Why focus to infinity

In live view, zoom in to your focus point to the maximum available, then move your focus point so that it is directly over the bright planet. Turn the manual focus ring until the planet or bright star is in precise pinpoint focus. It requires a very small movement of the focus ring and is very obvious when it is in focus. It will help if you zoom in on the bright planet or star in live view using live view zoom controls. Some very recent cameras can auto-focus on planets or bright stars.

I can only speak to the low-light capabilities of the new Nikon Z6 and Z7, but those two cameras do have a low-light AF mode that you can turn on. The focusing speed in low-light situations is not particularly fast, but it does work on bright planets. Once again, zoom in on the focus point and place the focus point on the planet.

Engage auto-focus and wait for a second or two and it should autofocus on the planet. Then turn your lens to manual focus. You snapped a photo of your focus ring at infinity focus like I described above, correct?

If so, pull up that snapshot and use your flashlight or headlamp to set the focus ring to that same spot. To make the process go faster, crank up your ISO setting as high as you can, say 12,, 25,, or higher. Take a photo, then zoom in as far as you can on the image and look at the size of the stars. You want them to be as small and sharp as possible, not soft blobs of light.

Make very minute changes to your focus ring, take another shot, and zoom in on focus again. This process can take a little time, but you can often nail focus with just a few test shots. If you are shooting during an extended period at night, be sure to periodically check your focus by zooming all the way in to your photos on the back screen of your camera to check the focus of the stars, in case you have bumped the focus ring of your lens.

Star photos can look awesome on the back screen of your camera when not zoomed in, but you may get home and be disappointed by your stars when you see the photos larger on your computer screen. Night photography can be tricky when first starting out, but is very rewarding when you get the hang of it. Keep practicing and the process will get easier every time.

Kevin Lisota March 13, Isn't it only when doing NON-infinity focusing that there is a depth of field difference between wide apertures and narrow apertures, whereas, when focusing to infinity, it would look identical either way I mean, other than how bright the image would be i guess, since a wider aperture would let in more light.

Do a google search. Don't have the link right now. There is no relation. Focus to infinity means you turn the focus ring of the lens until very, very far subjects are sharp. In the old days, when things were simpler, the lens would have a focus scale and a focus ring and the infinity mark was easily also optically infinity sharp. Nowadays for cheaper Auto Focus lenses, to save money and for other reasons, they don't have a focus scale - so you could turn the focus ring a bit past the infinity infinity mark.

In a related topic, some of us buy old alien lenses and fit them onto our camera bodies. In this case, since the lens was not made the for camera and there are different adapter thickness and body thickness, even if the lens has a focus scale, the scale is wrongly calibrated for our new camera.

In this case, we say "the old lens can focus for macros and up to 6 ft but can't focus to infinity". That is an unrelated topic. This is about landscape photography. Landscape scenes vary. Some of them have a lot of ground - grass texture, earth texture.

Some of this grass texture, earth texture, shrubs and trees may be at 6 ft. Consult your DOF chart or calculator. And also use your eyes on inspecting the photo. That's the real test. There is no right or wrong - there are just instances of individuality and individual choice. That last bit optically infinity sharp doesn't make any sense. There is no way to get infinitely sharp and I'd presume you'd know this so what were you trying to say?

You do have to wonder how much money they actually save not printing the distance and hyperfocal charts we used to get on lenses. A few pennies probably. OK, so I have a related infinity focus question that arose when I was trying my own shot at a supermoon pic. I was using a canon 7D with a canon mm prime and a canon 2x converter on a tripod using a 10 second timer.

I also found that my pics weren't as sharp as I'd like. But my immediate question is: how come my focus point was less than infinity? I figure the moon is as far away as any object I'd expect to shoot! To be clear, using the gear above, I set the lens to manual focus, and was mostly trying out f-stops ranging from f9 tp f11 while varying the shutter speed to vary the light.

But pictures set to focus on infinity were totally out of focus. Instead, I had to fiddle and adjust focus at less than infinity. How is this possible? Is the 2x converter messing things up? Doesn't make sense to me. Infinity focus is the condition when the light from the same point is following a parallel course, and that light can be focused to a point.

The first drawing is how things work normally. In the second drawing the light is also coming from a single point…but because the point is infinitely far away the light rays are parallel. Infinity focus dictates a certain distance from the lens to the focal plane the sensor. How did you "set the focus on infinity"?

If you were just turning the focusing ring until it lined up with an infinity mark, or cranking the ring until it stopped, you weren't accurately focusing on infinity. Even a tiny difference in setting will affect the actual plane of focus, so you can't rely on marks on the lens. Worse yet, many lenses are designed to focus beyond infinity there's a concept! The best way to focus on the moon is to use live view, with the LCD image magnified 5x or 10x if you camera provides that, which the 7D does , and focus manually until you find the optimum point.

You then don't need to worry about whether it is "infinity" or not; it is in focus! I've seen a few mentions of manual focus for moon shots? Is auto not supposed to work? Seemed fine when I used it. Autofocus can certainly work, especially if you can use spot-type focus points. But since the moon is the single object you want to focus on, and it doesn't move very fast it is usually more reliable to use magnified live view, where you are working with the sensor image itself, and your own eyes to tell you what is in focus.

It's confusing for the newbie when the internet is full of articles that assume some level of background knowledge or context. And newbies then try to read between the lines and add their own context and the whole thing becomes a misunderstood mess. Lens adapters not being able to focus to infinity is a specific case and should not be used to generalise rules about photography.

This specific case arises when a particular brand, let us call it Minolta MD manual focus mount was deprecated by Minolta in favour their auto focus new bodies and lenses let us call this the Sony Alpha E mount.

In so doing, they had to tell owners of previous equipment "sorry, your lenses won't focus on our new bodies anymore because we had to make our bodies thicker with a longer lens flange distance".

Third party adapters were made and lo and behold, the lens could fit and be used for near distance but if the subject was far, no matter how much you rotated the focus ring, the image would not reach focus - hence the phrase - "you can't focus to infinity".

Kit lenses for modern cameras are a severe cost saving. The focus ring on Canon, Nikon and I think Pentax is so thin and the lens is so small, there is no place to print any marks. The lenses may not even focus at infinity if you turn the focus ring full - that may be lens design. These kit lenses are really meant for the auto focus system of the camera, not manual focus specifically although everyone does try at some time. Some brands, clockwise, some brands anti.

That can and does happen to modern AF lenses when you manual focus. However, there are a couple of instances where most photographers will turn to infinity focus.

First is the landscape. Wildlife photography is another good reason to use infinity focus. Finally, there is low light and nighttime photography. Just like narrow depth of field or creative lighting, infinity focus is one of those essential techniques that no photographer can do without. Will has been creating photographs and exploring his surroundings through his lens since He is a husband of twenty-eight years, father of four children, and has one grandchild.

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