conradyiu
closer
I recently joined the Fuji system with x-e1 and the kit lens.
I used R-D1 with LTM lens and understood that there is crop factor as the sensor is aps-c size but lens is designed for 35mm format. However, as the Fuji lens should be designed and made for aps-c sensor, I think there should be no crop factor on the x-e1. If so, why their lens still used the 35mm format focal length and we need to convert it by timsing 1.5? Eg., the 23/1.4 why not being named as 35/1.4 directly?
I'm sure I am wrong and just would like to know why?
I used R-D1 with LTM lens and understood that there is crop factor as the sensor is aps-c size but lens is designed for 35mm format. However, as the Fuji lens should be designed and made for aps-c sensor, I think there should be no crop factor on the x-e1. If so, why their lens still used the 35mm format focal length and we need to convert it by timsing 1.5? Eg., the 23/1.4 why not being named as 35/1.4 directly?
I'm sure I am wrong and just would like to know why?
Fraser
Well-known
probably because that would be even more confusing as the "23" is the focal length of the lens which never changes no matter the crop factor, and also the lens still has the perspective of a 23mm not a 35mm.
cidereye
Film Freak
End of the day a 23mm lens will ALWAYS be just that, a 23mm lens. Crop factor & sensor size is a different thing altogether.
I mean, on a Ricoh GRD for instance it's a 6mm lens but equates to 28mm in 35mm format.
I mean, on a Ricoh GRD for instance it's a 6mm lens but equates to 28mm in 35mm format.
craygc
Well-known
Hmmm... Given the 23mm on APS-C has the same AoV as a 35mm on full frame, one would assume that a user would stand at the same distance from the subject with both systems/lens. As such, the perspective would be identical for both lenses.
_goodtimez
Well-known
When Leica issued their M8 the film gate distance was the same as any other film Leica. What differed was the size of the sensor, in fact 1.33 times smaller than the size of 35mm film.
Everyone tended to state that with the M8 a Leica 28 mm became a 35 mm. This was wrong.
In fact, the perspective of the 28 mm remained exactly the same as with any film Leica, but what changed was that the overall angle of view was narrower, in this case the same angle as the one of a 35 mm. With the M8 this resulted like taking a Leica film picture made with a 28mm and cutting the edges until it reached the size of a picture made with a 35 mm.
So 2 things shall be considered when comparing a film camera to a digital camera today:
1) The size of the sensor.
2) The film gate distance.
Everyone tended to state that with the M8 a Leica 28 mm became a 35 mm. This was wrong.
In fact, the perspective of the 28 mm remained exactly the same as with any film Leica, but what changed was that the overall angle of view was narrower, in this case the same angle as the one of a 35 mm. With the M8 this resulted like taking a Leica film picture made with a 28mm and cutting the edges until it reached the size of a picture made with a 35 mm.
So 2 things shall be considered when comparing a film camera to a digital camera today:
1) The size of the sensor.
2) The film gate distance.
Paul Jenkin
Well-known
For me, it's what the end result (i.e. the photo) looks like and not the focal length, angle of view or the crop factor. I always "try before I buy" and do plenty of research. As a result, I don't get myself into a position where I regret what I bought and start wishing my camera offered something it doesn't and it can't.
I have an XPro-1 / 18mm / 35mm combo and love it. If I'd wanted a FF camera I would have bought something else.
I have an XPro-1 / 18mm / 35mm combo and love it. If I'd wanted a FF camera I would have bought something else.
craygc
Well-known
Perspective has nothing to do with focal length or AoV. The only parameter that affects perspective is the distance to the subject. If a 23mm or a 28mm lens has the same AoV as a full frame 35mm due to sensor cropping, a user is going to, in all likelihood, be positioned at the same distance from a subject for the same AoV. Therefore the 23mm (1.5x crop), 28mm (1.33 crop) and 35mm (FF) lenses would all demonstrate the same perspective.
Godfrey
somewhat colored
Focal length is an inherent property of a lens, not dependent upon format size or the resulting angle of view. It is the combination of a focal length used with a particular format that results in an angle of view. It would not be sensible or correct to rename a lens to be a focal length other what it is.
The reason people continue to apply crop factor calculations is because they have become accustomed to thinking of angle of view in '35mm film camera lens focal length' terms. It's a convenient (if often confusing) shorthand.
G
Aristophanes
Well-known
Older photographers have. Not many younger ones where 135 is foreign, like measuring weight in stone.
Roger Hicks
Veteran
35mm is an extreme wide angle on 6x9 cm and won't cover 4x5 inch at all: a 47mm is hard pressed. A "standard" lens on my 12x15 inch Gandolfi would be around 500mm. The "standard" on a classic Minox is 15mm. Everything depends on format. Giving "equivalents" is meaningless. Learn the diagonal of the format (the best definition of "standard", even if it is imperfect) and relate other focal lengths to that.
Cheers,
R.
Cheers,
R.
conradyiu
closer
Thanks a lot for so much information, so there is no images being cropped by the XF lens on the X-E1, right?
nongfuspring
Well-known
Well, with a few unusual exceptions the image circle on any camera is cropped by a rectangle/square, otherwise you'd be shooting circular photos surrounded by black.
Someone did an experiment to see wether or not the 35mm 1.4's image circle would cover the area of a 35mm sensor and it didn't. I imagine the case is the same for most if not all of the XF lenses.
charjohncarter
Veteran
Do you sometime wonder if WE are the only ones that think about these (which I do) things. Some of my friends have interchangeable lens digital cameras, some mention the 'crop factor.' But the only ones that really do are 35mm film photographers that have changed to digital. Maybe it is as Shakespeare said, 'Much Ado About Nothing.'
rluka
Established
The only APS-C sensor interchangeable lens camera I remember using the equivalent focal length would be the Ricoh GXR's APS units. 50mm, 28mm and 24-85mm.
But the lens is fixed to the sensor.
I imagine with camera that can use both APS and 35mm lenses (such as Canon and Nikon DSLR), stating the 35 equiv only will give headache to the support staff when customer came with confusion of why their 50 mm and "50 mm" lenses showed different view.
For the layman, it's easier for them when comparing lenses for different format.
For those who understand the technical side, it's the correct number.
Win-win
But the lens is fixed to the sensor.
I imagine with camera that can use both APS and 35mm lenses (such as Canon and Nikon DSLR), stating the 35 equiv only will give headache to the support staff when customer came with confusion of why their 50 mm and "50 mm" lenses showed different view.
For the layman, it's easier for them when comparing lenses for different format.
For those who understand the technical side, it's the correct number.
Win-win
JoeV
Thin Air, Bright Sun
Okay, hows about this: instead of using the term "crop factor," both the Fuji 23mm lens on its system camera body and the 35mm lens on its film body are 54 degree horizontal-angle-of-view lenses (1). We'll create the term "DHAOV" as an acronym. So, they're both 54 DHAOV lenses.
There; that sounds easier, no?
~Joe
(1) Assuming this approximation for a 35mm focal length lens: 2*Tan-1(18/35), based on the HAOV for a pinhole that's 35mm in front of a 36mm wide film frame. In practice, actual multi-element lenses will vary in their HAOV slightly, based on lens design, so in our new standard we'll use pinhole optics as the reference.
To find the pinhole-equivalent HAOV for any lens, use: 2*Tan-1(18/X), where X is the focal length as used on a 135-format film frame.
There; that sounds easier, no?
~Joe
(1) Assuming this approximation for a 35mm focal length lens: 2*Tan-1(18/35), based on the HAOV for a pinhole that's 35mm in front of a 36mm wide film frame. In practice, actual multi-element lenses will vary in their HAOV slightly, based on lens design, so in our new standard we'll use pinhole optics as the reference.
To find the pinhole-equivalent HAOV for any lens, use: 2*Tan-1(18/X), where X is the focal length as used on a 135-format film frame.
Godfrey
somewhat colored
Indeed true.
I think in terms of normal, wide, portrait tele, ultra-wide, tele, and long tele, for whatever format. Once I know the normal, the rest is easy. For example,
Oly E-M1: normal is 25, so 15, 45, 12, 75, 150 mm fills out the rest.
Sony A7: normal is 50, so 28, 90, 20, 180, 300 mm.
Hassy 500CM: normal is 80, so 50, 150, 38, 250, — mm.
Plus or minus, of course.
G
romi.gilles
i'm a wanderer
what ever focal length a lens is, it remains that focal length even when you're multiploying by a crop factor, period. focal length and fov are two different things. and don't forget to multiply the f-stop by the crop factor as well.
craygc
Well-known
No, the f-stop is the f-stop. Its value is a function of lens parameters only. What you are probably confused with is that for a comparison of same size prints from same AoV lenses across different sensor formats, your respective DoF appearance - in the magnified view only - will vary as if the f-stop were multiplied by the crop factor.
Lss
Well-known
I have met kids who have never used a film camera in their life and still discuss crop factors. If there is a division it is more likely between people who do not understand technology and people who at least try to.
willie_901
Veteran
When the focal lengths of lenses designed for 135 format film and 24 x 36 mm sensors is divided by ~ 1.5 one obtains a focal length for the Fujinon lenses that give a similar angle of view.
The angle-of-view for the Fujinon's is not cropped compared to lenses designed for the larger media area as long as the focal lengths differ by a factor or 1.5.
Just think about angle of view first and focal length second/sensor area second.
The angle-of-view for the Fujinon's is not cropped compared to lenses designed for the larger media area as long as the focal lengths differ by a factor or 1.5.
Just think about angle of view first and focal length second/sensor area second.