EF-S 18-135mm f/3.5-5.6 IS STM - Best Way To Set Focus on Infinity?

[wchettel]

I am using a Canon EOS Rebel SL2 with a Canon EF-S18-135mm f3.5-5.6 IS STM lens. Is there an easy way to set the focus on infinity when I'm using MF mode on the lens? I just want to set it and forget it.

[Ray-uk]

I assume you are using it for astro-photography, if so then set your focus using the moon.

In normal photo conditions just focus on something as far distant as you can find, although I don't understand why you would want your focus fixed on infinity for everyday photo situations.

[Waddizzle]

Look into what lens bands do. They are big rubber bands that go on a lens to prevent zoom ring creeping. I guess they could lock a focus ring down, too.

Be aware that focus may drift as temperature changes. I think it is best to focus on a bright star, instead of the Moon.

[RobertTheFat]

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@Waddizzle wrote:
Look into what lens bands do. They are big rubber bands that go on a lens to prevent zoom ring creeping. I guess they could lock a focus ring down, too.

Be aware that focus may drift as temperature changes. I think it is best to focus on a bright star, instead of the Moon.

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I would think that a point source with a tendency to flicker ("Twinkle, twinkle, little star ...") would be harder to focus on than the Moon.

[wchettel]

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@Ray-uk wrote:

I assume you are using it for astro-photography, if so then set your focus using the moon.

In normal photo conditions just focus on something as far distant as you can find, although I don't understand why you would want your focus fixed on infinity for everyday photo situations.

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Ray-uk, It's not for everyday photo situations. I live just off the flight path of Fort Lauderdale-Hollywood International Airport. A few times each day there's a flood of planes either landing or taking off. I'd just like to take some pics of the planes without worrying about the focus.

And, I occasionally like to take pics of the moon and stars but I usually do that using a tripod and remote control using the app on my phone.

[RobertTheFat]

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@wchettel wrote:

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@Ray-uk wrote:

I assume you are using it for astro-photography, if so then set your focus using the moon.

In normal photo conditions just focus on something as far distant as you can find, although I don't understand why you would want your focus fixed on infinity for everyday photo situations.

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Ray-uk, It's not for everyday photo situations. I live just off the flight path of Fort Lauderdale-Hollywood International Airport. A few times each day there's a flood of planes either landing or taking off. I'd just like to take some pics of the planes without worrying about the focus. ...

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Well, that's what autofocus is tor, isn't it? I would think that your camera, like other recent Canon DSLRs, must have at least one motion-sensitive AF mode that would suit your purpose.

[Waddizzle]

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@RobertTheFat wrote:

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@Waddizzle wrote:
Look into what lens bands do. They are big rubber bands that go on a lens to prevent zoom ring creeping. I guess they could lock a focus ring down, too.

Be aware that focus may drift as temperature changes. I think it is best to focus on a bright star, instead of the Moon.

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I would think that a point source with a tendency to flicker ("Twinkle, twinkle, little star ...") would be harder to focus on than the Moon.

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I agree.  It would probably be easier to focus on the Moon than a bright star.  But, that's the whole point.  Besides, if I were photographing images of the night sky, I don't think I would be doing so on a night with the Moon in the sky.

[Waddizzle]

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@wchettel wrote:

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And, I occasionally like to take pics of the moon and stars but I usually do that using a tripod and remote control using the app on my phone.

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Different types of light sources can focus in different ways.

Notice the red dot on the focus ring next to the vertical white line on the focus ring?  Both are infinity focus marks.

[kvbarkley]

Uh, no. The red dot is the infrared focus mark. RTFM.

[ebiggs1]

"Uh, no. The red dot is the infrared focus mark."

It may take more than 10K for some folks.