Angle of view question: Please correct me if I'm wrong. My understanding is that if I mount a 100 mm DX lens on my DX camera (D7200) it will give me an angle of view equal to that of a...

rikhar Loc: Ct. shoreline

Please correct me if I'm wrong. My understanding is that if I mount a 100 mm DX lens on my DX camera (D7200) it will give me an angle of view equal to that of a 150mm lens because of the 1.5 crop factor. My question is this. If I now mount a 100mm FX lens on the same DX camera, will I still get a 150mm angle of view? In other words, does the dx/fx designation on a lens make a difference in the angle of view or is it just the size of the sensor that controls this. I'm sorry if this has already been answered but I couldn't find it in the search. Thank you in advance of your answer/answers

Rick

Kozan Loc: Trenton Tennessee

rikhar wrote:

Please correct me if I'm wrong. My understanding i... (show quote)

The angle of view will change because the image will be wider with an FX lens on an FX body.

kmpankopf Loc: Mid-Michigan; SW Pennsylvania

Unless it is a typo, if you mount a DX lens on a DX camera, you get the mm - a DX 100 mm on D7200 is still 100 mm. If you mount a FX lens on a DX camera, you get the increased angle. So a 50 mm FX lens on the D7200 will result in a 75 mm angle. And most software, like Bridge, will calculate it for you.

robertjerl Loc: Corona, California

rikhar wrote:

Please correct me if I'm wrong. My understanding i... (show quote)

A 1.5 crop factor is a 1.5 crop factor and a 100 mm lens is a 100 mm lens so they will both have the angle of view of a 150 mm lens on a DX body.

The difference is that if the DX lens is put on an FX body it won't fill the entire sensor because it is designed to fill a DX sensor. The FX lens will fill both size sensors bit the DX sensor will only see the center of the image circle from the FX lens.

CHG_CANON Loc: the Windy City

The lens focal length applies to the lens. That doesn't change whether the lens is FX or DX, 100mm is 100mm on either lens style.

The crop factor applies to any lens mounted to the DX format body. The crop factor is another way of saying the 'equivalent field of view'.

Where it gets confusing is when you consider the image circle produced by the DX-style lense (or Canon's EF-S). The DX lens sits closer to the sensor and produces a smaller circle that matches to the smaller DX sensor size. But, the lens is still 100mm.

When the images from the DX camera are compared to the reference full-frame lenses, the equivalent field of view still demonstrates the 1.5x crop of the DX-sized sensor, or said otherwise, the DX images present the equivalent field of view of a 150mm full-frame lens. Both the 100mm FX lens and 100 DX lens on a DX body will both produce images that 'look like' a 150mm lens on an FX body.

JohnR Loc: The Gates of Hell

kmpankopf wrote:

Unless it is a typo, if you mount a DX lens on a DX camera, you get the mm - a DX 100 mm on D7200 is still 100 mm. If you mount a FX lens on a DX camera, you get the increased angle. So a 50 mm FX lens on the D7200 will result in a 75 mm angle. And most software, like Bridge, will calculate it for you.

A 100mm lens is a 100mm lens is a 100mm lens is a 100mm lens ad infinitum. The angle of view does NOT change in any way. The size of the circle projected by the lens at the focal length changes according to the diameter of the lens. Bigger FX lens gives a bigger circle than a DX lens which gives a bigger circle than an M4/3 lens and so on. Using an FX lens on a DX camera results in a smaller part of the circle being recorded than were it an FX camera.

bsprague Loc: Lacey, WA, USA

I was at Yellowstone with my m43 camera pointed at a wolf. It had a 100-400 mm lens. The woman next to me and a full frame Nikon and a lens the length of my arm. She felt sorry for me with such a tiny camera and lens so offered me a peek at the wolf in her camera. I looked, smiled and thanked her because I had never looked through a lens that big. Size does matter! A few minutes later the wolf moved. I was shooting 4K video so the "crop factor", "angle of view" or whatever is different again. I offered her a look in my viewfinder. She was pissed because my viewfinder had more wolf in it than hers. I didn't even try to explain crop factors or equivalent views.

After the wolf left, we packed up. She had a large man to help carry her gear to her Suburban. In the back was a false floor. Beneath it was custom cut, foam lined compartments for he "wildlife" kit". Mine when into my camera bag.

If there is a point, mine would be to stop calculating and look through the camera and lens. If it is working, use it. If not get a bigger or smaller lens.

PHRubin Loc: Nashville TN USA

rikhar wrote:

Please correct me if I'm wrong. My understanding i... (show quote)

Any 100mm lens on a Nikon crop camera will give the angle of view of a 150mm lens as it would on a full frame camera. The label FX and DX indicate the size of the image projected on a sensor, the DX lens having a smaller image will not fill an FX sensor. An FX lens projects a larger image that can fill either type sensor.

Alans844

rikhar wrote:

... If I now mount a 100mm FX lens on the same DX camera, will I still get a 150mm angle of view? ...

Rick

Rick, yes, 150mm angle of view in either case. I read the other posts and taken together I almost got a headache. Hope this helps.

joer Loc: Colorado/Illinois

rikhar wrote:

Please correct me if I'm wrong. My understanding i... (show quote)

In both cases you will get 150mm AOV assuming its not a Canon.

The DX/FX lenses produce different image circles...DX lens won't cover a FF sensor completely. The sensor size also controls this, a crop sensor can not record the full image circle of a FX lens, with limited exceptions. So they both have an impact depending on the camera and lens involved.

Some DX zoom lens have sufficient image circles to cover a FF sensor but only at some focal lengths.

Your best option is don't mix and match if there is a choice.

BebuLamar

rikhar wrote:

Please correct me if I'm wrong. My understanding i... (show quote)

The 100mm FX lens on an FX camera gives you a diagonal angle of view of 24.4°. Either an FX or a DX lens of 100mm would give you 16.1° diagonal angle of view on a DX camera.
Now if you mount a 100mm DX lens on an FX camera you would get at least 16.1° angle of view of good image in the center of the frame. Outside that you may get severe vignetting.

PHRubin Loc: Nashville TN USA

joer wrote:

Your best option is don't mix and match if there is a choice.

There is nothing wrong with using FX lenses on a DX camera, but there is definitely something lost when using a DX lens on an FX body, if it will even mount (Canon EF-S lenses won't mount on FF bodies).

MT Shooter Loc: Montana

kmpankopf wrote:

Unless it is a typo, if you mount a DX lens on a DX camera, you get the mm - a DX 100 mm on D7200 is still 100 mm. If you mount a FX lens on a DX camera, you get the increased angle. So a 50 mm FX lens on the D7200 will result in a 75 mm angle. And most software, like Bridge, will calculate it for you.

Absolutely incorrect. 100mm is ALWAYS 100mm no matter what camera it's on. What changes is the image captured by the sensor that the lens projects its image on. With an APS-C that "crop factor" is 1.5x for all cameras except Canon, which has a crop factor if 1.6x due to its physically smaller APS-C format. This crop factor applies to ANY AND ALL LENSES MOUNTED ON THAT SMALLER SENSOR. Period.

Delderby Loc: Derby UK

This is how I see it.
A 100mm DSLR lens on a DSLR camera will have a tighter field of view than a 100mm FF lens on a FF camera. Therefore the image from the DSLR will fill the frame with a lesser view than that of the FF. i.e. less than the whole mountain with the DSLR, all of the mountain with the FF. Therefore it appears that the DSLR lens has a longer reach (which it does not). It follows that if the FF image is cropped down to show the same view as that from the DSLR, with everything else being equal, including the sensor mpxs, the FF pic will have more detail than the DSLR (granted - you may not see it). QED

bpulv Loc: Buena Park, CA

rikhar wrote:

Please correct me if I'm wrong. My understanding i... (show quote)

If you mount a 100mm DX lens on a DX camera, your angle of view will be that of the DX lens (100mm AoV) because the circular image projected by the DX lens will be just a little larger than that of the size of the sensor. If you mount a 100mm FX lens on a DX camera, there will be a 1.5 crop factor (150mm AoV) because the circular image projected by the FX lens is larger than that of an DX lens. The lens will still be a 100mm lens, but you will be using a smaller portion of its image. Note that you do not end up with a 150mm lens with 150mm lens properties. You end up with a cropped 100mm lens image.