Will the 50mm prime be 75mm on my zoom?

I want to buy a prime, 50mm from eBay for $180. However I have a Nikon d5300. Will the 50mm be like the 75mm on my 18-140 or 50mm? I've heard the 50mm is great for portraits etc but 75mm on a zoom lens is really close. I've looked up portrait shots on images and to get that close on 75mm id have to stand about 10 metres away… Thanks

50 mm is 50 mm.

75 mm is 75 mm

If you want to see what the angle of view is of a 50 mm lens, set your 18-140 mm to 50 mm.

When people call a 50 mm the same as a 75 mm on a full frame camera, they are talking about the angle of view, not that the focal length of the lens actually changes.

Now you can see why buying an 85 mm "portrait" lens does not work well unless you have a full frame camera like the Nikon D610, D800 or D4

10 metres is just too far away to be able to direct a model or subject

"Will the 50mm be like the 75mm on my 18-140 or 50mm?

It'll be the same field of view as if you set your 18-140mm lens to 50mm.

Common portrait lenses are 50mm, 85mm and 135mm. Which one you use depends on how much space you have & how much you want in the frame (head & shoulders, 3/4 body or full body).

I use all these on a crop sensor body. I also use a 24-70mm f2.8 for portraits as well.

Unless you also own a full frame DSLR or a 35mm SLR then just forget that crop factors even exist. Their only use is for comparison of lens performance across different sensor sizes.

Your camera has a crop factor of 1.5x

So 50 x 1.5 = same angle of view as a 75mm (full frame equivalent).

On your camera, a 50mm prime lens is almost perfect for portraits. No you won't be too close. The whole idea for taking good portraits is to get further away from the subject.

With a 50mm lens on a cropped sensor camera you only need to stand about 2 or 3 metres away to get a head shot.

75mm on a zoom on your camera would give you the equivalent angle of view that a 116mm would have on a full frame camera. That would be too close, and you would need to step back a considerable distance.

A 50mm prime will look exactly the same as the 50mm setting on any zoom lens, if it is used on the same camera. End of story.

The confusion arises because old film SLRs and "full frame" (expensive) DSLRs have physically bigger sensors than low to mid price DSLRs such as a D5300. In the old days 50mm was considered "standard" for film, but it works "longer" on your D5300, and thus has the efffect that a 75mm would have on a film SLR.

I respectfully disagree with the posters that say that the effect is the same; the only thing that is the "same" is the angle of view but NOT the finer image details that the prime lens will ultimately yield. First, prime lenses are normally "faster;" so that's one difference right there. Second, prime lens will yield greater image detail than the 50mm setting of a zoom lenses BECAUSE zoom lenses can't yet achieve the image detail as prime lenses… Prime lenses are simply superior in fine image detail. While some lens brand names are known for superior quality glass elements among prime and zoom lenses, prime lenses are KNOWN for their crisper, superior image details; it's "the nature of the beast," or the result of engineering problems yet to be solved even with our computer advances. Our modern computerized robotics alongwith our computerized engineering have made zoom lenses commonplace and are popular because of the ease of use, and the convenience of allowing us to stand on one spot yet get different focal lengths from the one lens BUT lens manufacturers throughout the world have yet to produce a zoom lens with the same superior quality of image details of prime lenses. Yes, zoom lenses HAVE become more affordable through the use of robotics and computer tech advancements, but due to the moving parts can't yet achieve the same fine details as the prime, static focal length PRIME lenses.