10

Assuming that the quoted 1365mm focal length is in 35mm full frame equivalent terms (because otherwise, it would be huge), then the actual focal length of the lens assembly is around 1365 / 5.6 ~= 244mm. To accomplish an equivalent 1365mm focal length with a 1.6 crop factor, you would need about an 854mm actual focal length lens. I'm not aware of anything ...


7

In photography, what is interesting is mostly the angle of view (AOV). The AOV is the angle that a lens offers on a sensor - it can be specified horizontally, diagonally, or vertically. AOV [°] = 2 * arctan ( sensor_height|width|diagonale [mm] / (2 * focal_length [mm]) ) The formula to get from a specified focal length (FL) on a non-full-frame sensor to ...


6

Based on others' calculation that you would need approximately an 850mm lens - which is not going to really be in any normal person's budget, nor even really portable - see the humorous article The Question of 18-300mm Lenses, Part Deux to see how big [& expensive, $16,000] the Nikon 800mm is. The article compares it to the 18-300mm lens which ...


6

However, if I understand correctly the aperture need to be multiplied as well, which results in an f2.1 and means I am losing at least an f-stop. In short: No. If you use a FF-lens with an APS-C sensor, part of the light that is collected by the lens is not hitting the sensor but the amount of light that hits a part of the sensor stays the same (as long as ...


5

You will never lose any transmission stops (low light ability) using a smaller sensor, unless something behind the camera mount severely constrains what reaches the sensor (unlikely with general purpose still cameras one sensor size apart). Some would say ISO at different sensor sizes is not equivalent: When exposure is discussed, this is nonsense; such ...


5

By using an APS-C camera with higher pixel density, you will get "more pixels on the subject" than with a FF camera with lower pixel density. Sometimes that can be a good thing. There are many wildlife photographers who use APS-C cameras with telephoto lenses for this reason. It allows one to get more "reach" with shorter (and less expensive) lenses ...


4

Crop factor is a characteristic of the camera, not the lens. A 50mm lens is 50mm no matter what you attach it to. The bigger or smaller sensor is what leads to crop factor, which is the ratio of the area of a full frame sensor to the area of the sensor in question. Smaller sensors will have a ratio > 1, and medium format sensors (or other larger sensors) ...


3

Here is one way to think about this. Suppose we had a view camera (in simple terms - front and back rigid frames with removable boards connected with a bellows) that had three different backs - one for 35mm film, one for 120 film and one for 4x5 film - and was mounted on a sturdy tripod with a 90mm large format lens up front. Then we focus, get an exposure ...


3

The only reason that we even bother with this concept called "crop factor" is because of the absolute prevalence/dominance of 35mm film. Do you think the early shooters, big box view camera's in hand, were conceptualizing their lenses using a crop factor? The focal length of the lens, such as 50mm, is a characteristic of the lens. This is considered the "...


3

If an 85/1.4 lens is needed to accomplish a real photographic goal, and you're willing to spend the money, go for it. However, if you're just chasing a large aperture, it isn't worth the extra cost. An 85/1.4 lens on crop sensor is not "versatile": The field of view and working distance limit composition and subject selection. Often framing is too tight ...


3

I think you're over-thinking this, and with all respect to everyone else trying to help, I think the answers focusing on depth of field equivalence calculations are making things worse. No one is wrong — I just think it's leading in the wrong direction. Let me suggest a different approach. The crucial thing first: you will absolutely be able to make ...


2

I happen to have Canon 85mm f/1.8 (35mm equivalent 136mm) lens for use with my Canon 1.6x crop sensor camera. It's a bit long for being the most used lens, but it's definitely good for low-light conditions where a mild telephoto is needed. Before I had the 85mm f/1.8, I used a 50mm f/1.8 a lot and found many shots from long distances would have benefited ...


2

You have a lot of good answers already. Technically an 85mm lens is an 85mm lens regardless of camera body. The "crop factor" doesn't really change the focal length per se... it's just that on a crop-body you're only using a 28mm image circle instead of a 43mm image circle (specifically a 3:2 rectangle that can fit inside that circle). In other words, ...


2

Okay, so to boil it down, you're wondering if an 85 f/1.4 would be worth it on an APSC camera because of the crop factor. Comparatively speaking, your field of view will be equivalent to 127.5mm on a FF camera with DoF equivalent to f/2.1. So, comparatively speaking, if you were to ask a similar question, "Should I buy a 135mm f/2.0 for a FF camera?" ...


2

Camera math provides lots of equivalent ways to solve this optical problem. You know that your heart’s desire is a compact digital crop factor 1.6 (might be 1.5 depending on model). One approach is to find the inverse value of the crop factor and multiply. For a camera crop factor 1.6, the math is 1/1.6 = 0.625. For this format you would search for a 1365 x ...


2

If the goal is to use the same focal length lens and yield the same crop on FX (full frame) vs. DX (compact digital), the camera to subject distance is decreased with FX and increased with DX. Thus for this lash-up, the DX working from afar, delivers expanded DOF resulting in reduced background blur. Conversely, the FX, working in closer delivers contracted ...


2

Depth of Field is computed from focal length, aperture, focus distance, and also sensor size. The distance limit of the depth of field is where the blur circle diameter is computed to exceed the maximum acceptable Circle of Confusion, which is computed from sensor diagonal size. With all other factors equal: A shorter focal length has greater depth of ...


1

I'm going to chime in with a far less precise response (credit to the previous responders). You asked which setup would provide "more" bokeh. As I'm sure you know, bokeh in all its facets - the 'amount', the shape of the background objects (circular, angular etc) - is one of the most subject aspects of photography. It is so much more than blur. That ...


1

The Sigma 56mm f/1.4 would have the most background blur of the three, but the Sigma 30mm f/1.4 is very close because you need to move much closer for the same framing. The Minolta 50mm f/1.8 will have more depth of field, and not as much background blur as the other two. The type of lens or "native" mount does not matter. All that matters is the camera ...


1

You should realize that with the Same lens from the Same distance, the smaller sensor (called a cropped sensor) crops the field of view proportionately. So it is Not the same picture, its view is cropped. To see the same full field of view, the cropped sensor has to stand back more, to distance x crop factor. Depth of Field is greater if a shorter focal ...


1

The sensitivity/ quality of pixels/receptors is not dictated by whether the sensor is crop or full frame. It is dictated by complex technologies and manufacturing processes in the sensor. Although not according to the above comment! Either way - it's useful to think of it like this. In your case, the z6 sensor is more up-to-date with better tech, meaning ...


Only top voted, non community-wiki answers of a minimum length are eligible