[traxino]

Hi All,

In January I bought the K1 and we are on good way to became best friends. Unfortunately I had no chance to use it too much, but I found a very annoying issue. When I'm shooting landscapes, it happens very often that I cannot take the picture because the focus indicator is blinking. I recorded a video. Is this a lens/body/settings issue? The DFA 28-135 was on the body, I'm unsure whether the same happens with other lenses or not.

I'm not new to Pentax, I bought my first camera in 2012 and I've never had this problem on the K30 with any of the lenses (I've never tried the 28-135 on the K30).

Did any of you have similar experience?

Thanks,
Steve

[BigMackCam]

This may seem like a silly question, Steve, but have you checked that you're set to auto-focus rather than manual-focus?

[traxino]

This may seem like a silly question, Steve, but have you checked that you're set to auto-focus rather than manual-focus?

Fair question. I checked it and AF was selected.

[RedRuff]

When I got my K1 I turned off focus priority. It's a useful feature I guess but I didn't want to get myself into a situation where I want to take a photo but the camera won't let me because it hasn't nailed focus.

I'm not sure if that's your issue or not but it looks like your focus indicator is flashing

[BigMackCam]

Fair question. I checked it and AF was selected.

Hmm. Does the focusing mechanism of the lens operate? If you set it to, say, minimum focusing distance manually, then use AF to focus on a distant subject, does the lens' focus change or does it stay at minimum?

[AfterPentax Mark II]

If I look at the scene in the viewfinder I see a flashing hexagon and when that happens to me it is usually that there is not enough contrast in the scene. Strong backlight and a huge green field. My K-3 II won't let me take a picture then. Even turning to the trees does not help. I think it is not the camera or the lens, but the scene you have chosen. Flashing hexagon means that the camera cannot lock focus. It happens me in a lot of situations, usually because I did not take attention to the kind of scene I want to picture, because my eyes were focused to one particular part. In manuals of older camera's they usually explain why and when the hexagon flashes. It seems that this explanation is not part of the K-1 MkII manual. Hope this helps.

[traxino]

When I got my K1 I turned off focus priority. It's a useful feature I guess but I didn't want to get myself into a situation where I want to take a photo but the camera won't let me because it hasn't nailed focus.

I'm not sure if that's your issue or not but it looks like your focus indicator is flashing

Yeah, I turned that off but nothing has changed.

---------- Post added 09-01-21 at 07:40 PM ----------

When I got my K1 I turned off focus priority. It's a useful feature I guess but I didn't want to get myself into a situation where I want to take a photo but the camera won't let me because it hasn't nailed focus.

I'm not sure if that's your issue or not but it looks like your focus indicator is flashing

Yes it does. So, it happens only when I'm shooting something very far, if the lens is not on 28mm but closer like 40mm and I'm shooting the same there is no issue at all.

---------- Post added 09-01-21 at 07:41 PM ----------

If I look at the scene in the viewfinder I see a flashing hexagon and when that happens to me it is usually that there is not enough contrast in the scene. Strong backlight and a huge green field. My K-3 II won't let me take a picture then. Even turning to the trees does not help. I think it is not the camera or the lens, but the scene you have chosen. Flashing hexagon means that the camera cannot lock focus. It happens me in a lot of situations, usually because I did not take attention to the kind of scene I want to picture, because my eyes were focused to one particular part. In manuals of older camera's they usually explain why and when the hexagon flashes. It seems that this explanation is not part of the K-1 MkII manual. Hope this helps.

Yep, this is what I felt it behaved like there is not enough contrast.

[MarkJerling]

Hi All,

In January I bought the K1 and we are on good way to became best friends. Unfortunately I had no chance to use it too much, but I found a very annoying issue. When I'm shooting landscapes, it happens very often that I cannot take the picture because the focus indicator is blinking. I recorded a video. Is this a lens/body/settings issue? The DFA 28-135 was on the body, I'm unsure whether the same happens with other lenses or not.

I'm not new to Pentax, I bought my first camera in 2012 and I've never had this problem on the K30 with any of the lenses (I've never tried the 28-135 on the K30).

Did any of you have similar experience?

Thanks,
Steve

I'd suggest that you test with your other lenses.

[UncleVanya]

Was this problem only happening when shooting via the viewfinder or is it also happening in live view? Sometimes I have switched from viewfinder PDAF to the LCD CDAF to get past focusing difficulties on my K3 or KP. Both systems struggle when light levels are lower, but typically one or the other can acquire focus well.

I agree with the suggestion to test another lens also. I had a customer with a DA* 50-135 that struggled to focus in sdm in lower light and low contrast situations but otherwise seemed to focus accurately. It too would fail to indicate focus lock. Oddly converting that lens to screw drive changed the behavior, eliminating the failure to focus. This puzzled me until I read this article on PDAF and CDAF in smartphones: Phase Detection vs Contrast Detection Autofocus

Essentially, PDAF requires the lens to make precise movements predicted by the camera’s prediction of focus. The failing SDM send to have lacked precision compared to the expected outcome. Screwdrive Precision has always seemed lower with more jittery adjustments in focusing (even in PDAF) so my assumption is that this allowed his lens to focus by not giving up as quickly. Ultimately it’s unclear if the sdm motor or the optics or the electronics in the lens caused the issue, but it was clearly a lens problem since it happened across multiple bodies and switching lenses resolved the problem. All of this is a long winded explanation as to how small glitches in the lens could impact focusing accuracy in specific situations where the contrast is reduced or light levels are lower.

[mikesbike]

The DFA 28-135

Do you mean the DFA 28-105mm that is offered with the K-1 II as a kit? I have that same setup and have had no AF issues so far. All I can think of is when shooting landscapes it is still necessary to pick out a focus subject for the AF to grab onto.

[stevebrot]

Looking back on your history, you have had both camera and lens for awhile. I also noticed that the camera was purchased new with the D FA 24-70/2.8. I also found a post with very nice sunset photo taken with the 28-105 where focus was not an issue. Post your K-1 pictures! - Page 2087 - PentaxForums.com

I would test (on tripod*) against an unambiguous subject at distance (as with the sunset above) with both the 28-105 and a different lens. I would then attempt with a few ambiguous subjects (as with the video you shared). If the camera fails, I suggest attempting manual focus in magnified live view to see it is working with.


Steve

* Yes, tripod. If the subject is ambiguous and the view over the AF sensor is shifting, difficulty differentiating OOF is sort of a given.

[traxino]

Was this problem only happening when shooting via the viewfinder or is it also happening in live view? Sometimes I have switched from viewfinder PDAF to the LCD CDAF to get past focusing difficulties on my K3 or KP. Both systems struggle when light levels are lower, but typically one or the other can acquire focus well.

I agree with the suggestion to test another lens also. I had a customer with a DA* 50-135 that struggled to focus in sdm in lower light and low contrast situations but otherwise seemed to focus accurately. It too would fail to indicate focus lock. Oddly converting that lens to screw drive changed the behavior, eliminating the failure to focus. This puzzled me until I read this article on PDAF and CDAF in smartphones: Phase Detection vs Contrast Detection Autofocus

Essentially, PDAF requires the lens to make precise movements predicted by the camera’s prediction of focus. The failing SDM send to have lacked precision compared to the expected outcome. Screwdrive Precision has always seemed lower with more jittery adjustments in focusing (even in PDAF) so my assumption is that this allowed his lens to focus by not giving up as quickly. Ultimately it’s unclear if the sdm motor or the optics or the electronics in the lens caused the issue, but it was clearly a lens problem since it happened across multiple bodies and switching lenses resolved the problem. All of this is a long winded explanation as to how small glitches in the lens could impact focusing accuracy in specific situations where the contrast is reduced or light levels are lower.

AH-HA! I think this is it. I didn't have any problem using the live view. Thanks for the links, it was very interesting read to me.

---------- Post added 09-07-21 at 05:41 PM ----------

Looking back on your history, you have had both camera and lens for awhile. I also noticed that the camera was purchased new with the D FA 24-70/2.8. I also found a post with very nice sunset photo taken with the 28-105 where focus was not an issue. Post your K-1 pictures! - Page 2087 - PentaxForums.com

I would test (on tripod*) against an unambiguous subject at distance (as with the sunset above) with both the 28-105 and a different lens. I would then attempt with a few ambiguous subjects (as with the video you shared). If the camera fails, I suggest attempting manual focus in magnified live view to see it is working with.


Steve

* Yes, tripod. If the subject is ambiguous and the view over the AF sensor is shifting, difficulty differentiating OOF is sort of a given.

Yeah, I had this experience only when the lens was wide open, the sunset picture was taken at 105mm. Testing on the tripod sounds an interesting idea to me, it didn't come to my head. Thanks for the input!

---------- Post added 09-07-21 at 05:47 PM ----------

Do you mean the DFA 28-105mm that is offered with the K-1 II as a kit? I have that same setup and have had no AF issues so far. All I can think of is when shooting landscapes it is still necessary to pick out a focus subject for the AF to grab onto.

I've bought it as used from the forum, it didn't arrive in a kit. As you said (and from the other replies I concluded the same): "it is still necessary to pick out a focus subject for the AF to grab onto". I'm just wondering how I didn't face with this problem with the K30

[mikesbike]

I'm just wondering how I didn't face with this problem with the K30

Every shot is different. Sometimes this is less of an issue.