Minolta 50/1.7 Problem

[cykic]

Hi bros,
Wonder if any of u encountered a problem I face with my 50/1.7?

When I use AF with it to shoot a person / object without flash at 1.7-2.0 aperture, the object seem to be blur and some areas around is sharp. What's wrong here? I'm using centre focus mode.

Focusing mode wrong? Positioning of object too far? Camera shake? Aperture? AF problem? lens backfocus problem? etc...

Expert advice pls, thx thx!

[yk200]

hi cykic,

maybe can post some photo for us to see...

[Galdor]

Care to post a picture for us to see? At f1.7 or f2.0 the DOF is very shallow, hence only a small area will be in focus. Could be due to that. Try taking the photo at f8 onwards to see the details.

[Zenten]

Check if your focus point is on the object ........

[boombox]

Well, for example if you shoot with this setting:

50mm f1.7 with a distance of 50cm,

You'd get a depth of field of 0.61cm...

So if you aim at somebody's nose... Chances are... your subject's eyes will go out of focus enough for you notice.

It might help if you distance yourself from your subject: like, at 1 metre, away, the DOF in the above parameters increases to around 2.56cm.

You can also try to stop down the aperture like bro Galdor mentioned. The DOF will extend at the expense of light gathering ability.

[cykic]

Thanks guys for the advice..
Let me get some pics show u soon...

[boombox]

Originally Posted by cykic Thanks guys for the advice.. Let me get some pics show u soon...

No problemo!

I actually got the same problems when I first started - I was doing shoots along orchard road, trying to take in the light from the environment, when I realise, that the DOF at f1.7 is so shallow that part of the face of a subject looked out of focus... but that is if I pixel peep.

[Trigger Happy]

use spot AF, focus lock on your subject (eye, nose, whatever), compose, then commit to the shot.
see my son's pics here, all taken with 50mm f/1.7
http://samuelchan.blogspot.com

[cykic]

Originally Posted by Trigger Happy use spot AF, focus lock on your subject (eye, nose, whatever), compose, then commit to the shot. see my son's pics here, all taken with 50mm f/1.7 http://samuelchan.blogspot.com

Really cute shots! Very sharp and well-composed too.

Thanks bro. Maybe that's why. I was using centre-AF instead of spot-AF.

When u say "focus lock", do u just mean press halfway the shutter right?

[Trigger Happy]

Originally Posted by cykic When u say "focus lock", do u just mean press halfway the shutter right?

yup! one more thing, the closer you are physically to your subject, the smaller that focus area gets, for e.g. if you shoot a face from say 5m away most of it would be in focus, but if you go close like under 1m (some shots of my son were taken really close), then the DOF is going to be so shallow most of it is OOF and getting your subject (eye, nose etc) in focus can be a challenge.

[dr34mc4st3r]

i never use wide-AF...spot AF is my choice for focusing. lol

[eow]

Trigger Happy
the daily blog update on yr baby is very nicely done/narrated

[raincool2005]

Originally Posted by eow Trigger Happy the daily blog update on yr baby is very nicely done/narrated

u interested in baby meh ? i tot u prefer landscapes and still life

[Trigger Happy]

Originally Posted by eow Trigger Happy the daily blog update on yr baby is very nicely done/narrated

thanks bro, but its difficult to upkeep. even like now i need to turn in to catch all the Zs i can, so its tough to edit, resize and post. good thing is this is getting my wife interested in photography - she takes about half of the shots. notice difference in style there?

[cykic]

I'll try out again and repost for advice, if needed.

Thank you all bros for the advice.