[Tonytee]

Let's see. On my most recent shoot (4-15-2023) I noticed images with focus issues. Areas where the focal plane did not come into contact with, were sharper than areas

that did come into contact with the Focal Plane. The center was alright, but not as sharp as the other areas that were afar from center. Will be happy to provide the one

image that I am referring to. Yes, the Auto-Focus Indicator was dead on the subject, shake reduction was not on because I used my tripod.


Thanks very much.

Tonytee.

[StiffLegged]

Might be time to revisit the Dot Tune focus calibration, but is this true for all lenses or just one? And are you focusing through the viewfinder or using live view focus?

[UncleVanya]

Yes, the Auto-Focus Indicator was dead on the subject, shake reduction was not on because I used my tripod.

Which lens?
Yes, please post the file.
When you say the focus indicator, I assume you mean the red dot? That only indicates where focus is being attempted. Was the green hexagon fully lighted and solid - not blinking?

[Tonytee]

Might be time to revisit the Dot Tune focus calibration, but is this true for all lenses or just one? And are you focusing through the viewfinder or using live view focus?

This is the first time I have noticed the issue with this lens. On occasion there have been issues with the SMC Takumar F 70~210mm lens, although this lens is known for

inconsistent Auto-Focus. Nothing wrong with it, just the way it is made. I will go ahead and upload the image I am referring to. I will include EXIF Data.

Thnx,

Tony

---------- Post added 04-22-23 at 10:18 AM ----------

Which lens?
Yes, please post the file.
When you say the focus indicator, I assume you mean the red dot? That only indicates where focus is being attempted. Was the green hexagon fully lighted and solid - not blinking?

In this instance, I am referring to the SMC Pentax-FA 28 ~ 80mm lens. It appears as though I misspoke regarding which light. I meant to refer to the In-Focus Hexagon,

Yellow Light which was in the solid position when shooting. I will go ahead and upload the image in a minute.

Thanks,

Tony

---------- Post added 04-22-23 at 10:19 AM ----------

Here is the image. As is readily visible, the in focus areas are all over the map. Everywhere except where I needed it.

Thanks very much.

Tony

Attached Images

View Picture EXIF

File Date

 

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Last edited by Tonytee; 04-22-2023 at 10:21 AM.

[C_Jones]

I would try using a higher F stop number like 9 or 10 and see if it possibly affects the image features. If so, it may be just the need to have a greater depth of field than in the previous image you revealed. Also, I would make sure to not be too close to the subject for the camera, being that too close may not allow it to focus normally.

[Tonytee]

I would try using a higher F stop number like 9 or 10 and see if it possibly affects the image features. If so, it may be just the need to have a greater depth of field than in the previous image you revealed. Also, I would make sure to not be too close to the subject for the camera, being that too close may not allow it to focus normally.

Thank you very much. I will certainly try that. I have been working indoors with the k-7 and the SMC Takumar F 70~210mm 1: 4 ~ 5.6 lens and surprisingly, it is very sharp

@ 135mm. So sharp, it did not require any sharpening in post. However, when I brought the lens in all the way to 210mm, the in focus indicator was solid, but when I went

ahead and uploaded the image, it was way out of focus. This is causing me to be suspect that there is an underlying problem somewhere. I do not have another body to test

the lens on.

Thanks again,

Tony

[OrchidJulie]

Hi, Tony...

Looks like a DOF issue to me, too... note that the leaves in the lower right are in good focus, but the flower parts that are closer to the camera aren't. The suggestion to try a higher F-stop is a good one. If that drops the shutter speed too low for comfortable hand-held, and you don't have a tripod, increase the ISO. Or use aperture-priority and let the camera adjust shutter and ISO. Keep minimum focus distance in mind, too.

[Tonytee]

Hi, Tony...

Looks like a DOF issue to me, too... note that the leaves in the lower right are in good focus, but the flower parts that are closer to the camera aren't. The suggestion to try a higher F-stop is a good one. If that drops the shutter speed too low for comfortable hand-held, and you don't have a tripod, increase the ISO. Or use aperture-priority and let the camera adjust shutter and ISO. Keep minimum focus distance in mind, too.

Thank you very much there, Senorita. Also, I am aware that typically, long telephotos are soft at the long end, but my contention is: Why does the in-focus indicator tell me that everything is in focus when it clearly is not? Seems to be a false positive or some type of software glitch. It is time for a tune up on this oldie but
goodie. Thnx again. TT

Tony

[Just1MoreDave]

Thank you very much there, Senorita. Also, I am aware that typically, long telephotos are soft at the long end, but my contention is: Why does the in-focus indicator tell me that everything is in focus when it clearly is not? Seems to be a false positive or some type of software glitch. It is time for a tune up on this oldie but
goodie. Thnx again. TT

Tony

It's telling you something (at a certain AF point) is in focus. My K-7 is set to only use the center point. For me, that's less confusing. I make sure what I need in focus is under that point, then shoot. Then I only have to worry about whether the lens front or back focuses, wind, depth of field and my movement to get exactly the photo I want.

[pschlute]

Everywhere except where I needed it.

The point is you need to tell the camera where you need it.

What AF mode were you using ? ........ multi/centre 9/ centre only ?

[pschlute]

Why does the in-focus indicator tell me that everything is in focus when it clearly is not?

The in-focus indicator (green hexagon) will only tell you that AF lock has been achieved for the AF points you have told the camera to use. It has never been able to tell you that "everything is in focus", and never will.

[UncleVanya]

The in-focus indicator (green hexagon) will only tell you that AF lock has been achieved for the AF points you have told the camera to use. It has never been able to tell you that "everything is in focus", and never will.

I think you misread the earlier posts. He says that the place he has Focus indicated is not the place where things are in focus. I’m unclear if he has done adequate fine focus adjustment which may account for this difference.

[C_Jones]

For example, first of all, if I am looking for a depth of field that will be mostly effective I may try F 11. if I am too close to something with my Sigma 150-500 and Pentax K-5 IIs, I cannot achieve detail on the subject, but if I move away another 15 feet, it may come into focus because I am not too close. That is just a simple example. With a telephoto lens I try to use F10 or higher of a number F stop just to make sure the depth I am using is going to have a good affect on the image detail. That is why I like to shoot on mostly sunny days, so that I can use an F stop that will give me detail without too high of an ISO.

[pschlute]

I think you misread the earlier posts. He says that the place he has Focus indicated is not the place where things are in focus.

He is talking about the hexagon

[Tonytee]

Okay, after reading again all of the fine helpful hints and suggestions, I decided to go ahead and conduct an experiment to reveal to everyone how this set up works for me. I used the same body,

(only Pentax body I have) along with an SMC Takumar F 70~210mm 1:4 ~ 5.6 Lens. I have taken four exposures, all every one with the exact same settings, same subject at different exposure

lengths with absolutely no Post adjustments. I will also provide EXIF data for each image. I want to ask for patience here as I would like to add my own narrative on each image prior to uploading.

Thanks again, Tony