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-   -   How do they work? (https://forums.steves-digicams.com/add-lenses-49/how-do-they-work-21099/)

sTeVEn_au Feb 26, 2004 6:25 AM

How do they work?
 
I am looking at buying the Canon Powershot Pro1 (and the add-on lenses) when it comes out, but so far I have only had little pocket cameras so I have no experience with add-on lenses. So I have a few questions:

Do any of the lenses (telephoto, macro and fish-eye) result in a circular photo, requiring software to straighten it out?

Can I combine a telephoto lens with the camera's built in optical zoom both at the same time? (I assume a camera with 7x optical zoom and an add-on telephoto lens should be able to zoom to 7 times the capability of the telephoto lens' own magnification?)

How does an add-on macro lens work in comparison to a camera's own macro mode (in terms of distance between the lens and the subject, and amount of detail) ? The Powershot Pro1 has a macro mode of about 10cm, and a super-macro mode of 3cm, yet the super-macro mode reduces the image size from 8mp to 5mp. So if I was to attach the add-on macro lens, would I still be able to get 8mp close-ups with even better magnification than the 5mp super-macro mode? Does a macro lens mean better magnification from a greater distance?


By the way, when can we expect the full review of the Pro1? I'm wetting myself in anticipation....

KevinG Feb 26, 2004 5:17 PM

Re: How do they work?
 
Quote:

Originally Posted by sTeVEn_au
I am looking at buying the Canon Powershot Pro1 (and the add-on lenses) when it comes out, but so far I have only had little pocket cameras so I have no experience with add-on lenses. So I have a few questions:

Do any of the lenses (telephoto, macro and fish-eye) result in a circular photo, requiring software to straighten it out?

For tele and macro lenses of good quality you should not see any distortion. Poor quality lenses will cause out of focus images, color fringing, variation in focus (ie, center in focus but corners not).

Wide angle lenses will cause 'barrel distortion'... causing straight lines in the image to appear curved around the center. In general the stronger the wide-angle lens the more distortion you will have. The fish-eye lens is an extreme example of a wide-angle lens... it will cause a great deal of distortion, but usually this is desired for the artistic effect. Software can correct minor barrel distortion.

Quote:


Can I combine a telephoto lens with the camera's built in optical zoom both at the same time? (I assume a camera with 7x optical zoom and an add-on telephoto lens should be able to zoom to 7 times the capability of the telephoto lens' own magnification?)

Correct.

Quote:


How does an add-on macro lens work in comparison to a camera's own macro mode (in terms of distance between the lens and the subject, and amount of detail) ? The Powershot Pro1 has a macro mode of about 10cm, and a super-macro mode of 3cm, yet the super-macro mode reduces the image size from 8mp to 5mp. So if I was to attach the add-on macro lens, would I still be able to get 8mp close-ups with even better magnification than the 5mp super-macro mode? Does a macro lens mean better magnification from a greater distance?

No, the macro lens doesn't increase magnification at a greater distance, it changes the focal length of the lens so that you can focus at much closer distances.

So, the answer to your previous question is yes... with a good macro lens you would be able to take extreme closeups... probably less than 4-5cm (depends on the lens) and you could use the full 8mp setting.

I don't know anything about the supermacro mode but it sounds like it is cropping the center of the image (?).

Quote:

By the way, when can we expect the full review of the Pro1? I'm wetting myself in anticipation....
No idea ;).

Kevin

sTeVEn_au Feb 27, 2004 3:59 AM

Cool, thanks, now I am a bit clearer about it.

So basically if a camera has a 10cm macro mode, then I add a extra macro lens, I can just move closer to the subject than the original 10cm? I thought it might mean that I could still only stay at 10cm but get a lot more magnification and detail.


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