Luminous Landscape Forum

Equipment & Techniques => Landscape & Nature Photography => Topic started by: dreed on February 02, 2019, 02:20:40 am

Title: Using two cameras for wide angle
Post by: dreed on February 02, 2019, 02:20:40 am
For many wide angle shots, doing the panorama stitching thing by rotating the camera works.

Depending on budget, going really wide might also be an option.

But what about using two cameras next to each other, with an overlapping view.

Does software manage merging that ok?
Title: Re: Using two cameras for wide angle
Post by: dreed on February 02, 2019, 05:21:44 am
I have found one reference:

https://www.diyphotography.net/filmmaker-shot-two-dslrs-side-side-two-years-make-amazing-panoramic-timelapse-la/
Title: Re: Using two cameras for wide angle
Post by: Bart_van_der_Wolf on February 02, 2019, 06:30:32 am
For many wide angle shots, doing the panorama stitching thing by rotating the camera works.

Depending on budget, going really wide might also be an option.

But what about using two cameras next to each other, with an overlapping view.

Does software manage merging that ok?

Hi,

It would only work for distant subjects, anything close to the camera would have parallax errors. Always, when the entrance pupils of the lens(es) move between shots, parallax errors are the result for anything except a flat plane. At a distance, depending on the magnification by the focal length, the parallax errors would be too small to notice.

When the entrance pupil differs between shots, only a single plane can be aligned perfectly. So it would work on flat plane subjects (even at an angle), but anything with depth will cause issues.

I have found one reference:

https://www.diyphotography.net/filmmaker-shot-two-dslrs-side-side-two-years-make-amazing-panoramic-timelapse-la/

That demonstrates that by crossing the optical axes the displacement between the entrance pupils is reduced, the wide angle shots reduce the magnification factor, and the lack of close foreground detail will reduce the visibility of the parallax errors.

Cheers,
Bart
Title: Re: Using two cameras for wide angle
Post by: stamper on February 02, 2019, 09:50:19 am
The two cameras would need to be identical otherwise there would be differences in colour and hue?
Title: Re: Using two cameras for wide angle
Post by: Bart_van_der_Wolf on February 02, 2019, 10:40:01 am
The two cameras would need to be identical otherwise there would be differences in colour and hue?

Yes, well close enough anyway. A good Raw converter can equalize the differences between two overlapping images, and a good stitching application (e.g. PTGUI) is also able to compensate for small differences in exposure, and blend between them. Even two slightly different focal-lengths or focus distances (that lead to magnification differences) will be handled by the stitching application.

Cheers,
Bart
Title: Re: Using two cameras for wide angle
Post by: gchappel on February 02, 2019, 11:19:46 am
I read an article somewhere describing using two and/or 3 cameras together for shooting panos.
Only needed and useful for controlling motion.   There are easier/lighter/cheaper/smaller ways to do it with non moving subjects.   
He did have some spectacular wave panos.  They looked terrific.  Would not be possible with a single camera pano due to the wave motion.
I believe he also had some with crowd motion. 
The images were incredible, but that says more about the photographer than the equipment setup.
Gary
Title: Re: Using two cameras for wide angle
Post by: dreed on February 02, 2019, 10:29:45 pm
I read an article somewhere describing using two and/or 3 cameras together for shooting panos.
Only needed and useful for controlling motion.   There are easier/lighter/cheaper/smaller ways to do it with non moving subjects.   
He did have some spectacular wave panos.  They looked terrific.  Would not be possible with a single camera pano due to the wave motion.

You've hit on my exact problem - waves. As per the attachment, because waves are always in motion, even the very short time span between a small rotation makes a visible join flaw.
Title: Re: Using two cameras for wide angle
Post by: Bart_van_der_Wolf on February 03, 2019, 07:25:54 am
You've hit on my exact problem - waves. As per the attachment, because waves are always in motion, even the very short time span between a small rotation makes a visible join flaw.

Ha, I've done a case study for a fellow photographer who frequently shoots luxury yachts from a helicopter, and was seeking a solution to increase the pixel-count of his images beyond 50-100MP, hand-held mind you ... That also included building a rig with multiple cameras to mount on the ship outside the railing, thus catching both waves and ship. But it's very hard to get the entrance pupils of the different lenses close enough to reduce the parallax error on close subjects.

For regular stitches, one needs to find the cycle between waves, and time the shots accordingy. Also exposure bracketing with 1/3rd stop increments may allow picking a better-timed overlap.

Cheers,
Bart
Title: Re: Using two cameras for wide angle
Post by: LesPalenik on February 05, 2019, 01:08:04 pm
If the wave is at least 20-30 meters away, you should be able to use 2 cameras side by side and trigger them by a remote or even a cable release.
The difficult part is to align them correctly (allowing for 20-35 degrees overlap. The safest method would be to mount both cameras on some solid rig and do the alignment using some object on the beach, roughly the same distance as the intended distance to the wave and then turn the entire rig towards the waves. 

If you can rent Roundshot VR Drive panoramic head, that one has a speed mode which allows shooting at high shutter speeds (without stopping the rotation after each exposure) while the camera turns.
However, the simplest option for an action shot in panoramic format would be a 6x17 panoramic 120-film camera. One camera, one shutter click, no parallax error, no stitching needed.
Title: Re: Using two cameras for wide angle
Post by: dreed on November 24, 2019, 05:35:42 am
However, the simplest option for an action shot in panoramic format would be a 6x17 panoramic 120-film camera. One camera, one shutter click, no parallax error, no stitching needed.

These are not cheap, even second hand ones on eBay are many thousands of dollars. And then there is the problem of film. Where do you go to process 120 film these days?

The one shutter clitch/no parallax/no stitching is nice, but the price is not. What do you do when the price isn't right? DIY!

For the brave, here's how to build your own 6x17 landscape camera:

https://www.instructables.com/id/DIY-6x17-Panoramic-Film-Camera/

... not sure I'm ready for that just yet!
Title: Re: Using two cameras for wide angle
Post by: Jonathan Cross on November 24, 2019, 05:30:38 pm
Intrigued I just looked up a hasselblad Xpan in the uk.  They are priced between £3500 and £6000 depending on how many lenses. Not cheap is definitely right!

Jonathan
Title: Re: Using two cameras for wide angle
Post by: dreed on November 25, 2019, 08:04:42 am
This is the contraption I've come up with thus far (and it works!)

The chosen cameras are Canon M6. For a couple of reasons:
0) it has a remote control socket (!)
1) remote control socket is 2.5mm stereo plug so this makes it easy to get plugs (unlike N-3)
2) EOL product, therefore cheap(er) - eBay/craigslist FTW.
3) small, lightweight, so carrying multiple isn't a huge burden
4) wide angle lens selection was the best and most affordable for all mirrorless cameras (I did a lot of research on this one) Lots of mirrorless cameras everywhere, but a very small number of lens at the 16mm (FF) view. The 11-22 was the killer lens here.

The two cameras are screwed onto a piece of cast aluminium that itself is very strong. Light weight and very strong. That's then screwed onto the tripod plate.

There's some right angle 2.5mm - 3.5mm plugs in each remote socket and then a bit of a hack job in terms of cable with the far end being another 2.5mm socket. If I wanted to get rid of the nastyness in the middle, I'd probably have to terminate each cable to accomodate a stereo splitter. Why didn't I just use off the shelf cables? Length. I didn't want to end up with 3' of cable from the camera to the splitter, then another 3' of conversion cable to plug the remote into.

Still yet to do will be some kind of handle to guide the aluminium plate up and down.
Title: Re: Using two cameras for wide angle
Post by: Lightsmith on December 05, 2019, 06:14:21 pm
One can do much the same with a tilt shift lens. Shift left and take a shot, shift to the center position and take a shot, shift to the right and take a shot.
Title: Re: Using two cameras for wide angle
Post by: LesPalenik on December 09, 2019, 11:28:08 pm
Intrigued I just looked up a hasselblad Xpan in the uk.  They are priced between £3500 and £6000 depending on how many lenses. Not cheap is definitely right!

Jonathan

I wouldn't bother with Hasselblad Xpan. This camera uses only a 24x65mm film frame. You may as well buy a much cheaper a 6x7 or 6x9 film camera with a wide lens, and crop the image to the desired height. Or even use a high-resolution (50-60MP) digital camera and then crop it to a pano format. 6x17 camera format is substantially larger than the 24-65mm frame and allows also for larger prints.
Title: Re: Using three cameras for wide angle
Post by: dreed on December 31, 2020, 09:12:47 am
I ended up doing this with 3 cameras on a bigger plate due to the weight of cameras.

What's the benefit of this approach?

#1 everything in the scene gets captured at approximately the same time.

This means that there is less to deal with in terms of moving boats, planes, waves, birds, branchs, leaves, etc. It makes HDR+panorama merges much less tricky.

I've attached some screen shots of what it looks like to work with in Lightroom. There's a bit of distortion still but it isn't too bad.

What's also important is that for a wide angle panorama, to get the right ratio (3:1 - ~9000x3000) would mean heavy cropping of a standard 3:2 image. In the iamges shown I'm using 3 * 24MP APS-C sensors @28mm. My math tells me this is about the same as would be a single 17mm lens in front of a 54MP sensor. Cost was about 1/4 of a Sony A7RIV + lens - and a lot more fun!
Title: Re: Using two cameras for wide angle
Post by: kers on December 31, 2020, 10:23:37 am
Your setup is especially good for stereo photography; there is serves well.
The distance of the lenses should be about eye distance or some cm larger. Depending on the distance of the subject you can extend the lens-distance.
Aereal stereo photographs are made with one camera taking shots some 100 m apart. In this way you can see the landscape as it was a miniature.
Title: Re: Using two cameras for wide angle
Post by: GuidoBee on January 01, 2021, 01:51:30 am
Great results.  I am impressed with how well the last, merged, image came out.
Have a great and safe new year.
Title: Re: Using two cameras for wide angle
Post by: dreed on March 15, 2021, 06:14:02 am
I haven't yet explored the limits of how wide I can go with this but as you can see from the first two, it is over 135 degrees view, rectilinear, moment in time, without wasted acres of pixels above and below.

Experience with merging suggests that multiple shots are required to get the timing of all cameras correct as they all have individual brains and sometimes there is a bit of slowness in one of them.

From some of the images, I'm getting somewhere between 3:1 and 4:1 as the final aspect ratio, with over 15,000 pixels wide on a 50+MP image.