Can't focus when shooting portrait orientation vs landscape?

[lay-z]

Hi All,

I did a studio photoshoot today and noticed that I was experiencing trouble with getting the focus right when shooting on a "portrait" orientation compared to landscape.

Although I focused exactly on the model's eyes, the focus point always appears elsewhere, such as the garment and even in some cases, the model's feet!

I was using the vertical grip's shutter release when sooting the portrait orientation if that's any useful information but have never experienced this problem when shooting other portraits in the past!

Camera Settings:

Nikon D80
Sigma 30mm f/1.4 @ f/4
1/80 sec (or was it 1/100th?) shutter
centred metering
spot focus selected


I've posted two unedited, uncropped photos as reference. The landscape format is great and in focus as I wanted. However, the portrait seems out of focus on her eyes, which is where I aimed the focus point to be.





Could someone please provide some insight as a few shots are completely unusable due to this problem!

Cheers,

Alan.

[Brian500au]

I am not a Nikon user so please forgive me if I answer by what i know when using a canon. With canon you can select auto focus or you can move the focus point to where you want it to be. Is this the same in the Nikon? Auto focus normally zero's in on the closet part of the image - ie if the dress is closer than the eyes then the dress will be the focus point. This is why you need to use manual focus points when doing this style of work (especially if you are using shallow DOF).

I notice you say you focussed on the eyes but the focus point was elsewhere? Was this whilst looking through the view finder or did you notice in PP?

[jim]

Only thing I can think of is that the peripheral AF sensors on the D80 might be having trouble finding enough contrast when the camera is turned on its side. Though looking at your image its hard to see why that would be an issue.
Can you get good focus using the central sensor?

[Wobbles]

Can you please re-post the pics with exif intact, that may help as well.

[I @ M]

Can we have some more details please?

Are you using AF C or AF S
Are you using the shutter to achieve focus or the ae lock button?
Are you using a single focus point that you determine or are you using a dynamic focus area where the camera determines focus points?
Are you framing, locking focus and then recomposing?

[arthurking83]

If you shot in NEF format then use ViewNX to convert the raw file into a jpg and upload it.
Alternatively, if you shot in jpg mode and need to resize it to upload, then use a program like FSViewer(or similar) that doesn't completely remove the exif data from the images.

The only reason I've used those two examples, is because as far as I'm aware they seem to be the only two programs that don't completely remove all the vital camera related settings from the exif data.
Even tho in most instances that exif data is useless and bloats the size of the file, it's still a good habit to develop where you keep the exif data fully intact for when you do need to refer back to it.

[lay-z]

Hi Brian,

I noticed this both in the viewfinder and in PP when shooting in portrait length.


Jim, that's what I also may suspect.


I@M,

Further details are:

AF-S
Shutter was used to focus
Single point was used to focus
I was framing, locking then recomposing.

Arthur,
Thanks for tip, I used lightroom 2 and it holds the exif data - always keep it as it's a handy point of reference but imgur seems to strip it when I upload through them.

Attached are the photos with exif data. Thanks!



Uploaded with ImageShack.us



Uploaded with ImageShack.us

[ricktas]

YOU are letting the camera choose the AF point. Read your manual and learn how to make the camera work for you, by letting YOU choose the AF point. Simple solution!

[lay-z]

Rick, in reference to the manual and my post above, I've done everything I should (to the best of my knowledge) to let me choose the AF point so I'm not quite sure what else I could have done in this instance other than manually focus?
But like I said, this is only occuring in portrait orientation as opposed to landscape, which focuses without a hiccup.

[arthurking83]

.....
I was framing, locking then recomposing.

Arthur,
Thanks for tip, I used lightroom 2 and it holds the exif data - always keep it as it's a handy point of reference but imgur seems to strip it when I upload through them.

Attached are the photos with exif data. Thanks!

......

Rick, in reference to the manual and my post above, I've done everything I should (to the best of my knowledge) to let me choose the AF point so I'm not quite sure what else I could have done in this instance other than manually focus?
But like I said, this is only occuring in portrait orientation as opposed to landscape, which focuses without a hiccup.

First things first.
While LR does keep some exif, it strips the vital data we need to view to see how your camera is actually set up.

Only way to do this that I know of, is to convert any NEF file with ViewNX(free) or resize any in camera jpg with FSViewer(I think IrfanView may also work).

In the exif data is a host of camera related info, such as how it's set up for focus and so on.

Secondly. If you camera is set up for single point focus it shouldn't be using any other focus point other than the one you've chosen!

Because you are using AF-S mode for focusing, there is no need to lock focus. All you need do is to focus once, once you hear the confirm beep, keeping slight pressure on the release button, recompose and then shoot.

Also! don't assume that because you have locked focus, that you have maintained focus either!

Unless you've set the camera on a tripod, and using focus and recompose, there is almost certainly a very high probability that you're technique is to blame. Also, (which lens?) the lens you are using is almost certain to have an amount of field curvature. That is focusing using the central portion of the len's optical path may not be the same plane of focus as it is at the edges.
I have no idea on how good or bad the Sigma 30/1.4 is with respect to curvature of field.

Also, as I think I'm understanding it: even tho you are in AF-S focus mode and you have set the camera up to only use a single focus point, the camera still automatically chooses it's own (random) focus point?

If this is correct, then I think you haven't properly set the camera up, even tho it seems to work well in landscape orientation, the camera still has the ability(or capability too) focus consistently in the same spot with auto focusing selection.

[lay-z]

First things first.
While LR does keep some exif, it strips the vital data we need to view to see how your camera is actually set up.

Only way to do this that I know of, is to convert any NEF file with ViewNX(free) or resize any in camera jpg with FSViewer(I think IrfanView may also work).

In the exif data is a host of camera related info, such as how it's set up for focus and so on.

Secondly. If you camera is set up for single point focus it shouldn't be using any other focus point other than the one you've chosen!

Because you are using AF-S mode for focusing, there is no need to lock focus. All you need do is to focus once, once you hear the confirm beep, keeping slight pressure on the release button, recompose and then shoot.

Also! don't assume that because you have locked focus, that you have maintained focus either!

Unless you've set the camera on a tripod, and using focus and recompose, there is almost certainly a very high probability that you're technique is to blame. Also, (which lens?) the lens you are using is almost certain to have an amount of field curvature. That is focusing using the central portion of the len's optical path may not be the same plane of focus as it is at the edges.
I have no idea on how good or bad the Sigma 30/1.4 is with respect to curvature of field.

Also, as I think I'm understanding it: even tho you are in AF-S focus mode and you have set the camera up to only use a single focus point, the camera still automatically chooses it's own (random) focus point?

If this is correct, then I think you haven't properly set the camera up, even tho it seems to work well in landscape orientation, the camera still has the ability(or capability too) focus consistently in the same spot with auto focusing selection.

Thanks for the advice Arthur. I've downloaded ViewNX and reised the NEF files to resized JPG keeping all the exif data. It's posted below (third time lucky!) for your reference.

I agree with the second point which is why I'm rather bamboozled with this matter.

You are right with the AF-S mode and that's exactly how I composed my shots.

I'm happy to admit that it could be my technique at the end of the day and hence would like to know what I can do to prevent this from re-ocurring.

That's my presumption at this point in time is that the camera appears to be selecting its own focus point despite where I am telling it to focus, as such, it could may well be the camera isn't setup correctly but then with that mentioned, how should it be setup to prevent and correct this issue?

Edit: I just had a look myself and noticed these shots were on AF-A and Dynamic AF area, however, I switched these settings to AF-S and Single AF area in subsequent shots and still experienced the same problem

Images with full exif data from ViewNX:



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If these don't work I'm happy to email you and do appreciate your assistance so far as it's making all the gears tick up in the noggin!

Cheers.

[lay-z]

I just had a look myself and noticed these shots were on AF-A and Dynamic AF area, however, I switched these settings to AF-S and Single AF area in subsequent shots and still experienced the same problem.

here's another example with the above mentioned settings (You'll notice the focus point selected was on the subject's face, but her right shoulder is in focus instead):



Uploaded with ImageShack.us

[arthurking83]

..... I switched these settings to AF-S and Single AF area in subsequent shots and still experienced the same problem.

here's another example with the above mentioned settings (You'll notice the focus point selected was on the subject's face, but her right shoulder is in focus instead):
.....

Well we now have the exif info we required, which confirms that the AF mode was both dynamic and AF-A mode, so as to why it's still dynamically choosing the AF point could be due to not setting the AF-S/Single AF mode with the OK button as confirmation
Otherwise!
As you said, AF point selection may have been on the model's face but focus definitely seems to be further behind going by the perceived sharpness in the image.
AF point selection isn't confirmed in the exif data in this image, but that's not unusual(whereas it is confirmed in the landscape orientated image above), but this may not be the problem.
In using focus and recompose in this manner, you are open to a few variables that could easily lead to focus errors.
1. As you recompose, you must be slightly (in this case)leaning forward during the movement of your upper body which is obviously going to place the plane of focus outside of the area you want it to be in.
(suggested fix could be that when you recompose do so with a slight lean backwards as a change in your technique .. and see and see if something like that helps)
2. the model may be moving fore-aft in the split second between focus and recompose.
Remember that you are both dynamic targets relative to each other and error in focusing in this manner will be very common.
3. lens may be backfocusing.
If you add up all those possible causes for misfocusing you could easily end up tearing out all your hair in trying to find a solution... never mind the strange behaviour of the camera in choosing an AF point dynamically where it should be set and fixed!

So(if the camera is set to single point focus) do you see the af point illuminate in the viewfinder?
You have your function button set to AF Area mode selection. Are you inadvertently pressing this and altering the af area mode?(I know it's a long shot, but worth a try). BTW! What's is set to?
from the exif it does say that the first two images above are set to dynamic and that the last on is set to single area, so in the last image you've presented, looking through the viewfinder, the af point you've chosen should light up red(as you focus) and stay put, whereas in the other images(set to dynamic area) the af point should either not be visible, or it should move about in the viewfinder until it finds the closes subject matter to focus on.

[lay-z]

In using focus and recompose in this manner, you are open to a few variables that could easily lead to focus errors.
1. As you recompose, you must be slightly (in this case)leaning forward during the movement of your upper body which is obviously going to place the plane of focus outside of the area you want it to be in.
(suggested fix could be that when you recompose do so with a slight lean backwards as a change in your technique .. and see and see if something like that helps)
2. the model may be moving fore-aft in the split second between focus and recompose.
Remember that you are both dynamic targets relative to each other and error in focusing in this manner will be very common.
3. lens may be backfocusing.
If you add up all those possible causes for misfocusing you could easily end up tearing out all your hair in trying to find a solution... never mind the strange behaviour of the camera in choosing an AF point dynamically where it should be set and fixed!.

Cheers for these possible solutions Arthur and I'll definitely be mindful of these variables next time I do such a shoot as it did become frustrating throughout the shoot!

So(if the camera is set to single point focus) do you see the af point illuminate in the viewfinder?
You have your function button set to AF Area mode selection. Are you inadvertently pressing this and altering the af area mode?(I know it's a long shot, but worth a try). BTW! What's is set to?
from the exif it does say that the first two images above are set to dynamic and that the last on is set to single area, so in the last image you've presented, looking through the viewfinder, the af point you've chosen should light up red(as you focus) and stay put, whereas in the other images(set to dynamic area) the af point should either not be visible, or it should move about in the viewfinder until it finds the closes subject matter to focus on

Re AF-S - yes, the AF point is always illuminated red before taking the exposure.
And I can confirm that I do not accidentally push the function button as I'm composing for a shot as my fingers are clear from that area of the function button.

You are right with the first few shots being taken on dynamic AF mode (with the ability for me to choose the focus point). I then changed the AF mode to AF-S after noticing the off focus as seen in the third image posted.

So far it appears the problem could be any of the 3 points you raised above and I did not make notice that both myself and the subject were moving whilst recomposing/achieving focus lock and that may as well be the cause.

I really hate to resort to "back focus" or "front focus" as 'excuses' until all other possibilities are ruled out as I always think it's a "cheap" way out of answering the problem.

Thanks again for the abundance of information and it's sincerely appreciated!