coolpix 4500 magnification

[felthad]

Can some one tell me what ratio magnification and the focal lengths give. The range is 1-4 times mag but what lens lengths dothese equal (the coolpix digi lens goes from 7mm to 35mm??). It would help with me working out how the camera powerforms at different distances.
For instance at highest wide angle is the image actaully scaled down like with a 25mm on a conventional lens or is this equivalent to the times 1 mag?
What is the longest focal length it extends to (is it 35mm) then perhaps I can work it out from there...eg - 1*(mag)=7mm, 2*=??mm 3*=??mm and 4*=35mm... like that. The readout on the LCD does not state an acual figure it only shows a bar graph, but in Nikon view software it gives the info.

[stephenB]

Can some one tell me what ratio magnification and the focal lengths give. The range is 1-4 times mag but what lens lengths dothese equal (the coolpix digi lens goes from 7mm to 35mm??). It would help with me working out how the camera powerforms at different distances.
For instance at highest wide angle is the image actaully scaled down like with a 25mm on a conventional lens or is this equivalent to the times 1 mag?
What is the longest focal length it extends to (is it 35mm) then perhaps I can work it out from there...eg - 1*(mag)=7mm, 2*=??mm 3*=??mm and 4*=35mm... like that. The readout on the LCD does not state an acual figure it only shows a bar graph, but in Nikon view software it gives the info.
According to a brochure on the CP4500 from the Nikon website, the lens given focal lengths between 7.85 and 32 mm, which is a factor of 4:1. It also says that this corresponds to a range of 38 - 155mm in 35 mm format. As 50 mm focal length is usually taken as the standard lens in 35 mm film photography, it would appear that the CP4500 is "wide angle" at the lower mags, and "telephoto" at the higher mags.

[felthad]

According to a brochure on the CP4500 from the Nikon website, the lens given focal lengths between 7.85 and 32 mm, which is a factor of 4:1. It also says that this corresponds to a range of 38 - 155mm in 35 mm format. As 50 mm focal length is usually taken as the standard lens in 35 mm film photography, it would appear that the CP4500 is "wide angle" at the lower mags, and "telephoto" at the higher mags.

Thanks so a digtal lens does not scale down magnification at wide angle its just a 1:1. So presumably if I look on nikon view and read the focal length, you can work out how much it is magnifying like this

((focal length/6.0375)+7.85)*magnification of the eyepeice.

[stephenB]

Thanks so a digtal lens does not scale down magnification at wide angle its just a 1:1. So presumably if I look on nikon view and read the focal length, you can work out how much it is magnifying like this

((focal length/6.0375)+7.85)*magnification of the eyepeice.

I dont know where you get the above formula from. It doesnt appear dimensionally correct. If you want a linear equation that relates the nominal CP4500 magnification to the focal length, then I reckon the formula would be

focal length = 8.05 x Mag - 0.2 (mm). This is dimensionally consistent and fits at the 2 mag values of 1 and 4, but I dont know if it true for the intermediate values.

Also, I do not know about how to work out the actual magnification of a 'scope/camera combination - you would need to search the web for info. But I suspect that since, as stated in my first reply, the nominal camera mag of 1 corresponds to less than what you get with a standard lens on a 35 mm film camera, the effective magnification of the camera is less than 1 when at the widest angle setting.

[felthad]

Sorry about the maths mistake, not very good at maths. But what you say about the minimal focal length expalins something. Is I through the scope, put the camera on widest setting then the birds seem to look (relatively) smalller like they have been scaled down. Thanks for the info.


I dont know where you get the above formula from. It doesnt appear dimensionally correct. If you want a linear equation that relates the nominal CP4500 magnification to the focal length, then I reckon the formula would be

focal length = 8.05 x Mag - 0.2 (mm). This is dimensionally consistent and fits at the 2 mag values of 1 and 4, but I dont know if it true for the intermediate values.

Also, I do not know about how to work out the actual magnification of a 'scope/camera combination - you would need to search the web for info. But I suspect that since, as stated in my first reply, the nominal camera mag of 1 corresponds to less than what you get with a standard lens on a 35 mm film camera, the effective magnification of the camera is less than 1 when at the widest angle setting.

[jekatz]

Sorry about the maths mistake, not very good at maths. But what you say about the minimal focal length expalins something. Is I through the scope, put the camera on widest setting then the birds seem to look (relatively) smalller like they have been scaled down. Thanks for the info.


I was directed to this site by digitalbirdy, it allows you to plug in your camera and scope combination and it will calculate a wealth of fun numbers including 35mm equivalent focal lengths.

http://www.jayandwanda.com/digiscope/digiscope_calc.html

It might answer questions you have, maybe even some you don't.

Jon

[felthad]

Just looked at the link, thanks for that.


I was directed to this site by digitalbirdy, it allows you to plug in your camera and scope combination and it will calculate a wealth of fun numbers including 35mm equivalent focal lengths.

http://www.jayandwanda.com/digiscope/digiscope_calc.html

It might answer questions you have, maybe even some you don't.

Jon