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06-20-2011, 11:52 AM   #1
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K-5 Manual Lens Front Focus & Focus Beep woes fixed

Just got myself a K-5 (today) and the first lens I fitted on to test at the shop was a Super Takumar 50/1.4 . As usual the shots were satisfactory yet I realised there was no focus confirm beep which my K-x used to give me. But I bought it nonetheless due to my sheer faith in pentax.

I also realised when I brought it home that I kept focusing in front of the subject when Im shooting something near especially a min-focal distance. Then it struck me that when I fitted my lens I didnt have the same Focal Length selection my k-x threw me each time I whipped out a lens older than me.

After some searching in the forums, and scouring the manual for answers, I ended up reading a lot on AF Adjustments on AF lenses, tweaking the settings didn't help (yeah because its for AF duh) but after looking closely I stumbled on a helpful forum member who explained that you needed to allow usage of Aperture Ring in the menu for manual lenses.

With that enabled, I was able to input focal length on a restart of the camera. Of which the Focus Beep came back! And to my delight it was the first time I saw the red square in the view finder lighting up (I didnt use any AF lenses yet) and it felt so good

I never knew what this focal length input actually meant and always just put in whatever the len's focal length was. So this time i put in 50mm and started shooting, and realised there was this irritating focus issue where I would have my focus point a tad lower then where my viewfinder focus'ed. And after spending 15mins playing around. I realised the Focal Length Input was supposed to be AFTER multiplying the crop factor.

And after setting to 75mm, my 50/1.4 super take focus'ed spot on And I was being a dipshit fiddling with the AF Adjustment amidst my immense confusion ;x

I hope this helps anyone out there with Manual Lens focusing issues! As I only tested this with my 50mm it may have different results, ill try with my 135 and report

06-20-2011, 12:02 PM   #2
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Hmmmm interesting the focus confirm beep is also off from where it should be when I use MF lenses....Ill have to try this
06-20-2011, 02:00 PM   #3
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QuoteOriginally posted by kneonx Quote
Just got myself a K-5 (today) and the first lens I fitted on to test at the shop was a Super Takumar 50/1.4 . As usual the shots were satisfactory

I never knew what this focal length input actually meant and always just put in whatever the len's focal length was. So this time i put in 50mm and started shooting, and realised there was this irritating focus issue where I would have my focus point a tad lower then where my viewfinder focus'ed. And after spending 15mins playing around. I realised the Focal Length Input was supposed to be AFTER multiplying the crop factor.

And after setting to 75mm, my 50/1.4 super take focus'ed spot on And I was being a dipshit fiddling with the AF Adjustment amidst my immense confusion ;x

I hope this helps anyone out there with Manual Lens focusing issues! As I only tested this with my 50mm it may have different results, ill try with my 135 and report
I'll have to read my manual again, i've always inputted the lens FL. Besides the FL input screen is only for SR purposes, it does not affect focusing, as far as i know.
06-20-2011, 02:59 PM   #4
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QuoteOriginally posted by kneonx Quote
I realised the Focal Length Input was supposed to be AFTER multiplying the crop factor.
That may have luckily worked for you but there is no math involved when selecting the FL for the shake reduction. 50mm is 50mm.

06-20-2011, 03:10 PM   #5
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QuoteOriginally posted by philbaum Quote
I'll have to read my manual again, i've always inputted the lens FL. Besides the FL input screen is only for SR purposes, it does not affect focusing, as far as i know.
I think this is correct
06-20-2011, 06:40 PM   #6
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Maybe it was the use of aperture ring that set the focus proper. No idea, but apparently the only thing I changed was the 2 settings One of them worked haha ... And the focus change wasnt like a millimeter diff, it was quite off.

Another possible theory I could think off is because I restarted the camera, the AF Fine Adjustment kicked in and did some compensation?

I just tried resetting everything and going at it again, having that front focusing again haha ... and yeah Focal length doesnt seem to be doing anything this time round.

I suppose as specialk points out its used for its traditional purpose of calculating how much SR to use.

It's a pain to know your manual focus lens are spot on ... cant imagine taking a perfectly beautiful portrait shot at 1.4 and then looking at the lcd with a blur face
12-14-2011, 08:15 PM   #7
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By inputting 75mm for a 50mm lens, if shake reduction (SR) is on, it will over compensate and give less sharpness than if set at the focal length. As the others have said, FL is FL is FL. No math is involved and the FL of a lens stays the same regardless of camera its placed on. Its the angle of view that changes.....lots of threads explaining this horrible misunderstanding propagated everywhere. Forget the 1.5x.
12-14-2011, 08:31 PM   #8
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If this were true, it would be absurd for Pentax to require the user to make the calculation when dialing in the settings for SR. There's only one crop factor for the camera! If the SR needed a setting of 75 for a FL of 50, then the camera would presumably just treat 50 as if it were 75. Unless the designers were insane.


Last edited by pentup; 12-14-2011 at 08:39 PM.
12-15-2011, 03:16 AM   #9
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There is noa known linkage to focusing indicatn and the focal length input. You are to enter the true focal length not after applying crop factor. That's how it has always been. What ever you have done, I don't know. But it is not correct.

Why not post some photos so we can see
12-15-2011, 04:54 AM   #10
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From what I've read...as is stated previously...the FL input is only for shake reduction.

I shoot a K-r but the effect is the same. I get the red focus confirmation square with MF lenses but I have found it to be very inaccurate. In fact, I get different results if I approach the focus from the infinity side rather than from the close side. With the red focus square illuminated...I can actually turn the focus ring slightly in each direction without the red square turning off.

I generally ignore the focus confirmation square for MF lenses and use my eyes only.

AB
12-15-2011, 05:00 AM   #11
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QuoteOriginally posted by ablundon Quote
I generally ignore the focus confirmation square for MF lenses and use my eyes only.
Like me. That's what eyes are for.
It's too much hassle keeping a lookout for the stupid focus confirmation whateveritis.
12-15-2011, 08:09 AM   #12
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QuoteOriginally posted by rawr Quote
Like me. That's what eyes are for.
It's too much hassle keeping a lookout for the stupid focus confirmation whateveritis.
A properly adjusted diopter and my eyes are my tools for MF. Although I wear glasses now, I will still trust my eyes over ears. One of the issues that often comes up with AF discussions is that a camera can sometimes lock on to something near the intended focus point rather then the actual subject. Since the focus confirmation beep and octogon indicator use that same system, it can sometimes be wrong too. The highly desired quick shift feature on some lenses is there for exactly that reason. If you are going to use MF lenses a lot, a Katz Eye or similar focusing screen would be a good investment.
12-15-2011, 11:23 AM   #13
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This does not make sense to me... the reason to input the focal length of the MF lens is to let the camera know how the SR adjustment should be made... nothing to do with focusing. I strongly suggest that you try another MF lens to see if it is the lens problem. Unfortunately for MF lens, there is no individual lens micro adjustment for FF or BF, just a universal adjustment that applies to all lenses.
12-15-2011, 11:26 AM   #14
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In fact, there is one more step you could try, which is to enable catch-in-focus... so when you hold the shutter button down and keep turning the focus ring, the green focus confirmation light comes up and the shutter is released. That is what I get when I use my M50mm 1.4 lens.

Last edited by aleonx3; 12-15-2011 at 12:33 PM.
04-12-2014, 03:47 PM   #15
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QuoteOriginally posted by kneonx Quote
Just got myself a K-5 (today) and the first lens I fitted on to test at the shop was a Super Takumar 50/1.4 . As usual the shots were satisfactory yet I realised there was no focus confirm beep which my K-x used to give me. But I bought it nonetheless due to my sheer faith in pentax.

I also realised when I brought it home that I kept focusing in front of the subject when Im shooting something near especially a min-focal distance. Then it struck me that when I fitted my lens I didnt have the same Focal Length selection my k-x threw me each time I whipped out a lens older than me.

After some searching in the forums, and scouring the manual for answers, I ended up reading a lot on AF Adjustments on AF lenses, tweaking the settings didn't help (yeah because its for AF duh) but after looking closely I stumbled on a helpful forum member who explained that you needed to allow usage of Aperture Ring in the menu for manual lenses.

With that enabled, I was able to input focal length on a restart of the camera. Of which the Focus Beep came back! And to my delight it was the first time I saw the red square in the view finder lighting up (I didnt use any AF lenses yet) and it felt so good

I never knew what this focal length input actually meant and always just put in whatever the len's focal length was. So this time i put in 50mm and started shooting, and realised there was this irritating focus issue where I would have my focus point a tad lower then where my viewfinder focus'ed. And after spending 15mins playing around. I realised the Focal Length Input was supposed to be AFTER multiplying the crop factor.

And after setting to 75mm, my 50/1.4 super take focus'ed spot on And I was being a dipshit fiddling with the AF Adjustment amidst my immense confusion ;x

I hope this helps anyone out there with Manual Lens focusing issues! As I only tested this with my 50mm it may have different results, ill try with my 135 and report
Thanks. Changing the focal length after multiplying by the crop factor worked like charm. My 50mm 1.4 would not focus properly until I tried this, my other manual focus lenses seemed to focus fine without the adjustment but I am going to re-check all of them.
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