Crop Senser Crises
Mar 12, 2016 21:02:52 #
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
Mar 12, 2016 21:05:17 #
Mar 12, 2016 21:09:48 #
alandg46 wrote:
Yes.
No...., but see my comment a few threads lower down, and those of others....
Mar 12, 2016 21:11:05 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
Yes.
The focal length of a lens isn't changed by the size of the sensor. What changes is the angle of view.
Mar 12, 2016 21:15:32 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
As has been said many, many times a 100mm lens is a 100mm lens regardless of what kind of sensor the camera uses. So the answer is Yes
Mar 12, 2016 21:16:07 #
to Alandg46. You say yes but what is the reasoning behind your answer. When the full frame lens casts an image onto the crop sensor it ony records the central portion of the image, resulting in the perceived increase in focal length. With a lens designed for a crop sensor body there is no loss of pixels when the image falls onto the cropped sensor. So, why should I multiply by a crop factor in that scenerio?
Mar 12, 2016 21:16:38 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
Yes to get the 35mm equivalent you need to multiply it by 1.5 for Nikon and 1.6 for Canon.
Review any DX lens at B&H or other site for confirmation.
Mar 12, 2016 21:19:35 #
bobsuruncle wrote:
to Alandg46. You say yes but what is the reasoning behind your answer. When the full frame lens casts an image onto the crop sensor it ony records the central portion of the image, resulting in the perceived increase in focal length. With a lens designed for a crop sensor body there is no loss of pixels when the image falls onto the cropped sensor. So, why should I multiply by a crop factor in that scenerio?
What does pixels have to do with anything?
Mar 12, 2016 21:20:26 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
Yes!
If you use a 14-42 lens on a micro4/3 sensor, with a crop of 2X, it behaves (AOV) at 28-84mm.
Mar 12, 2016 21:21:12 #
It's not the right way to think about it really. The lens stays the same, but the sensor the image is projected onto is smaller, so the effect of what you see is magnified and only captures a part of the image that a larger sensor would capture. It does however mean that the effect of any movement is also magnified which can increase the perception of blur.
It is probably better to think about it in terms of cropping an image, rather than the focal length of the lens.
However, although a 500mm lens is a 500mm lens, on a crop sensor camera it shares some of the characteristics and difficulty of use of an 800mm lens on a full frame body.
It is probably better to think about it in terms of cropping an image, rather than the focal length of the lens.
However, although a 500mm lens is a 500mm lens, on a crop sensor camera it shares some of the characteristics and difficulty of use of an 800mm lens on a full frame body.
Mar 12, 2016 21:22:24 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
Yes, but only as far as angle of view - depth of field, image magnification and perspective remain the same. A 100mm lens on a 1.5 crop sensor camera will have a field of view equivalent to a 150mm lens, but DoF image magnification and perspective will be the same.
If it is a lens designed for a crop camera, the image circle projected onto the sensor will be just big enough to cover the smaller sensor, and will appear as a circle on a full frame camera. If it is a lens that is designed for full frame, the image circle will be considerably larger than the small sensor, so in essence you are likely to have better image quality, since many lenses are better in the center than at the edges and corners.
Mar 12, 2016 21:22:38 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
Yes!
If you use a 14-42 lens on a micro4/3 sensor, with a crop of 2X, it behaves (AOV) at 28-84mm.
The focal length of the lens does not change... The Angle of view is delivered to appear like a 2 times focal length.
Mar 12, 2016 22:09:45 #
The answer is yes, as you stated it is a perceived new focal length. An FF or DX 100 mm lens is still a 100mm lens and would have the same effect.
As a photographer I am more interested that the outcome, my photograph, has the effect of shooting with a new focal length. The industry has standardized on that terminology and in last falls Digital Photography class at Harvard, the instructor acknowledged that although technically the common terminology is not precise, they will use it, as it has become the standard and there is no use trying to confuse people.
On the internet, typically there is a group that likes to buck the 'norm' to prove they are right. And they are right, but what they say doesn't help take a better picture.
--
As a photographer I am more interested that the outcome, my photograph, has the effect of shooting with a new focal length. The industry has standardized on that terminology and in last falls Digital Photography class at Harvard, the instructor acknowledged that although technically the common terminology is not precise, they will use it, as it has become the standard and there is no use trying to confuse people.
On the internet, typically there is a group that likes to buck the 'norm' to prove they are right. And they are right, but what they say doesn't help take a better picture.
--
Mar 12, 2016 22:18:52 #
Let take the example of the 35mm lens as Nikon makes both the FX and DX version in 35mm. An FX 35mm lens is capable of delivering an angle of view of 63 deg on an FX sensor. A DX camera can only use the center portion of the image and give an angle of view of 44 deg. The DX 35mm is capable of only 44 deg angle of view and it will give 44 deg on a DX camera and may be a little bit more than that (but much less than 63 deg) on an FX camera with the outer portion of the image dark.
Mar 13, 2016 06:26:19 #
bobsuruncle wrote:
Hello UH members. I understand that if you take a lens designed for a full frame body and put that lens on a crop sensor body you generally can multiply the focal length of the lens by the crop factor to achieve the new perceived focal length of the lens. In the case of a 100mm prime, the lens behaves like a 150mm lens on a crop body. My question is, if you have a lens specifically designed for a crop sensor body, do you even have to multiply that particular lens by the crop factor at all?
no they are designed to fit the dx sensor . I like to use full frame on dx bodies because you work just the sweet spot of the lens.
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.