Nodal Rail

amfoto

amfoto

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Alastair
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Thinking of dipping my toes into a bit of panoramic photography. Ive done the lens on camera on table and pull back and measure. Only issue is lens I planned on using is my Nikon 24-70mm and when I measure the distance its 240mm from where I can just miss table.

Am I barking up the wrong tree, with trying to use the 24-70mm lens. Or do I really need a 50mm prime to make it work ( I don't have a nifty fifty )
 
I'd like to help, but I'm afraid I have no idea what this means:
amfoto said:
Ive done the lens on camera on table and pull back and measure. Only issue is lens I planned on using is my Nikon 24-70mm and when I measure the distance its 240mm from where I can just miss table.
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Can you explain a bit more slowly, please?
 
I'm with Stewart I'm afraid!

However, there's nothing wrong with using a 24-70 for panormas, and you only need a nodal rail when the subject includes close-distance objects, like interiors maybe. For most landscapes, it's just not necessary - what you want is a top-panning tripod head so you can set up quickly and easily and pan dead flat.

If you do need nodal rail, it needs to be long enough so the lens pivots around the entrance pupil (not the nodal point, that's a misnomer). That point will be a couple of cms behind the front element, and will move around a bit as the lens zooms. Google how to find the right spot, it's very easy and doesn't involve pulling back any tables that I'm aware ;) but you do need a nodal rail first.

Arca-Swiss type bits are best for this kind of thing (combined with an Arca-Swiss type tripod head) and you can put together a nodal rail very cheaply by just bolting a clamp to a suitable rail - about £25 all-in on Amazon/ebay.
 
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I much prefer a prime lens for nodal slide panos.

I think you will find that at longer focal lengths with the subject further from the lens the slide makes no difference with decent stitching software.

Where it does help is with wide focal lengths and close foreground objects by eliminating the parralax.

I think what you are saying is the the 24-70 changes length as it zooms. What camera are you using it on? Bear in mind the point you want pivoting around the centre of the ballhead is the entrance pupil of the lens not the physical front of the lens so that will help in what you can get away with.

I recommend you buy a neewer 200mm one and experiment with that as they are not expensive.
 
Craig_85 said:
I much prefer a prime lens for nodal slide panos.

I think you will find that at longer focal lengths with the subject further from the lens the slide makes no difference with decent stitching software.

Where it does help is with wide focal lengths and close foreground objects by eliminating the parralax.

I think what you are saying is the the 24-70 changes length as it zooms. What camera are you using it on? Bear in mind the point you want pivoting around the centre of the ballhead is the entrance pupil of the lens not the physical front of the lens so that will help in what you can get away with.

I recommend you buy a neewer 200mm one and experiment with that as they are not expensive.
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I was looking at the neewer 200mm . Thou when I measure centre of my 810 to where the table disappears it's 240mm. That's when I use my 24-70. So looks as if it won't be long enough ? That's why I'm thinking it won't work and will have to fork out for a 50mm prime.
 
amfoto said:
I was looking at the neewer 200mm . Thou when I measure centre of my 810 to where the table disappears it's 240mm. That's when I use my 24-70. So looks as if it won't be long enough ? That's why I'm thinking it won't work and will have to fork out for a 50mm prime.
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A 50mm prime has a wider angle of view than a 24-70mm zoom at 70mm, so if you can't make the table disappear from view at 70mm on the 24-70mm, the 50mm prime will be useless.

I can't help thinking that it's tackling the problem from the wrong end to choose your panorama focal length based on the size and disposition of your table and camera.
 
It's the length of the 24-70 compared to 50mm not the focal length ,,, when I measure edge of table to centre of camera ,, it's 240mm ,,, if I had a 50mm the lens is smaller so a smaller nodal rail would fit. Take it no one uses a nodal with a 24-70mm lens
 
I have no Idea what you mean by disappearing tables ?
I use a proper Nodal Ninja head with my canon !7-55 F2.8 lens when doing interiors, and the rail is only 12cm long
However I only use the lens at the 17mm end.
When shooting out side I usually hand hold it on a monopod. it is all very uncritical.

I am not sure why you would want to cover the entire range to 240mm as you would need a fantastic number of shots to cover a wide pan.
The entrance pupil changes as you zoom and is quite critical in interior work. You certainly need it to be not more than 1/2 mm out, to avoid close parallax stitching problems.
Finding the correct entry pupil distance is not difficult. but can not be rushed. there are many methods of doing it to be found on the web, (one or two clearly rubbish.)
 
amfoto said:
It's the length of the 24-70 compared to 50mm not the focal length ,,, when I measure edge of table to centre of camera ,, it's 240mm ,,, if I had a 50mm the lens is smaller so a smaller nodal rail would fit. Take it no one uses a nodal with a 24-70mm lens
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StewartR said:
What is this table that you keep talking about, and how is it relevant?
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Likewise, what's the table about? 24-70 lens is fine.

The pivot point (entrance pupil) will be somewhere close to the front of the lens. You need a nodal rail to find it accurately.

You just need near and far reference points, line them up, then adjust the pivot point so that they stay lined up when you pan left-right. Easy - takes two minutes, then mark the rail for future reference at key focal lengths. I use the kitchen door frame at about 3ft away, lined up with the patio door frame at roughly 25ft.

Is this the Neewer nodal rail you're looking at? https://www.ebay.co.uk/p/?iid=20152...4&device=c&campaignid=707291931&crdt=0&chn=ps

Probably fine, only thing I would say (apart from the illustration with camera being completely wrong) is that rails with integral clamps can sometimes foul the lens hood if they're too long - effects super-wide lenses mainly so you may be okay. Going the separate clamp and rail route should avoid that as it puts a little more height between the rail and hood, plus you can attach the clamp at different positions if necessary. The only tricky thing about doing it that way might be getting hold of just the right attachment bolt (drop me a pm - I've got a few :)).
 
amfoto said:
It's the length of the 24-70 compared to 50mm not the focal length ,,, when I measure edge of table to centre of camera ,, it's 240mm ,,, if I had a 50mm the lens is smaller so a smaller nodal rail would fit. Take it no one uses a nodal with a 24-70mm lens
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The length of the lens is totally unimportant.
What you need to find is the Distance of the entry pupil to the mounting point of your camera, for each focal length that you will use.

Unless you like very skinny pans, it is far better to mount the camera in portrait fashion on an L bracket.

This is a three shot pan At 17mm, taken hand held out of a site window held in portrait. and cropped
 
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To workout the size of the nodal rail you need. You place camera and lens on a table , lens tip is level with table edge. You then pull camera back slow to the point where u no longer see the table. Live view is easier to see. You then measure tip of table to centre of your camera. This tells u the size of nodal rail you need. Issue is nodal rails only go up to 200mm. So with a 24-70 lens the distance is 240mm .

YouTube video will explain better ,,, thou my issue is ,,, you can't get a rail longer than 200mm , that's why I've asked can a nodal rail only be used with smaller length lens for example a prime

View: https://youtu.be/-ds1xa1JVrQ
 
amfoto said:
To workout the size of the nodal rail you need. You place camera and lens on a table , lens tip is level with table edge. You then pull camera back slow to the point where u no longer see the table. Live view is easier to see. You then measure tip of table to centre of your camera. This tells u the size of nodal rail you need. Issue is nodal rails only go up to 200mm. So with a 24-70 lens the distance is 240mm .

YouTube video will explain better ,,, thou my issue is ,,, you can't get a rail longer than 200mm , that's why I've asked can a nodal rail only be used with smaller length lens for example a prime

View: https://youtu.be/-ds1xa1JVrQ
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You're misunderstanding that Alastair. That table thing is just to find out whether you need a shorter than standard length rail. Using a very wide lens with a long 20cm rail, there's a danger of the rail itself actually appearing in the bottom of the photo. It's nothing to do with finding the entrance pupil pivot point.

My guess is a 20cm rail will be just about right, maybe slightly longer than you need, but the only worry there is fouling the lens hood. Does the lens hood hang down lower than the base of the camera? By how much?

Edit: see the third picture down in this link - shows a typical rail in action, the pivot point, and also illustrates the potential problem with big lens hood https://jimdoty.com/learn/acc/pano1/pano1.html
 
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HoppyUK said:
You're misunderstanding that Alastair. That table thing is just to find out whether you need a shorter than standard length rail. Using a very wide lens with a long 20cm rail, there's a danger of the rail itself actually appearing in the bottom of the photo. It's nothing to do with finding the entrance pupil pivot point.

My guess is a 20cm rail will be just about right, maybe slightly longer than you need, but the only worry there is fouling the lens hood. Does the lens hood hang down lower than the base of the camera? By how much?

Edit: see the third picture down in this link - shows a typical rail in action, the pivot point, and also illustrates the potential problem with big lens hood https://jimdoty.com/learn/acc/pano1/pano1.html
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Cheers ,,, got the question answered lol [emoji23].. thanks all
 
amfoto said:
To workout the size of the nodal rail you need. You place camera and lens on a table , lens tip is level with table edge. You then pull camera back slow to the point where u no longer see the table. Live view is easier to see. You then measure tip of table to centre of your camera. This tells u the size of nodal rail you need. Issue is nodal rails only go up to 200mm. So with a 24-70 lens the distance is 240mm .

YouTube video will explain better ,,, thou my issue is ,,, you can't get a rail longer than 200mm , that's why I've asked can a nodal rail only be used with smaller length lens for example a prime

View: https://youtu.be/-ds1xa1JVrQ
Click to expand...

Like @HoppyUK has explained it is basically what you said but the opposite. So that would be the max length rail you could go for before it shows in the pictures.

There is also a minimum length to achieve the no parallax point, which is the entrance pupil of the lens, I bet the Neewer 200 is the one for you.

Also, bear in mind that I hope you will be shooting these panos in the vertical/portrait format with an L bracket attached to the camera. This will raise the camera up above the nodal slide rail and even at wide angles make you even less likely to see it.
 
Craig_85 said:
Like @HoppyUK has explained it is basically what you said but the opposite. So that would be the max length rail you could go for before it shows in the pictures.

There is also a minimum length to achieve the no parallax point, which is the entrance pupil of the lens, I bet the Neewer 200 is the one for you.

Also, bear in mind that I hope you will be shooting these panos in the vertical/portrait format with an L bracket attached to the camera. This will raise the camera up above the nodal slide rail and even at wide angles make you even less likely to see it.
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Just ordered a 200mm will be here tomorrow,, happy days
 
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