Normal Perspective Lens.

[fotogenik]

Okay, Very shortly I am buying what is considered to be a "prime" lens. By Prime I am talking about a single focal length lens that is of "normal" perspective. What I am attempting to figure out is, what is considered normal perspective?

I know normal perspective is considered to be what a person sees through their eyes. I have heard this equated to 50mm. I also know that with digital camera's there is a cropping factor that comes into play (maybe the correct term is focal length multiplier instead)

For my D50 I know that the foacal length multiplier is 1.5.

Therefore if I purchase a 50mm Nikkor lens and put it on my d50 does it in essence become a 75mm lens? If so should I really be considering a 34 or 33mm (based upon calculations) lens in order to come out with a 50mm focal length after the multiplier is taken into effect?

Thanks

 

[markc]

Correct. You would look for a 35mm lens if you wanted a prime that was "normal". (BTW, prime is any lens that is a single focal length.)

 

[fotogenik]

Correct. You would look for a 35mm lens if you wanted a prime that was "normal". (BTW, prime is any lens that is a single focal length.)

Thanks a bunch for the quick reply.

Part 2 of this now that I have that understanding is....

For portraiture photography and things of that nature should I be looking at lenses that are a little narrower than normal such as a 50mm lens wich on my d50 actually becomes a 75mm lens? It appears that many who do portrait photography use a slightly zoomed in prime lens such as a 50 or 85mm lens which on my camera works out to a 75 or 125mm lens in order to do that type of photography.

I understand the "normal" lens would be good for group shots but for shots of a single person or maybe a couple would I want it to be zoomed in some for the most part?

 

[markc]

It's usually best not to go below normal when shooting portraits, unless you want facial distortions. A lot of people shoot in the 80-130 range. For the 1.5 and 1.6 digital cameras, the 50mm and 85mm lenses turn out to be perfect. I do over 99% of my shooting with a 50mm/1.4 and an 85mm/1.8 on a 10D.

 

[fotogenik]

Thanks a bunch, you have helped me greatly in figuring out why I hear 50mm and portrait connected so often.

 

[markc]

No problem. If you want to see what portraits are like using a normal lens, check out Henri Cartier-Bresson's Tête á Tête. In his case, it's a 50mm lens on a Leica 35mm rangefinder.

 

[fotogenik]

with that arrangement there is no multiplier correct? A 50mm lens is truly 50mm focal length?

 

[xion]

I shoot portfolios with my zoom lens between 70 - 120mm on a 35 mm film camera. On my D70s, I either shoot with 50mm 1.8 or a zoom 35 - 70mm. I have tried with higher zoom ratio but the faces come up two dimentional.

 

[markc]

with that arrangement there is no multiplier correct? A 50mm lens is truly 50mm focal length?

Correct. And you'll see that his portraits are what's called environmental portraits, where the environment the subject is in takes part in the image. Getting up close to take a typical head and shoulder shot with a normal lens can be uncomfotable for the subject and also increases the likelihood of distortion.

 

[Torus34]

Traditionally, normal lenses were those with a focal length roughly equal to the diagonal dimension of the film frame. For 35mm [1x1.5"], 45.8mm. For 6x6cm [120/620 film], 81mm. With time, 35mm rigs settled on 50mm as the 'standard' lens while 6x6's ran 75 or 80mm.

A good 'portrait' lens should have a long enough FL that you're not in the sitter's face while still being able to fill the frame with head & shoulders and enough aperture to permit blurring the background. For 35mm, lenses 85 to 95mm were considered suitable for portrait work.