Nikon 200-500mm and beyond infinity.

[RayP]

No, the title doesn’t refer to Buzz Lightyear.

The focusing ring on the 200-500 has a marker for infinity. But frustratingly, it allows movement beyond that setting. To try and ensure it stayed on infinity for this week’s solar eclipse I used some blu-tac to keep it from moving.

Sadly it moved slightly unknown to me resulting in a couple of shots being spoilt. This is one of my successful ones. Has anyone any suggestions on how to prevent it happening again? Why doesn’t the ring stop at infinity?

 

[Clovishound]

For one thing, on a zoom lens infinity focus may change as the focal length changes. On primes it's probably a cost thing, as each lens would have to be calibrated for focus ring stop, and likely have some extra machining to allow adjustment. This normally only becomes a factor when focusing in very low light. The moon should not be a problem focusing to. It's bright enough to see, and has a clearly defined border. AF may not handle it, but manual focus should be fairly easy. If you are doing something like milky way images, often you can focus on a tower light, unless you are in the middle of nowhere. A distant tower is close enough to infinity to work just fine.

 

[RayP]

It’s not a prime lens of course. I don’t anticipate focusing on the moon would be a problem but extended to 500mm the focusing becomes extremely critical. Set exactly on infinity the image is sharp. A little further either way and focus is lost.

I used a tripod and LV mode. So the camera had to be high enough for me to see the image on the rear screen. That made looking at the top of the lens difficult despite my height. I relied on manual focusing because the image wasn’t particularly bright. It’s a very dense filter.

This is a completely different situation to photographing the night sky.

 

[BF Hammer]

I have solar filters and photographed 2 eclipses. My mistakes in 2017 generated lessons for 2024.

Knowing there was just 1 shot to get right, I practiced. I got pretty good just photographing the sun and it's sunspots. A camera with a tilting rear screen really is a great aide for astro work. You can also tether to a PC with a USB cable to allow better micro-focus on a large screen. But my big lesson was to use the sunspots before the eclipse starts as something to focus on. Zoom the Liveview in and really work to bring sharp. Then apply a strip of duct tape to hold that focus in place and take another test shot.

And most lenses do not put a hard stop at infinity exactly. You get a little bit of room to dial it in right.

 

[RayP]

Then apply a strip of duct tape to hold that focus in place and take another test shot.

That’s what I did but used Blu-tac - a rubberised gel with good adhesive properties.

My D7100 doesn’t have a fold down screen. Hence why I used LV. But it’s a battery eater. More blu-tac should do the job.

 

[benhasajeep]

No, the title doesn’t refer to Buzz Lightyear.

The focusing ring on the 200-500 has a marker for infinity. But frustratingly, it allows movement beyond that setting. To try and ensure it stayed on infinity for this week’s solar eclipse I used some blu-tac to keep it from moving.

Sadly it moved slightly unknown to me resulting in a couple of shots being spoilt. This is one of my successful ones. Has anyone any suggestions on how to prevent it happening again? Why doesn’t the ring stop at infinity?

I have an older MF Tokina 300 f/2.8 MF lens. Great glass but over the years the focus ring is too easy to move. I solved that by taking a thick (wide) rubber band and you put it half on the focus ring, and half on the lens barrel. If you focus a lot it will tend to end up on one or the other half. But just move it back when it becomes less effective. No tape residue or anything like that is left on the lens. If one is not enough, use 2 or 3? P.s - if you can't find a band tight enough tie a knot in one too big to get more stretch / holding power.