Focus is so darn important in Hd. I am considering getting a range finder to assist this.

Was wondering if anyone is using one and what models are suitable for what we do.


Dale Guthormsen

I use a Nikon 2000. Been superceded but that's just the way things go.

Works great.

The things to consider:

Closest measuring distance:

My Nikon won't work at less than 10 metres, which in practice isn't an issue as at less than 10 metres I can get focus pretty good by eye.

Accuracy & Maximum range:

My Nikon is accurate to .5 of a metre out to 1200 metres, which is great as my Canon XH A1 has manual focus distance readout to 950 odd metres and believe me, a metre, even at that range, really shows in the footage.

There are units out there that will work down to less than a metre and are accurate to something like a couple of millimetres at 200 metres , tho' a 200 metre maximum range is way too low for my needs.

I've found it indispensible and it lives in it's holster on my hip whenever I'm shooting. It's amazing how it can pick out the .5 metre distance difference between any two objects at 300 metres and have one spot on and the other soft, or allow you to dial in the correct mid point if you want to capture both in reasonable detail.

I had expected the camera manufacturers to start incorporating them into the camera optics systems by now, guess they never will.


CS

Dale,
An interesting concept, but I don't understand 2 things. If you get an accurate range with a stand-alone range finder, how do you tell the camcorder to focus at the value you find? With wildlife, the range is always changing. Do you need an assistant to do this?

I'll let Dale answer for himself, but just put in my 2 cents................

Depends on what type of wildlife and the circumstance of the terrain, not that a rangefinder's use is limited to wildlife, mind.

I video a lot of fur seals, sea lions and leopard seals.

The first group are usually to be found on rocky outcrops, mostly surrounded by water.

Depending on the terrain, the closest one can approach without spooking them is of the order of 100 - 200 metres.

With the rangefinder I can scope the closest point and the furthest point of the outcrop and the actual distance to each individual in a group.

Having built up a 3 D image of exactly what on the outcrop is where in distance, as each individual moves relative to the camera I can vary the focus to track one individual in perfect focus wherever it goes.

It requires the ability to keep all those measurements in your head and a VERY smooth hand on that focus ring and an eagle eye on the distance readout (in the camera viewfinder) whilst at the SAME TIME watching the state of play and figuring out who is going to do what next - or not AND tracking the action with the pan arm as smoothly as possible AND keeping an eye on the exposure.

It's busier than a one armed paper hanger, but, when it comes off, it's magic.

Likewise, on non wildlife shoots, say, a scene where a trio of people walk across a square diagonally from left to right across my field of view, I "pull focus" on their start point, intermediates and end point and use that distance data to track either the lead talent or the one talking, keeping them in tack sharp focus throughout.

Basically it's like having your very own focus puller in a can.

Interestingly, we've had maybe 3 or 4 international film crews filming in Dunedin in the last year or so and each crew has been pulling focus with...........tada, an IR rangefinder!


CS

Chris, do you have a link for your rangefinder? My Google search turns up rangefinder CAMERAS, not laser rangefinders.

Nikon | Sport Optics | Laser Rangefinders (http://www.nikon.com/products/sportoptics/lineup/laser/index.htm)

Think on reflection mine is the 1200, thought it had been superceded.

The best search reference is "rangefinder".


CS

Thanks Chris... very interesting. It never dawned on me that these would actually work for our industry... And if it HAPPENED to make it's way into my golf bag when I wasn't using it for video...

These are for those who need to focus on the hairs on a gnats kneecap @ 100 yards..............

Laser Distancemeter - Leica Geosystems - Leica Geosystems (http://www.leica-geosystems.com/en/Laser-Distancemeter_5061.htm)

but don't need ultra long range.

Shaun - there you go, a truly multi function, multi disciplinary tool!


CS

Good evening,

I picked up a range finder today, its good to nine hundred yards, as Chris said the xlh1 measures that far out so it seemed right. I will try it out in the field during the next few days.

Chris' explanation is better than anything I could write. I just want to be certain I am actually right, if not then get it so. I like to pull focus often and this will make that 10 times easier!! I will use this mostly when shooting wildlife from a blinds. Also when I shoot outdoor events too.


Thanks for the responses.

Dale Guthormsen

Chris,
Thanks for the explanation. Now I see how it works...the camcorder has a distance readout in the viewfinder, and you just reproduce the rangefinder data. Unfortunately my Canon XLH1 using 35mm lenses has no such feature. At the large distances you are shooting, doesn't autofocus do just as good a job?

One more question about the rangefinder, with a closer subject. Let's say your subject is
(by rangefinder) 31.7 feet away. The camcorder distance readout doesn't give fractions. You can get 31 feet or 32 feet. You have to interpolate in between. How is that any better than the ability of your own eye to chose the sharpest setting?

Ah, well, auto focus.

At 100 to 200 metres a sea lion (even a REAL big one) doesn't occupy enough of the frame to let auto get a grab on it. If there's 5 grouped together it will but then you have the problem of where, exactly, it's going to focus if the group is say, 5 metres deep.

Most of the time auto just hairs off into the distance and focuses on nothing whatsoever.

As for focusing by eye, I don't know what sort of screen is on the H1 but the screen on the A1 leaves a great deal to be desired, even with peaking and magnify kicked in.

I did a great many objective tests when I first got the rangefinder (which I bought precisely because I was getting so many out of focus shots)- focusing by eye, measureing with the finder and altering the focus to match the figure shown. The finder won every single time (I have no hesitation in admitting my eyes probably aren't functioning as well as they used to, sadly).

The difference to the eye on that diddy little screen was miniscule, magnified up to a 46" HD screen it screamed "SOFT".

As for interpolation, you need to make a swift mental calculation of what you actually want in the frame and what you want focused and what can be soft. Is that 31.7 the tip of it's nose, central body or tail? Is it side on or head on?

Setting the focus to 32 gets you sharp from 31.5 out to 32.6, setting it to 31 gets you 30.5 to 31.6 (dependent on zoom setting and aperture, of course).

With a bit of practice it just becomes completely automatic.


CS

I have been following this debate with interest.

In January I was using my EX3 to record the nest building activities of a grey fantail. As well as using the supplied zoom I used a fairly new Nikon F4 300mm and either a older manual 105 mm Micro Nikkor or a fairly new 105 mm Micro Nikkor auto focus VR lens. My working distance varied but was around 10 m. Focusing was not that easy partly due to the light wind and that fantails build on fine branches, but I do not see how a range finder, as good as they are, could have helped in these circumstances. The Nikon laser 1200S specifications say that it measures in 0.5 m increments and even if it had finer resolution the focusing scales on my lenses are far too crude to make use of the information.

One of the reasons I had troubles was because the focusing mechanisms in the newer Nikon lenses were a little vague and klunky no doubt due to their autofocusing systems (I was using the manual option). Only a very small rotation of the lens barrel made a lot of difference to the focus. I found the focusing action on the earlier model manual 105 Micro Nikkor easier to adjust finely.

To make focusing more critical I have replaced the supplied EX3 viewfinder lens with a more powerful one and if I focus at full aperture (using the ND filters) I can pick a change in subject distance of about 4-5 cms at a distance of about 10m using the F4 300mm Nikon.

You're quite correct, I can't see how one would have been any use in those circumstances.

The reason it works so well with the Canon A1 is that the (non removeable) servo lens readout increments in .1 metre steps from 0 to 10 metres, then 1 metre increments thereafter.

Up to 10 metres most targets when fully zoomed in on have more than enough detail to enable accurate focus, so no external help is required.

After that it goes without saying that the target is getting smaller and smaller and things get a bit iffy with the less than perfect LCD.

In your case with no camera generated focus figure due to manual lenses you're really up against it.

If I could mount my Nikon 18- 200 zoom to my A1 I'd probably find it unusable as well without the benefit of a SLR prism giving me WYSIWYG.

In fact, my missus Nikon 8700 only has LCD or electronic viewfinder and if the auto focus doesn't, that's it, game over 'cos you sure can't use either of the displays to focus.


CS

Hi Alastair,

I am considering replacing my Canon XLH1 with the EX3 largely because of the Canon's horrid viewfinder. You refered to yet a further improvement over the EX3 viewfinder. Mind mentioning what it is?

Hi Steve,

The modification involved replacing the original removable loupe assembly with another that uses the same attachment points, so that the experiment is reversible. The new lens has a focal length of about 4” and nearly doubles the size of the image. The lens selected was originally made to give an extra 2X magnification to a dissecting microscope as used in laboratories.

As the new loupe is about 2.5” shorter than the original the user’s eye position is correspondingly further forward – an advantage for hand held work but a disadvantage for tripod use. When the warranty expires I might try re-mounting the finder and use a short cable for more versatility.

I have attached two pictures of the assembly. The eyecup is not shown. I use a single tube mounted support for my 300 mm lens. As its axis is parallel to the lens axis it can be used as a sight to locate the point of interest. A third use for this is that it acts as a suitable support for the left hand when handholding, The support tube fits between thumb and forefinger, the adjustable black collar spreads the weight, the arrangement leaves the fingers free for lens tweaks. With the modified loupe the eye is further forward so that some of the camera’s weight is taken on the shoulder.

http://www.dvinfo.net/forum/images/attach/jpg.gif
http://www.dvinfo.net/forum/images/attach/jpg.gif

Now that you've had some time to play, what's your conclusion?

Good or not?


CS