Help me to improve sharpness at distance

[astalemind]

Hi All,

As a relative newbee to photography I have been having a bit of fun learning about creating images. I am doing it for fun and to be a little bit more creative rather than sit and watch TV every evening.

I have been taking landscapes and urban cityscapes mostly, but recently I have been learning more about portraits.

In my recent attempts with friends and family I have been coming across a issue with the sharpness of my images. I have a couple of lens, Nikon 85mm f1.8 and 50mm f1.8.

I can create nice sharp images when framing in close to a subject, i.e. just on the face, but when I pull back to either frame the subject to the whole of the viewfinder, or say to the left, but with detail, i.e. a wall to the right, I lose loads of sharpness at the point of focus of the image and their faces come out, out of focus.

To experiment, what I have been doing is placing the AF point on the face of the subject's face (not focus and recomposing). On the D90 I have AF points on the 11 point system, so I should be able to focus of any of these points. The problem is, when I look back at the images on the computer the faces are not sharp. Even with a narrow aperture say f8-11-16, the faces still come out less sharp.

I am really puzzled why this might be happening. I am using a shutter speed of 1/200 as I have using flash. To be honest, i've not tried it with a higher shutter speed with natural light yet, but on a a 50mm (crop 75mm) 1/200 should be fast enough.

I am puzzled a little and trying to workout what else I am doing is causing this as I am sure the lenses and the camera have the capability of giving a sharp focus even at a distance, it is user incompetence. I understand that standing back from the subject and taking a full length portrait, isn't going to allow a focus point on the eye, but focusing on the head should be enough to ensure the head and face are in focus, but I can't seem to get this sharp. Or am I expect to much and there will be a level of 'lack of say 100%-80% sharpness' when shooting at a distance.

Can you help with some pointers as to what I could be doing to mess up the sharpness.

Matt

 

[wegotitugetit]

sounds like you auto focus has traking on ie AI servo is on


to take a portrait correctly you should with all portraits AF on the eye then while having your finger pressed half way down reframe the shot and take the picture

how ever if AI servo is on it will keep traking the shot so focus point will move untill you take a shot which will end up in a diffrent position

Ai servo is used when taking sports photos as the subjects move all the time so will need continuos tracking

what you need to do is go into the camera settings and set it to one shot and do as said above with eye and this will in theory correct you problem

also the 11 point AF points are not needed in portrait photography all you do is set the af point to the middle version as this also maybe causing it to been a unsharp image

i hope you can undertsand this only had a hours sleep

 

[astalemind]

sounds like you auto focus has traking on ie AI servo is on


to take a portrait correctly you should with all portraits AF on the eye then while having your finger pressed half way down reframe the shot and take the picture

how ever if AI servo is on it will keep traking the shot so focus point will move untill you take a shot which will end up in a diffrent position

Ai servo is used when taking sports photos as the subjects move all the time so will need continuos tracking

what you need to do is go into the camera settings and set it to one shot and do as said above with eye and this will in theory correct you problem

i hope you can undertsand this only had a hours sleep

Hiya,

Thanks for your comments. Unfortunately I have already have the autofocus and servo is set to single shot rather than continuous focusing, and I depress the shutter to lock focus before I shoot.

In terms of focus on the eye, I do that the best I can, but when I have the camera in portrait orientation, I frame the subject so that the head is on the top focus point and the feet are within the frame also to get a full body shot, the subject is at a distance that the AF point covers the entire face not just the eyes.

Matt

 

[Tokkelossi]

Why cant you use manual focus?

F8 should be fine. Do you shoot 'raw'?

What is your work flow?

Can you post examples

 

[astalemind]

Why cant you use manual focus?

F8 should be fine. Do you shoot 'raw'?

What is your work flow?

Can you post examples

I've never tried manual focus before.

F8, yeap I thought that should work fine. Yes I shoot raw.

I'll post some examples as shortly. I am checking through my images and it seems to be an inconsistent problem for me. Definitely a very 'user' error rather than a lens issues etc. I am trying to workout what I am doing or not doing so I can maintain a consistent quality

Matt

 

[HoppyUK]

It sounds like you are doing eveything right Need to post an example.

The danger areas for sharpness are:

Focus-recompose technique when shooting close at low f/numbers, but you seem to have that sorted.

Slow shutter speed inducing camera shake, but you should be okay at 1/200sec. It's a bit marginal though with an 85mm lens, if you are not the steadiest or have poor technique or just get unlucky with the odd shot. Subject movement is another one of course, but assuming a static subject here.

Finally, diffraction at higher f/numbers. If you are being critical, then fine detail sharpness will begin to fall off around f/11 on a crop format camera. It will be immediately noticeable at f/16 and really quite bad at f/22.

You're not cropping hard or using crazy high ISO?

If you double check all those apsects and make sure they're covered, your images must be sharp.

 

[Tokkelossi]

It sounds like you are doing eveything right Need to post an example.

The danger areas for sharpness are:

Focus-recompose technique when shooting close at low f/numbers, but you seem to have that sorted.

Slow shutter speed inducing camera shake, but you should be okay at 1/200sec. It's a bit marginal though with an 85mm lens, if you are not the steadiest or have poor technique or just get unlucky with the odd shot. Subject movement is another one of course, but assuming a static subject here.

Finally, diffraction at higher f/numbers. If you are being critical, then fine detail sharpness will begin to fall off around f/11 on a crop format camera. It will be immediately noticeable at f/16 and really quite bad at f/22.

You're not cropping hard or using crazy high ISO?

If you double check all those apsects and make sure they're covered, your images must be sharp.

He could be drunk while taking the shots