close v's distant shots

[mikeysaling]

have a d5100 - close ups are much sharper than distant with all lenses - is this normal or have i a prob with the camera ie back or front focussing?

 

[TCR4x4]

have a d5100 - close ups are much sharper than distant with all lenses - is this normal or have i a prob with the camera ie back or front focussing?

Distance you have a lot against you. Atmosphere being the main one. Heat, haze and dust will reduce the apparent sharpness of an image.
Also quality of lenses will have a huge impact. There is a reason why good long lenses are so expensive.
If you are shooting with a cheap 70-300 and trying to photograph something a long way away, you are fighting a loosing battle.

 

[ziggy©]

Very difficult to tell. The only way someone can tell is if you post an example picture with the EXIF intact showing settings you used when you took the shot.

 

[mikeysaling]

tx 4x4 - if it gets good focus close - does that mean the focus is good throughout the range ? ie clse to distant - ? ie locks on but at about 100ft images are a bit iffy. could it be the camera or the lenses

 

[mikeysaling]

ok here is the cat image - the post is sharper than the cat - focus right on cats nose

By mikeysaling at 2012-05-16

 

[TCR4x4]

tx 4x4 - if it gets good focus close - does that mean the focus is good throughout the range ? ie clse to distant - ? ie locks on but at about 100ft images are a bit iffy. could it be the camera or the lenses

Depends on your aperture. If you have an aperture of say f/3.5, only a tiny portion will be in focus. To get more in focus, you need a narrower aperture.
That cat shot just looks like slightly missed focus.

To asertain if its a close/backfocus fault, you need a much more controlled environment to test it, as otherwise its very hard to tell.

 

[simonblue]

Distance you have a lot against you. Atmosphere being the main one. Heat, haze and dust will reduce the apparent sharpness of an image.
Also quality of lenses will have a huge impact. There is a reason why good long lenses are so expensive.
If you are shooting with a cheap 70-300 and trying to photograph something a long way away, you are fighting a loosing battle.

Adgree,but sometime you can use it to your advarage,I was taking some shots in Aus,an mining town,the heat dust & haze,made lovely sunset,it was just stunning

 

[mikeysaling]

Tks 4x4 -alllenses do the same close up fine - the further away the prob magnifies - the focus on cat was (as per the software) spot on the nose ! maybe its the cam - anyway ive ordered a 7000 for daily fun - the 5100 is really for work on a copy stand and is fine in view mode.

 

[NikkiA]

the focus on cat was (as per the software) spot on the nose !

I think that's the problem... The EXIF doesn't tell us the distance to the subject, but I'm guessing it was around 6', at which point, with f/5.6 you're only going to get a little under an inch of DOF in each direction (about 1/20th of a foot, by my reckoning). The nose is going to be the forward most point, and is about on the same plane as the fence/gate post. So the post being in focus sounds fair, and DOF probably extends no further than just in front of the cat's eyes. The nose being the forward-most point on the cat, in that pose, means that you're only really utilising the rear portion of the DOF.

If you'd focused on the cat's eyes (or just between them) then it'd probably have been a much better focused result, and the majority of the cat would have been closer to being within the DOF.

Edit: focusing on the ears might have been even better, you'd get more of the cat's body in the DOF, and the eyes would be close enough to be sharp. But you might risk the nose being too out of focus, and the viewer focus is probably going to be on the cat's face more than the body, so...