Do i need to bring this 50mm f1.8 to calibrate?


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I tested the following at 1.4 with different ISO & adjusted the shutter speed accordingly:sweat:, it seem that with higher ISO, the focus point go sharper at the eyes & lips.This may not be true.Just a test.Sudject size 5 by 2+ cm


At iso 100
DSCF4367.jpg


At iso 200
DSCF4368.jpg


At iso 400
DSCF4369.jpg
 

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After looking thru your pic again (TS) , look ok , eyes are sharp leh
 

It could be your focussing technique. Take a shot of a chart or a calendar at f1.8 and show us.
Ok i change the subject to another.
Also as other brothers mentioned, i also went through the manual and read around and made some setting changes. Here is result

Focus point is at nose (and dead on)
img01.jpg

Focus on cell
img02.jpg

Focus on Logo
img03.jpg

Tries focusing on eye but auto cannot do it, but i tried manual and it was able to focus (may be eye is to small).
img05.jpg
 

i also got a 50mm 1.8...
only last weekend then i learnt how to focus it...
just a few minutes work...
same object same focus then snap at f1.8, f2.8, f4, f5.6, f 6.3, f9, f13, f16, f22....
found out f2.8 n f4 produces the better image..f1.8 u have to be very precise with ur subject...
a bit close or a bit far n u lose ur point of focus...tats wat i found out..
 

i brought up this topic last year. Covered this talk with NSC as well. Nothing much you can do abt it. AF FIne tune also cannot help much.

The only way is to leave with it and to shoot at F4 at least (its amazingly sharp at F4 - F 11).
 

Thank you all who input, it helped me a lot to understand 50mm lens.
Now trying to hunt 50-500mm sigma :D.
 

i brought up this topic last year. Covered this talk with NSC as well. Nothing much you can do abt it. AF FIne tune also cannot help much.

The only way is to leave with it and to shoot at F4 at least (its amazingly sharp at F4 - F 11).

new to photography...but if we shoot at f4 then the bokeh will be small(not much) rite?
cos i also tot of buyin this for its bokeh effect..

pls enlighten...thanx...
 

new to photography...but if we shoot at f4 then the bokeh will be small(not much) rite?
cos i also tot of buyin this for its bokeh effect..

pls enlighten...thanx...

yeah... actually we all buy big aperture lens to use them... However note this thing call MTF. Its the optimum aperture for each type of format, i,e 35 mm is F5.6- F8 and for MF, it is F8 to F 11. Those technically incline, pls chip in the info.

I love the 50mm 1.8. I use it at low lighting only.
 

There is a internet article on 50mm f1.8. The sharpest focus is at f6 to f8, before the diffraction kick in. enjoy:)
 

F4 is quite sharp...f2.2 is also not bad if the light is not too much diffusive.

20090820_409023bb1eb10553b23fR7yuSUiYfuxf.jpg.thumb.jpg


20090820_a1eb33f49787582a6906bW9qkOtVD82p.jpg.thumb.jpg
 

perhaps one more reason. u exceeded the minimum focus distance. i see u are trying to take pretty small objects, naturally u tend to go nearer to fill the frame. try moving back a little bit. ;) i hope this help.
 

i brought up this topic last year. Covered this talk with NSC as well. Nothing much you can do abt it. AF FIne tune also cannot help much.

The only way is to leave with it and to shoot at F4 at least (its amazingly sharp at F4 - F 11).

Couldn't agree more. I get sharp images mostly at f2.8 - f4. And I only used f1.8 for delicate abstract composition. Imagine using a f1.2 lens for portraits! Pretty difficult to get an ideal result if you ask me.
 

Pls also check if you are shooting within the minimum focusing distance.
 

They say the sweet spot of the 50mm f/1.8 is actually at f2.8. maybe you could try that more extensively?
 

Since we are talking about focusing here, i would like to know do we really need to press "AE-L/AF-L" after focus is fixed inorder to recompose the pic??

According to the manual p54, it mentioned that in AF-A and AF-C we need to press "AE-L/AF-L" , while in AF-S half press will do. Somehow when i tested on my D90, in any mode (AF-A, AF-S, AF-C), i dun really required to press "AE-L/AF-L". I can recompose the pic quite well.
 

Ok i change the subject to another.
Also as other brothers mentioned, i also went through the manual and read around and made some setting changes. Here is result

Focus point is at nose (and dead on)

Focus on cell

Focus on Logo

Tries focusing on eye but auto cannot do it, but i tried manual and it was able to focus (may be eye is to small).
can tell you are doing the focusing test using hand held.

download the chart and set up the test accordingly. if it is have focusing issue, can bring the test image to NSC see what can they do.

had similiar problems with my 35mm lens recently and i did a test using this chart http://focustestchart.com/chart.html

everything's fine actually.
 

please not that the af sensing area is not just the small little box you see in your vf, the alignment of the actual sensor is always not in spot on precision and the area is slightly larger than the box you see.

you will never know which is the spot the AF sensor actually picks, since it will just that the line with higher contrast feedback threshold. just go outside and shoot some pictures, if you cannot notice it, then it is within range. lol
 

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