1. ## Lens/Zoom

To all Veterans out there,

Scenario: There's a subject that Peter would like to take a picture of. However, it is too far away. How should Peter decide what lens to buy to achieve the zoom that he need?

2. ## Re: Lens/Zoom

He should decide by calculating which lens will allow him to maintain a positive balance on his bank account.

3. ## Re: Lens/Zoom

Originally Posted by desmondnwj
To all Veterans out there,

Scenario: There's a subject that Peter would like to take a picture of. However, it is too far away. How should Peter decide what lens to buy to achieve the zoom that he need?

Check :

a) is it possible to get closer to the subject?

b) is it possible to use a TC to get the range required at the expense of the aperture loss.

c) buy a long lens which can allow you to reach the distance required, budget willing...

d) buy a long lens with a TC to get the range required (cheaper than a full long lens) i.e.
70-200 f2.8 with a 2x TC would be cheaper than getting a 400mm f2.8. But you lose 2 stops of light and get a 140-400 f5.6 instead...

4. ## Re: Lens/Zoom

Rashkae: Can assume "he" is beri rich =]

zac08: Thanks for your valuable feedback. From a layman point of view, I was wondering if say a pigeon is 50m away what spec of lens can home in on it and cover about 50% of the picture. Is there a formula for this (size of object, distance away, size on picture)?

5. ## Re: Lens/Zoom

Originally Posted by desmondnwj
Rashkae: Can assume "he" is beri rich =]

zac08: Thanks for your valuable feedback. From a layman point of view, I was wondering if say a pigeon is 50m away what spec of lens can home in on it and cover about 50% of the picture. Is there a formula for this (size of object, distance away, size on picture)?
Let's just average a pigeon at about 40cm long. To get this inside 50% of the image sensor, you'd need to know the sensor size, the focal length as well as the angle of view.

According to a calculation website I visited, 2796.8 mm would be required to get it fully in view. So Half of that would be 1350mm or so...

you got the dough for a 1000mm lens?

PS : this calculation was done on a Nikon 1.5 x crop DSLR. So if you are calculating it on a different system, pls try it again here :

http://www.cambridgeincolour.com/tut...era-lenses.htm

6. ## Re: Lens/Zoom

zac08: You are a serious photographer! Thanks for spending the time explaining. Conclusion, unless you are a fifthly rich, use a high res camera to capture than digitally enlarge from there and crossfingers that you got the details

7. ## Re: Lens/Zoom

Originally Posted by desmondnwj
zac08: You are a serious photographer! Thanks for spending the time explaining. Conclusion, unless you are a fifthly rich, use a high res camera to capture than digitally enlarge from there and crossfingers that you got the details
No, never digitally enlarge, you'll make it look grainy. Crop crop crop!

(yes, this is where megapixels does matter)

8. ## Re: Lens/Zoom

Originally Posted by desmondnwj
zac08: You are a serious photographer! Thanks for spending the time explaining. Conclusion, unless you are a fifthly rich, use a high res camera to capture than digitally enlarge from there and crossfingers that you got the details
There is a 1700mm prime by zeiss and a 1700 - 1200 zoom by nikon

Actually there is a limit to having more MP for ur sensor. apart from noise the lens might even be outresolved.

Ryan

9. ## Re: Lens/Zoom

Rashkae: ahhh... "I must crop, I must crop, I must croppppp....."

giantcanopy: Thanks for insights!

Anyone tried placing camera to a telescope? maybe I am digressing

10. ## Re: Lens/Zoom

Yea, astrophotography =P

11. ## Re: Lens/Zoom

I dun mean specialize equipment. Literally, 1 x camera and 1 x telescope.

12. ## Re: Lens/Zoom

Originally Posted by desmondnwj
I dun mean specialize equipment. Literally, 1 x camera and 1 x telescope.
Yes... all you need is a adapter for the telescope to fit the camera.

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