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Ujjwal Mukherjee
BetterPhoto Member Since: 3/21/2001
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Effect of Variable Zoom on Exposure


Hello,

I would like to know whether there is any effect of Variable Zoom on the exposure setiing. Will explain this with an example. I had used my Canon 28-80 USM ( f/3.5-f/5.6) variable zoom at it's 28 mm setting and took a snap of
a landscape with a subject using the camera's( EOS 50 ) meter reading and the picture (print) came very good but another snap which I took in the next shot by zooming to 80 mm on the same subject again and the result was a dark(underexposed ?) picture.I again used the camera meter reading.

Now if I don't want to use teh camera meter reading (assuming something is going wrong ) and say I want to use Sunny 16 rule and shoot with 28 mm
lens with f/16 and 250 shutter speed
(ISO 200 film )of a subject and then want to take the snap again by zooming to 80 m.m of the lens of the same subject and under the same lighting condition do I need to make any changes from teh earlier setting ( f/16 and 250 shutter speed )that is can I retain teh same exposure setting that I used with 28 mm lens.

Thanks in advance.


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4/19/2001 1:28:55 AM

 
Ujjwal Mukherjee
BetterPhoto Member Since: 3/21/2001
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  Hello John/Jeff,

I will be very grateful if someone can help me with an explanation for the above mentioned incident. I am leaving for Europe for a holiday and will get many such similar instances when I'll have to Zoom in to a subject and scared of getting any similar results as the one I had mentioned above. Forgive me
for being impatient

ujjwal


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4/23/2001 7:27:04 AM

 
Ujjwal Mukherjee
BetterPhoto Member Since: 3/21/2001
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  Hello John/Jeff,

I will be very grateful if someone can help me with an explanation for the above mentioned incident. I am leaving for Europe for a holiday and will get many such similar instances when I'll have to Zoom in to a subject and scared of getting any similar results as the one I had mentioned above. Forgive me
for being impatient

ujjwal


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4/23/2001 7:27:14 AM

 
Jeff S. Kennedy   I haven't responded to this because it puzzled me. Your camera's meter should be making the adjustment to the different focal lengths. All I can say is that if this is a consistent problem then you just need to make the adjustment yourself by compensating when you zoom by adding a 1/2 stop. If you are shooting negative film it wouldn't hurt to just rate it a stop slower and give yourself some breathing room. Chances are that the differences you are seeing are only because the printer operator at your lab isn't making the right adjustments any way.


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4/23/2001 12:08:20 PM

 
Elaine S. Robbins
BetterPhoto Member Since: 7/14/2000
  Ujjwal -

You mentioned that you'll be going on holiday and using Zoom a lot....My advice is DON'T be afraid to get close to a subject. Granted, sometimes you need to exercise caution, but you'll find you're a lot more creative if you don't slave yourself to the zoom. It could also lead to some more interesting photo opportunities. Children, in particular, often like to clown for the camera, and these pics can turn out even better that truly "candid" ones. At political protests, protesters often like to get attention and probably won't mind and may do something interesting if they see you approaching with a camera (though I'd stick to strictly PEACEFUL protests, and be careful if you go someplace like Russia, which has some anti-Western tendencies, or anywhere in the Middle East). See my above comment on the photo I took of the statue regarding the way zoom changes perspective. Have fun on your holiday!

Elaine


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4/23/2001 8:27:37 PM

 
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