Sharpness problems please help

[kiwi]

As said before if anyone really thinks you have a problem with your gear (ie backfocussing etc) then its very simple to do a controlled test - DO NOT TEST ON A PERSON OR A MOVING OBJECT OF ANY KIND OR HANDHELD

Use a tripod, or put camera on a steady surface, a table etc
Use either a remote release or the timer
Make sure you focus exactly on the object
line up a few objects in front and behind the main focus point (use cans or boxes etc) or a focus test chart (google it)
use flash so that your s/s is at least 1/200s
Shoot JPEG
Shoot at ISO200

etc

Do a controlled test before even thinking about blaming cameras or lenses for OOF shots


Story - about a year ago a friend had bought a brand new d300 with 24-70 lens as she claimed her d80 and 18-200 was too soft. I could still use her old gear and get sharper shots, and her d300 and 24-70 and get nothing sharper. She couldnt get sharp shots with either combo. Its hardly ever the equipment

[swifty]

Just a few tidbits that might help. Try kiwi's controlled test first. Maybe use a 30cm ruler and shoot from an angle on the 15cm mark using centre focus spot. Repeat and see if it consistently focus on the same spot. If so, is the focus in front or behind the 15cm mark.
A potential problem is sometimes the actual AF sensor is not exactly where it is indicated in your viewfinder.
Never ask the camera to choose your focus spot. I always choose my own with the back selector when I had my D80 and now on my S5.
Shallow DOF can be a limitation or it can be a tool. If f2.8 is too wide then why do so many lust after super fast exotic primes with apertures 2-3 stops faster than f2.8. But I do agree f2.8 may be too wide for a lock and recompose method of shooting at close distances. As others have suggested, I also choose the AF point closest to what I want to focus on, trigger AF with the AF-ON button (not shutter release), recompose a little if necessary then take the shot (shutter release does not trigger AF again..it is disabled on my setup).
Hope that helps a little.

[abitfishy]

Well, I did a very quick ruler test and it seems that it was sharper just in front of the focus mark (as in away from the camera) on the ruler, less obvious at smaller apertures for obvious reasons. Wonder if I do have an issue with the lens/body.

Quick question, I was concerned about the portrait exposure mode making a difference, but I assume the RAW files don't have any of the mode settings in regards to sharpness and saturation etc applied to them?

[farmer_rob]

The RAW files record the mode settings, and apply them non-destructively if you use ViewNX/CaptureNX - and you can then override them if you want (one of the real benefits of using RAW and ViewNX/CaptureNX) before you convert the file to jpeg. Photoshop/ACR does not use the mode AFAIK.

Is it sharper in a consistent manner relative to the focus point? Often the focus points are not as accurately aligned as you might think - which is not a front/back focus issue. Try it with the ruler on various angles.

[abitfishy]

Thanks. Is there any reason I shouldn't turn it off if I am going to PP with Lightroom initially anyway? Thinking of just setting it to Neutral to take any issue of softening (particularly on Portrait mode which I have been using) out of the equation.

[etherial]

Firstly, DON'T GIVE UP. It is solveable, and it is likely to be straightforward. You have a good camera, and good lenses.

It seems to me that ...

It seems that you manage the light and composition well - getting the sharpness is well worth the effort.

Great post Rob, I appreciate the effort you have put into this thread, your advice seems very logical and well thought out to me.

Good discussion everyone, very helpful!

[arthurking83]

Yes, I can do all that with manual selection, but it all sounds too much like hard work.

Single point and recompose seems pretty common, so I should be able to do that. If I keep an aperture that gives me some depth I should be OK.

Or maybe I'll just stick to P&S.

focus and recompose can be difficult to do properly if you don't fully understand it.
Some lenses.. in fact most lenses have what's called 'feild curvature'(look it up to get a good understanding of the term).
What happens when you focus and recompose:

1. you focus at point A(eg. eyes) and use the center spot to do so(in the old, manual days you had a micro prism/split prism to help aid that focusing ability). When you then recompose, you automagically change the distance from the sensor to point A(read up on triangulation theory).
I wish I could draw a diagram for ya, but the topic has been done to death in many books and probably on some websites already, that there's no need to reinvent the wheel! Unless your ability to rotate left to right is absolutely spot on(which, with luck, can be.... sometimes!)you will inadvertently move either closer or further from Point A.
By implication, will recomposing will usually mean placing Point A closer to the edge of the frame. At wider aperutures the thin DOF will make a worlkd of diffference. If you want to use focus and recompose, learn how to best do so, with specific types of gear(ie. lenses).
If the lens is affected with feild curvature, then you're only multiplying the effect of thin DOF+subject to sensor distance error+lens abberations!
2. Lens abberations! While the lens's edge sharpness ability is usually set by the design, it;s not really an abberation, but a simple limitation of the design of the lens. Lens abberations is a different topic, where I previously described how a wide aperture will give that lateral chromatic abberation(the red colouring in one of your fence images). Cheap lenses like the 50/1.8 are made to a price, so you woudl expect a lens like that not to be of the highest calibre in soem respects. have a look at Photozone for an easy to use database of how good/bad lenses can be, in terms of overall performance.
In particular!!!!! have a look at the Tamron 17-50mm f/2.8 review on that link I posted. Why? Because on the 'analysis' page they briefly refer to feild curvature, with a simple diagram so that you can see what effect it can have on your images.
Field curvature is usually not a problem tho.. you should just be aware that it can affect your images. if you're doing flat field work, then FC will be an issue. Flat feild photography is like taking a photo of something that exists only in 2D, like a photo or a page captured from directly in front of the subject.

Bookmark that link and refer to it, as you begin to get a better understanding of gear/technique/etc.. and then it'll all click one day. Don't take those results literally! Use them as aguide to understand your gear better, and go forth and multiply.... your knowledge.

very quickly: farmer_rob described how Picture Control settings work. By default, if you use Portrait sharpness is set to 2, Standard is set to 3 and Vivid is set to 4. it all makes a difference, but usually to the jpgs captured in camera. If you shoot raw, the Picture Control should make no difference to the final result, because as Rob said it can be changed.
One thing i'm not overly impressed with is in camera sharpening and sharpening in ViewNX(CaptureNX's USM is much nicer quality). But you should still get OK quality with using sharening in ViewNX.. but I still think that in camera sharpening is to harsh/coarse.
Set all of the Picture Control sharpening setings to zero, use ViewNX to process your NEF files into TIFF files for further processing in PS/CS/LR. If you want better quality NEFs I suggest using CaptureNX(if you want to maintain them as procesed NEFs that is).

So back to the 50/1.8(only as an example.. this could hold true for any other or all of your lenses!). If you focused from the central focus point on your camera, and then recomposed the scene, then a quick look at the review of the 50/1.8 will show you in an instant, that the edges of the frame when using the 50/1.8 at wide-ish apertures is going to be abysmal(when compared with the centre of the frame). Add that knowledge to your inability to rotate in a perfect arc when you recompose(unless you are a fully automated robot of course! ) and the possibility that the lens is affected by FC.. and the end result will be ... something like a thread asking why your images are not sharp

With 50mm f/1.8. if you use the central focusing point at f/1.8 you should get image sharpness that you will be happy with, at f/1.8, but remember Photozone are in a studio environment, using controlled lighting to maximise the contrast(which is sharpness spelled differently! ) in the image. in harsh light such as sunshine, you'll get more glare andhence loss of contrast(which, remember!... is another way to spell... etc, etc ).

Very few lenses operate optimally at full wide aperture in bright light(they can tho), and the operator will usually have a good knowledge of how to best use that situation and also great PP knowlegde too.
Great lens(in Nikon terms) in harsh light at widest aperture is the Nikon 24-70(that's a lens that you can afford!.. the other ones are generaly the lenses that retail in the $3000+ end of the scale).

So lets asume that the Tammy 17-50 is affected by FC(I hate typing the full term.. it hurts my fingers!). and you want the subject at the edge of the frame, which I've done many times with good to great results with my version... and if the lens is affected by FC, then when you recompose the subject at the edge of the frame is almost certain to be outside the DOF zone.

Now (maybe??)I'm about to introduce an element of envy/regret in your decision of camera body.. and one small and possibly insignificant reason why I sometimes reckon the camera body is more important than the lens when choosing gear.
The D300(and higher) cameras have a focus mode called 3D tracking. This is where you focus and recompose the 'proper way' ... but only when/if it actually works.. which is usually here'n'there. No matter what focus point you choose(and there are 51 of them on the D300 and up models) you focus on the subject, and using AF-C(continuous focus mode) you recompose the frame, and the camera will(should!) keep the subject in the focused area all the time. As you move/pan/tilt fall/stumble/trip/etc the focusing point moves across the viewfinder of it's own accord, still maintaining a single point.
(not the automatic focus point choosing mode in auto auto focusig mode.. D300 and up has that mode too) This focus tracking mode lets you decide the subject(ie. not allow the camera too decide for you) and then helps you to keep track of it.
other alternatives for using focus and recompose is to get an alternative focus screen matte for your D90.

But! If you want to shoot with the subject at the edge of the frame.. now, with the D90, for best focus(sharpness) results you would preselct the focus point that places the subject in the right area(and experience will help there), and:

using AF-C mode; you would focus for a brief moment to allow the camera to settle a little before exposure, then expose.

using AF-S mode(and using the shutter button for both focusing and exposure);- you shouldn't half press(to focus) and then full press(to expose)! Do the full press in one movement and wait for the camera to eventaally take the exposure. Reason is that in the split second that you focus and then expose you are very likely to sway back/forth just enough to get out of focus again. if you press the shutter all the way to expose in one action, the camera takes the exposure in a much quicker split second than you ever could which helps to ensure that the subject distance is where it's supposed to be. using a tripod it should make no difference, but the body naturally sways a little bit, especially when using only one eye, and through a 5x10mm peep hole!
Kiwi mentioned that you should use AF-C mode.. it's a lot better and more consistent(I rarely use AF-S mode.

Your camera has the ability to set the AE-L button(near your thumb) to act as the focusing activation for the camera. Can't remember what setting you need to change to do that, but I highly recommend that mode. What you then do is to set camera to AF-C mode, and use your thumb to activate focusing. The shutter button(called the 'release') will no longer operate the focusing for the camera. Now you focus when you want, and not when the camera wants too, and you're free to shoot as you please. The button falls perfectly to where your thumb probably rests anyhow, so once you're used to it, it feels very natural.

As Kiwi said too, if you're in an area close to any meetups about to happen, it'd be a good point to make it to one and get first hand help from someone that can help.
i reckon that kind of help would be worth a thousand questions, in a forum.