What is fixed focal length

Out of ignorance, in no words what qualifies as fixed focal length photo?

In the NO WORDS forum, a Fixed Focal Length photo is one that was captured using a prime lens -- at least, that's how I understand it.

That is pretty much how I also understand the meaning in regards to the No Words Forum: although I am reasonably sure any images I contributed to those threads were from my Fuji x100s - which is truly a 'fixed focal length' camera.

 

I think that you won't ruffle any feathers if you use a Prime Lens on a camera that has an interchangeable lens system.

 

WW

I think a Tri-Elmar would be ok.

Out of ignorance, in no words what qualifies as fixed focal length photo?

In casual parlance, a fixed focal length lens is not a zoom lens, and vice versa.

 

Is one better than the other? It depends. Fixed (prime) lenses are often better optically than zoom (variable) lenses. Zoom lenses are often lighter than the prime lenses they replace, and allow cropping in the camera. I have three zoom lenses which cover focal lengths from 16 mm to 200 mm, with overlap. It would take 7 or 8 primes lenses to cover that range in conventional increments, at twice the weight and three times cost, at comparable image quality and build.

Edited June 29, 2018 by Ed_Ingold

Fixed focal length is as it says. A lens that has only one focal length as opposed to a zoom lens that has a range of focal lengths. Another way of saying fixed focal length is "prime' lenses.

Thanks, over half of my photos are fixed fixed focal length. I just wanted to make sure before i posted on the thread that I had it right. It seemed simple enough. Just wanted to make sure I was not missing something

There are some technical issues in using the term "prime" lens, which is probably why the "fixed focal length" terms was used instead.

 

In any case, as said, a lens that is not a "zoom" lens.

A repaired lens.

I was, perhaps, over thinking the "fixed" focal length designation in favor of "not zoom". That is because many lenses shorten the focal length as the subject the nearer the camera, in order to reduce the motion required for internal and/or auto focus. For example, a nominally "prime" lens, a Nikon 105/2.8 AFD Micro has a focal length 68 mm at its closest point. Of course, zoom lenses do exactly the same thing, but that falls in the category of "variable" focal length. Technically, most photos with a zoom lens are taken at a particular, or "fixed" focal length. Word-parsing is getting out of hand.

A photograph captured with an iPhone would be a great example of a fixed focal length photo.

but the I phone has a feature that mimics a zoom lens. Considering the intent of the forum it should not qualify

The cell phone camera should be included as fulfills most of the tenets: small, light, un-intrusive, relatively cheap. Besides, I like viewing Brad's Citysnaps.net. street photography.

But is it fixed focal length? Not trying to cause trouble, just a consistent definition I remember the semantical arguments between JDM and de Bakker. By the way does anyone know what happened to de Bakker?

My weekly thread, I get to bend the rules...ah, the feeling of power.

but the I phone has a feature that mimics a zoom lens. Considering the intent of the forum it should not qualify

 

This is so silly. Jeeez...

 

So a photo I made with my Canon 6d and 35mm/1.4 fixed lens, and cropped afterwards in LightRoom, thus mimicking a zoom lens, should not qualify a photo as well, right?

 

 

"But is it fixed focal length?"

 

Of course it is, around 32mm. You might not be aware that "digital zoom" is done in software, similar to cropping in post. And does not change the focal length or the physical aspects of the lens.

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He’s at a loss for words......;)

I have a lens that has two focal lengths, but isn't zoom. You choose one, but nothing in between.

 

It is a Soligar Dual Focal 28/35.

I was, perhaps, over thinking the "fixed" focal length designation in favor of "not zoom". That is because many lenses shorten the focal length as the subject the nearer the camera, in order to reduce the motion required for internal and/or auto focus. For example, a nominally "prime" lens, a Nikon 105/2.8 AFD Micro has a focal length 68 mm at its closest point. Of course, zoom lenses do exactly the same thing, but that falls in the category of "variable" focal length. Technically, most photos with a zoom lens are taken at a particular, or "fixed" focal length. Word-parsing is getting out of hand.

 

The definition of focal length is, pretty much, for an object at infinity. (Or with a collimated light source.)

 

But yes, the quantity that we think of as focal length, as regards to filling up the frame, does change.

 

Also, f/stops relate to the focal length, but the amount of light reaching the film decreases as the lens to image distance changes.