50mm - what is it?

[Liz]

Now that I have an Olympus 25mm prime, I have a question regarding the threads that refer to posting 50mm images. With the different sensors/cameras 50mm can equal different focal lengths. IOW - if we are talking 35mm equivilant example:

My XTi at 50mm = 80mm
EP-1 @ 50mm = 100mm
FF @ 50mm = 50mm (I believe)
P&S - not sure

The goal of this post is to get me the "official authorization" to post images from my new Olympus 25mm/f2.8 lens (which actually equals 50mm) in the wonderful 50mm threads here! I hope Old Timer will vote "yes."

Otherwise I will have to invest in a 50mm lens for my E-P1..........

Liz

[realart]

The goal of this post is to get me the "official authorization" to post images from my new Olympus 25mm/f2.8 lens (which actually equals 50mm) in the wonderful 50mm threads here! I hope Old Timer will vote "yes."

Otherwise I will have to invest in a 50mm lens for my E-P1..........

Liz

While new here I noticed this in the other 50mm lens thread and actually substituted the word "prime" for 50mm in one of my replies.

50mm is "normal" for 35mm, telephoto for many digital, wide angle for 2 1/4 square etc.

I think the term "normal lens" or even "normal prime lens" makes a lot more sense. "50mm" really makes no sense unless it is in a thread that is about a specific film or sensor size.

[mjs1973]

It's an interesting question Liz. I believe the original intent of that thread was for people to share images taken with the very inexpensive 50mm f/1.8 lens. If it's the thread I'm thinking of the Larry started, the title says "50mm f/1.8 thread". Of all the members who have posted in that thread I would think that the vast majority are using DSLR's with less than a full frame sensor, so very few of those images are being shot at the 35mm equivilant of 50mm's.

That being said I'm sure there are posts in that thread that were shot with other versions of a 50mm lens. It's been a while since I looked at that thread but I would bet there are images taken with the 50mm f/1.4, f/1.2 and maybe even the f/2.5 macro.

[Franglais]

I'm in the same situation as Liz with my 35mm f1.8. It is a "normal view prime" lens for the APS-C format. It has many of the advantages of the 50mm f1.8 primes that people most often use when they think "nifty fifty":

- low price
- excellent image quality
- wide aperture
- compact
- very limited depth of field when you open it up to full aperture

As Liz says it doesn't give the same moderate telephoto view as a 50mm on an APS-C camera which is what most people are using nowadays. It gives a normal view, like Liz's 25mm on her Olympus.

I would be rather curious to see what Liz can do with the 25mm..

[Liz]

It's an interesting question Liz. I believe the original intent of that thread was for people to share images taken with the very inexpensive 50mm f/1.8 lens. If it's the thread I'm thinking of the Larry started, the title says "50mm f/1.8 thread". Of all the members who have posted in that thread I would think that the vast majority are using DSLR's with less than a full frame sensor, so very few of those images are being shot at the 35mm equivilant of 50mm's.

That being said I'm sure there are posts in that thread that were shot with other versions of a 50mm lens. It's been a while since I looked at that thread but I would bet there are images taken with the 50mm f/1.4, f/1.2 and maybe even the f/2.5 macro.

I agree - about the original intent. I did get "special permission" to post a few from my 50mm/f1.4.......

Liz

[Liz]

I'm in the same situation as Liz with my 35mm f1.8. It is a "normal view prime" lens for the APS-C format. It has many of the advantages of the 50mm f1.8 primes that people most often use when they think "nifty fifty":

- low price
- excellent image quality
- wide aperture
- compact
- very limited depth of field when you open it up to full aperture

As Liz says it doesn't give the same moderate telephoto view as a 50mm on an APS-C camera which is what most people are using nowadays. It gives a normal view, like Liz's 25mm on her Olympus.

I would be rather curious to see what Liz can do with the 25mm..

Charles,

Believe it or not, I purchased it before vacation, but didn't use it on vacation. I'm taking it out for the first time tomorrow. It better work because the return period is long gone! Never did this before.

However, I'm looking forward to seeing what kind of images this lens produces - for $224!

Liz

[Liz]

While new here I noticed this in the other 50mm lens thread and actually substituted the word "prime" for 50mm in one of my replies.

50mm is "normal" for 35mm, telephoto for many digital, wide angle for 2 1/4 square etc.

I think the term "normal lens" or even "normal prime lens" makes a lot more sense. "50mm" really makes no sense unless it is in a thread that is about a specific film or sensor size.

With the new M4/3 system - and other options probably becoming available as sensors are improved, it gets more interesting.

Thanks for your input. This is becoming an interesting topic and I'm looking forward to seeing what others have to add.

Liz

[xystren]

Here's my two cents worth on the topic:

The thing to remember, a 50mm lens is still a 50mm lens, regardless of the sensor/media type. The crop factor is not affecting the focal length which is what the 50mm is referring to.

In the past, since 35mm (or what became the de-facto full frame size) had become so common, a 50mm lens (and other other lens for that matter) or other should produce this much picture. 50mm been generally has been viewed from this de-facto perspective. Hence why we get this crop factor as a result.

So regardless, the lens itself is still a XXmm lens, regardless of the sensor/media is it focused on. The crop factor only comes into play when it is compared to a different sensor/media and from that, it is just a crop of the picture. The focal length of the lens doesn't change. The crop factor is just expressed as an equivalent expressed in 35mm terms.

Just my thoughts.

[realart]

Here's my two cents worth on the topic:

The thing to remember, a 50mm lens is still a 50mm lens, regardless of the sensor/media type. The crop factor is not affecting the focal length which is what the 50mm is referring to.

In the past, since 35mm (or what became the de-facto full frame size) had become so common, a 50mm lens (and other other lens for that matter) or other should produce this much picture. 50mm been generally has been viewed from this de-facto perspective. Hence why we get this crop factor as a result.

So regardless, the lens itself is still a XXmm lens, regardless of the sensor/media is it focused on. The crop factor only comes into play when it is compared to a different sensor/media and from that, it is just a crop of the picture. The focal length of the lens doesn't change. The crop factor is just expressed as an equivalent expressed in 35mm terms.

Just my thoughts.

That is very true, but you need both pieces to really come up with anything useful. Take a 50mm lens on a Minox which uses 8mm x 11mm film. That 50mm lens would have the equivelant crop factor as a 192mm lens on a 35mm camera. On a 6x6 (2 1/4) camera the image would have the equivelant crop factor of around a 30mm lens on a 35mm camera. Now yes, the size of an object in the image will be the same regardless of the format. But I think a more overriding factor is, in fact, the crop factor. For example, in a portrait, how far one should be from the subject. Because of the crop factor to get an equivelant crop on, say, my D90 vs a 35mm film camera, I would have to be further from the subject as the 50 acts as a telephoto due to the crop. This gives me a more pleasing perpsective for facial features. Similarly I would not put a 50 on a Minox (extreme example I know but I think it is valid?) and expect to do use it as a "normal" lens but would as a decent telephoto. Again due to the crop factor.

So to me, I think the crop factor is the most important aspect in the discussion. Because it is the crop factor that dictates the composition when using the same FL on differing formats.

err -am I making sense? :blush2:

[Loupey]

Liz, you have a 25mm lens. You are using a 25mm on an Olympus EP-1.

I have a 50mm lens but I use it on both my Canon 5D and 50D - the lens is the same 50mm.

It's like the metric system. Think of a liter like a liter or a kilometer like a kilometer - easier than trying to convert it back and forth from gallons or miles. The "crop-factor" is a perpetual source of confusion.

[Frog]

I believe the purpose of the thread is to show what a versatile lens the inexpensive 50mm is.
The thread got me to buy one and I'm not disappointed.
Other lenses, no matter how wonderful, are not in such wide spread use.
I don't think it wise to start a thread for all the XXmm lenses.
There are plenty of places to post pics using other lenses.
Just my opinion.

[Loupey]

I believe the purpose of the thread is to show what a versatile lens the inexpensive 50mm is.

I agree completely. It is a discussion regarding the "50mm lens" - not every combination of lenses and bodies available to get to that "equivalent" 50mm IMO.

Especially since 90+% would be immediately disqualified as most people don't use full-frame digital bodies.

[xystren]

That is very true, but you need both pieces to really come up with anything useful. Take a 50mm lens on a Minox which uses 8mm x 11mm film. That 50mm lens would have the equivelant crop factor as a 192mm lens on a 35mm camera. On a 6x6 (2 1/4) camera the image would have the equivelant crop factor of around a 30mm lens on a 35mm camera. Now yes, the size of an object in the image will be the same regardless of the format. But I think a more overriding factor is, in fact, the crop factor. For example, in a portrait, how far one should be from the subject. Because of the crop factor to get an equivelant crop on, say, my D90 vs a 35mm film camera, I would have to be further from the subject as the 50 acts as a telephoto due to the crop. This gives me a more pleasing perpsective for facial features. Similarly I would not put a 50 on a Minox (extreme example I know but I think it is valid?) and expect to do use it as a "normal" lens but would as a decent telephoto. Again due to the crop factor.

So to me, I think the crop factor is the most important aspect in the discussion. Because it is the crop factor that dictates the composition when using the same FL on differing formats.

err -am I making sense? :blush2:

I can see where your coming from. It pretty much depends what your considering the important/defining part.

From a composition perspective, crop factor is fairly irrelevant if you are composing through the viewfinder. Crop factor is completely irrelevant if there is nothing else to compare it to. Crop factor only becomes a concern when there is comparison between two dissimilar pieces of equipment.

If we were talking cars, there would not be a question if Model A and B were both six-cylinder cars (aka focal length). But if we were talking in terms of horse power (aka crop factor), model A could be 200hp, where model B could be 250hp. There still wouldn't be the question if they were six-cylinder cars. So why when it comes to lens do we get so concerned about equivalents?

I suppose this is one of those debates that could go on forever. From one perspective, a APS-C sensor could have a 1.6x crop factor (assuming that FF has a 1 factor.) But, by the same argument, one could say that a FF sensor could have a 0.4x crop factor (assuming that a APS-C sensor has a 1 factor). I don't think there is a single right or wrong answer in this. I think for the purpose of the question of original post, my opinion is the XXmm focal length needs to be looked at in terms of the equipment being used. Not in terms of the equipment being compared differing equipment.

[Dave6223]

Liz,

To me a 50mm is a 50mm, regardless of the format. It's still a good old 2"er. My zuiko may well be a 100mm equivalent on digital, but it's still a 50mm. And a fast one at that.

[Old Timer]

Well your post sure has stimulated a good discussion Liz. But as far as my original thread goes it was meant to high light the 50mm f 1.8 lens. It is cheap and versatile little lens that many times gets over looked by those of us that want bigger and better. As some have said the 50mm is a 50mm regardless of what body you attach it to and that was what I was looking for in that thread.

[Franglais]

Frog's post sounds familiar.

I see the 50mm f1.8 thread as being an "anti kit lens thread". It's a message to all those people who bought a DSLR with a kit lens and got good results but who want to go further. It's saying that for minimum $$ you can get a lens which allows you to take pictures in low light, give you some wonderful restricted depth of field effects, with excellent image quality.

There used to be just one solution : the 50mm f1.8.

Liz is pointing out that now there are several solutions.

Correction: I just saw Old Timer's post. I hadn't thought of the bigger and better aspect

[Grandpaw]

Liz, to me I thought the intent of the thread was to show examples of what the 50mm 1.8 lens could produce. If we go by what you are suggesting in saying that your lens is equivalent to the 50mm because of the crop factor and can go in the thread and that was the real intent of the thread then the 99% that did use the 50mm on their digital really were shooting at 75mm with the crop factor and should not be there.

To me this is about a particular lens and examples of what it can do. Crop factors or cameras don't have anything to do with it. Liz, please post your pictures because they are always great and well worth looking at but I think this thread needs to be kept just about this particular lens, Jeff

[realart]

Liz, to me I thought the intent of the thread was to show examples of what the 50mm 1.8 lens could produce. If we go by what you are suggesting in saying that your lens is equivalent to the 50mm because of the crop factor and can go in the thread and that was the real intent of the thread then the 99% that did use the 50mm on their digital really were shooting at 75mm with the crop factor and should not be there.

To me this is about a particular lens and examples of what it can do. Crop factors or cameras don't have anything to do with it. Liz, please post your pictures because they are always great and well worth looking but I think this thread needs to be about the particular lens, Jeff

Say Jeff. Sometimes I am rather obtuse, but reading this I get it. It is simply a thread about "No matter what you have, what can your 50mm do?" You're right. It IS all about the lens. --phew--

[Dave6223]

I agree. Zuiko lenses are greatly underestimated and only appreciated by the people that have used them in my opinion.

Liz, post as many images as you have with the lens. I for one, look forward to seeing more of your work.

Dave

[Liz]

Well your post sure has stimulated a good discussion Liz. But as far as my original thread goes it was meant to high light the 50mm f 1.8 lens. It is cheap and versatile little lens that many times gets over looked by those of us that want bigger and better. As some have said the 50mm is a 50mm regardless of what body you attach it to and that was what I was looking for in that thread.

Wow! There are many wonderful and various responses here. I've enjoyed reading each one........I quoted OT's reply here because it sums up what many others have shared. The fact is that the original thread (created by OT) is meant for poster's to share their 50mm/f1.8 lens images - for all the reasons mentioned.

Thanks everyone for your input, comments and informative replies.

Liz

[Franglais]

An article in this morning's newspaper caught my eye - a French astronomer has just spent a year photographing the entire sky from different points in the globe using - a 50mm and a Nikon D3. He stitched the whole thing together to give a single rectangular image with all the Universe above our heads in 100 million pixels

The result is here. Sorry that it's all in French but the idea is that you use the slider to zoom in on the first image

http://sergebrunier.com/gallerie/pleinciel/

[Old Timer]

An article in this morning's newspaper caught my eye - a French astronomer has just spent a year photographing the entire sky from different points in the globe using - a 50mm and a Nikon D3. He stitched the whole thing together to give a single rectangular image with all the Universe above our heads in 100 million pixels

The result is here. Sorry that it's all in French but the idea is that you use the slider to zoom in on the first image

http://sergebrunier.com/gallerie/pleinciel/

Totally amazing. It just blows my mind to see something like that. Awesome site!!

[jetrim]

That 2 day time lapse video at the bottom of the page is awesome too!