What mirrorless lens (video) equates to a camcorder 20X optical zoom?

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Zendit_Outdoors Forum Member • Posts: 66
What mirrorless lens (video) equates to a camcorder 20X optical zoom?
1

What size (focal length) lens would a guy need on a mirrorless camera (say a Sony A7Siii) to be able to 'reach out' and film video at the same distance as a prosumer camcorder boasting a 20X optical zoom?

Real world scenario:

Say there's a elk standing 250 meters away in a meadow and your buddy has a camcorder with a 20X lens and you want to meet (or, preferably, beat!) the quality of his video, what focal length lens would you need? In other words, you want to elk to take up as much of the screen (assume the same image ratio is being used) as it will in your buddy's camcorder? Even better if you could get a little closer and clearer.

Thanks to any who reply.

Bob A L Veteran Member • Posts: 3,492
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?
5

Depends on  the actual field of view of the camcorder lens. Certainly no 20X zoom lenses available for the Sony mentioned.  The 20X on the camcorder only means that the telephoto focal length is 20 times the wide angle focal length. This does not tell you much of anything about the field of view at full telephoto without knowing the lens focal length and the sensor size of the camcorder.

FrancoD Forum Pro • Posts: 16,297
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?
1

This is where knowing the 35mm equivalent comes usefull.

For example the Panasonic HC X 1000 20 x 4.08 to 81.6 mm lens has the 35mm-equivalent focal range is 29.5-600mm at 17:9 aspect ratio, and 31-626mm at 16:9 aspect ratio.

Most camcorders will have that "equivalent" listed.

Mark Scott Abeln
Mark Scott Abeln Forum Pro • Posts: 18,137
Zoom ratio is not helpful
1

Zendit_Outdoors wrote:

What size (focal length) lens would a guy need on a mirrorless camera (say a Sony A7Siii) to be able to 'reach out' and film video at the same distance as a prosumer camcorder boasting a 20X optical zoom?

Find all of the zoom lenses available for your Sony. Divide the longest focal length by the shortest focal length and that gives you the zoom ratio. Whatever lens you find that beats 20x, then you'll win. However, this doesn't answer your question below.

Real world scenario:

Say there's a elk standing 250 meters away in a meadow and your buddy has a camcorder with a 20X lens and you want to meet (or, preferably, beat!) the quality of his video, what focal length lens would you need? In other words, you want to elk to take up as much of the screen (assume the same image ratio is being used) as it will in your buddy's camcorder? Even better if you could get a little closer and clearer.

The zoom ratio tells you nothing about either the longest or the shortest focal length, and hence it will tell you nothing about what angle of view you'll get on the elk at the longest focal length.

This formula should help:

Focal length / sensor width = subject distance / field of view at the subject.

This is the "law of similar triangles" from geometry.

If you know how far away the elk is, and if you know how tall the elk is, and if you know the size of your sensor, then you can algebraically determine what focal length you'll need. Whatever the zoom ratio of the lens you have, it must have a focal length that is somewhere within the zoom range.

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sybersitizen Forum Pro • Posts: 21,743
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?
2

Zendit_Outdoors wrote:

What size (focal length) lens would a guy need on a mirrorless camera (say a Sony A7Siii) to be able to 'reach out' and film video at the same distance as a prosumer camcorder boasting a 20X optical zoom?

Say there's a elk standing 250 meters away in a meadow and your buddy has a camcorder with a 20X lens and you want to meet (or, preferably, beat!) the quality of his video, what focal length lens would you need?

What's the maximum focal length of the camcorder lens? What's its aperture at maximum zoom? What's the size of its sensor? What's the sensor resolution? What's the final video resolution?

In other words, you want to elk to take up as much of the screen (assume the same image ratio is being used) as it will in your buddy's camcorder? Even better if you could get a little closer and clearer.

Realize that a 20x zoom is not required for the A7SIII to beat the camcorder in that contest. No zoom of any kind is required - just a lens with a particular focal length. Depending on the answers to those questions (and perhaps some others about lens quality and sensor generation), it might not even be necessary for the elk to 'take up as much of the screen' as it does in the camcorder in order for the A7SIII to 'meet or beat the quality' of the final video output.

john isaacs Veteran Member • Posts: 6,397
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?
4

Zendit_Outdoors wrote:

What size (focal length) lens would a guy need on a mirrorless camera (say a Sony A7Siii) to be able to 'reach out' and film video at the same distance as a prosumer camcorder boasting a 20X optical zoom?

Real world scenario:

Say there's a elk standing 250 meters away in a meadow and your buddy has a camcorder with a 20X lens and you want to meet (or, preferably, beat!) the quality of his video, what focal length lens would you need? In other words, you want to elk to take up as much of the screen (assume the same image ratio is being used) as it will in your buddy's camcorder? Even better if you could get a little closer and clearer.

Thanks to any who reply.

Let's take a Panasonic GH4 with a 14-140 f3.5-5.6 zoom lens. That's a 10x zoom on a 4/3 sensor (18mm x 13.5mm) with resolution of 4608 x 3456. It shoots 4k at 3840x2160.

In comparison, a Canon XA15 20x HD zoom camera has a native resolution of 1920x1080. That's half the resolution of the Pansonic 4k.

You can use digital teleconversion with the Panasonic, and essentially get 20x zoom to HD resolution.

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OP Zendit_Outdoors Forum Member • Posts: 66
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?

sybersitizen wrote:

Zendit_Outdoors wrote:

What size (focal length) lens would a guy need on a mirrorless camera (say a Sony A7Siii) to be able to 'reach out' and film video at the same distance as a prosumer camcorder boasting a 20X optical zoom?

Say there's a elk standing 250 meters away in a meadow and your buddy has a camcorder with a 20X lens and you want to meet (or, preferably, beat!) the quality of his video, what focal length lens would you need?

What's the maximum focal length of the camcorder lens? What's its aperture at maximum zoom? What's the size of its sensor? What's the sensor resolution? What's the final video resolution?

I’ll have to check those specs. I’m not filming currently so I don’t have a camcorder checked out. I’ll as one of the other guys

In other words, you want to elk to take up as much of the screen (assume the same image ratio is being used) as it will in your buddy's camcorder? Even better if you could get a little closer and clearer.

Realize that a 20x zoom is not required for the A7SIII to beat the camcorder in that contest. No zoom of any kind is required - just a lens with a particular focal length. Depending on the answers to those questions (and perhaps some others about lens quality and sensor generation), it might not even be necessary for the elk to 'take up as much of the screen' as it does in the camcorder in order for the A7SIII to 'meet or beat the quality' of the final video output.

A lot of this is over my head - the numbers and math makes my dyslexia flare up like shooting straight into the midday Sun! Lol. I think I’m sorta following… Since the A7Siii I’m STILL waiting on (stupid Sony + EPA related delays!) has such high resolution, particularly with a good lens with say a 200mm focal length, it’s possible to crop in in post and end up with an equally good (or possibly better) image than a camcorder - one that will fill the viewer’s screen in a similar way as what the camcorder provides. Is that an ugly and neanderthal understanding of what you’re getting at?

NickZ2016 Veteran Member • Posts: 3,600
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?

I don't know which camcorder you're asking about but for example the Sony AX53  claims an equivalent of 650mm 35mm format 4:3 don't ask me to explain how they figure that makes sense . It's too early to do the math and try and convert to 3:2.  In video 16:9 mode they claim 535.  Wide end is 28mm equivalent.

The problem is at those extreme focal lengths you really need a rock solid tripod.

With a 200mm FF lens you'd need to punch in more than 2x. If you started with an 8K video you would still end up below 4K.

The question becomes what are you hoping to end up with? In theory you could take a short 4K clip. Zoom in post. Then upscale it back to 4K. It might even blend with the non zoom to the point nobody notices.

 NickZ2016's gear list:NickZ2016's gear list
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OP Zendit_Outdoors Forum Member • Posts: 66
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?

NickZ2016 wrote:

I don't know which camcorder you're asking about but for example the Sony AX53 claims an equivalent of 650mm 35mm format 4:3 don't ask me to explain how they figure that makes sense . It's too early to do the math and try and convert to 3:2. In video 16:9 mode they claim 535. Wide end is 28mm equivalent.

The problem is at those extreme focal lengths you really need a rock solid tripod.

With a 200mm FF lens you'd need to punch in more than 2x. If you started with an 8K video you would still end up below 4K.

The question becomes what are you hoping to end up with? In theory you could take a short 4K clip. Zoom in post. Then upscale it back to 4K. It might even blend with the non zoom to the point nobody notices.

I’ll find out the specs on this year’s camera and get back to you. Kinda sounding like I just need to pick up a lens and shoot some footage to see what it looks like - all the figuring is clearly over my head. Lol. That’s the problem with just being a camera monkey with a camcorder all these years and letting the studio do everything else. 😥

NickZ2016 Veteran Member • Posts: 3,600
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?
1

Zendit_Outdoors wrote:

Kinda sounding like I just need to pick up a lens and shoot some footage to see what it looks like -

Always a good idea

 NickZ2016's gear list:NickZ2016's gear list
Nikon D800 Nikon AF-S Nikkor 50mm F1.4G Nikon AF Nikkor 35mm f/2D Nikon AF-S Nikkor 50mm F1.8G Nikon 85mm F1.8G +4 more
sybersitizen Forum Pro • Posts: 21,743
Re: What mirrorless lens (video) equates to a camcorder 20X optical zoom?

Zendit_Outdoors wrote:

sybersitizen wrote:

Zendit_Outdoors wrote:

What size (focal length) lens would a guy need on a mirrorless camera (say a Sony A7Siii) to be able to 'reach out' and film video at the same distance as a prosumer camcorder boasting a 20X optical zoom?

Say there's a elk standing 250 meters away in a meadow and your buddy has a camcorder with a 20X lens and you want to meet (or, preferably, beat!) the quality of his video, what focal length lens would you need?

What's the maximum focal length of the camcorder lens? What's its aperture at maximum zoom? What's the size of its sensor? What's the sensor resolution? What's the final video resolution?

I’ll have to check those specs. I’m not filming currently so I don’t have a camcorder checked out. I’ll as one of the other guys

In other words, you want to elk to take up as much of the screen (assume the same image ratio is being used) as it will in your buddy's camcorder? Even better if you could get a little closer and clearer.

Realize that a 20x zoom is not required for the A7SIII to beat the camcorder in that contest. No zoom of any kind is required - just a lens with a particular focal length. Depending on the answers to those questions (and perhaps some others about lens quality and sensor generation), it might not even be necessary for the elk to 'take up as much of the screen' as it does in the camcorder in order for the A7SIII to 'meet or beat the quality' of the final video output.

A lot of this is over my head - the numbers and math makes my dyslexia flare up like shooting straight into the midday Sun! Lol. I think I’m sorta following… Since the A7Siii I’m STILL waiting on (stupid Sony + EPA related delays!) has such high resolution, particularly with a good lens with say a 200mm focal length, it’s possible to crop in in post and end up with an equally good (or possibly better) image than a camcorder - one that will fill the viewer’s screen in a similar way as what the camcorder provides. Is that an ugly and neanderthal understanding of what you’re getting at?

It's part of what I'm getting at.

You asked what focal length is needed to meet or beat the quality of a camcorder video in a specific situation. An answer can be provided, but only if we first know what sort of quality the camcorder can produce. My questions are important for determining that.

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