How to caculate focal lenght?


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digi~ET

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#1
A40's close up is 26cm, if i use a macro lens [+10], then what will it be?

I also got +3 close up.........same calculation?

couldn't get a gd pic~~~ using the +10........most images seems OOF~~~.......may be like .....the er ....who ...just said......is becos of my hands?
 

denizenx

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#2
Originally posted by digi~ET
A40's close up is 26cm, if i use a macro lens [+10], then what will it be?

I also got +3 close up.........same calculation?

couldn't get a gd pic~~~ using the +10........most images seems OOF~~~.......may be like .....the er ....who ...just said......is becos of my hands?
ok try to aim with LCD, move back and forth across the subject... if at any point the subject pops into focus u know u're almost there... then stop down your cam, ie turn aperture to something really tiny like f11 and take a shot at the sharp spot... if your hand shakes badly, try a tripod + timer or practice on the table top first...
but A40 dun have much zoom think maybe you try to movecloser than 26cm..
 

digi~ET

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#3
Originally posted by denizenx


ok try to aim with LCD, move back and forth across the subject... if at any point the subject pops into focus u know u're almost there... then stop down your cam, ie turn aperture to something really tiny like f11 and take a shot at the sharp spot... if your hand shakes badly, try a tripod + timer or practice on the table top first...
but A40 dun have much zoom think maybe you try to movecloser than 26cm..
but if shooting insects how to use tripod???
why use f11??? i tot need to use bigger aperture like 2.8 to get the sharp spot with the background blur. ??
 

Newbie123

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#4
Originally posted by digi~ET


but if shooting insects how to use tripod???
why use f11??? i tot need to use bigger aperture like 2.8 to get the sharp spot with the background blur. ??
Using a closeup filter will result in a shallower DOF, so using a small aperture will compensate for it (You will still get blur background though :D). Using a +4 closeup, the focus distance is 100 / 4 = ~25 cm and +10 is 100 / 10 = ~10cm. Also with a closeup filter, you need not use the macro mode of your cam. Just zoom in all the way :D Hope this info helps
 

digi~ET

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#5
Originally posted by Newbie123


Using a closeup filter will result in a shallower DOF, so using a small aperture will compensate for it (You will still get blur background though :D). Using a +4 closeup, the focus distance is 100 / 4 = ~25 cm and +10 is 100 / 10 = ~10cm. Also with a closeup filter, you need not use the macro mode of your cam. Just zoom in all the way :D Hope this info helps
no matter what camera i use...just take 100/10 ?
 

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