10.27.2009

Digiscoping with a Digital SLR

The Concept

As a concept, digiscoping is as simple as it gets. Put your camera up to a spotting scope's eyepiece and take a picture of what the scope is focused on. However, we often find that in practice things are not as easy as they seem. It's been my experience that one of, if not the biggest challenge of digiscoping, is to get the right mix of scope, camera, and adapter that can easily and effectively be assembled as a complete, photography-ready unit. Why is this?

The Problem


I think the biggest hurdle here is the camera to adapter interface. In today's point-and-shoot camera market there is no uniformity in regards to shape, size, and features. It turns out that camera makers could care less about their products' suitability to digiscoping. As a result, the manufacturers of scopes and digiscoping adapters are forced to come up with intricate, highly adjustable, and often complex universal adapters to fit the plethora of cameras offered to consumers. I'm not interested in making digiscoping any more challenging than it already is. I'll always opt for the route that is fast, simple, and effective.


Pictured above are some of the "universal" digiscoping adapters. Large and mechanically intricate, they offer a less than optimal solution.

The Adapter Solution


The best hardware for digiscoping is that which requires the least amount of forethought or effort to put into use. In regards to camera adapters, the simple tube-style adapters on the market fit the bill perfectly. These tube adapters are simple, both in design and functionality. The premise is a hollow tube screwed onto the front of your camera lens that can slide over a scope's eyepiece, effortlessly centering both lenses at the proper depth. Not only are these adapters easy to deploy, they are compact and lightweight. Question: what's not to love about this type of setup? Answer: it doesn't work with a lot of cameras.

Pictured above are "tube" style adapters offered by Kowa, Vortex, and Swarovski


The Camera Solution


Very few point-and-shoot cameras have the functionality to attach adapters, filters, or boosters to the front lens. The absence of this feature is a design trend that seems to be picking up momentum, and as new models are introduced each year, fewer and fewer of them support filter thread attachments. Here is where a digital single-lens reflex camera (DSLR) fits the bill nicely. Almost all DSLR camera lenses are inherently designed with filter threads that easily adapt to those wonderful tube style adapters. Warning: not all DSLR lenses are suitable for digiscoping. The best lenses are the short focal length lenses. Both Canon and Nikon make 50mm f/1.8 lenses that are relatively inexpensive and perfect for digiscoping. If you're shooting with a Pentax DSLR, you will want the Pentax 40mm f/2.8 “pancake” lens. When using a DSLR for digiscoping, you will need to disable the auto-focus, put the camera on its full manual settings, and set the lens aperture wide open. You will also need to adjust the camera's shutter speed to obtain the proper image exposure.

An exploded view of a full DSLR digiscoping rig, minus a tripod.


Nothing's Perfect


Using a DSLR for digiscoping doesn't come without compromise. DSLR benefits include universal adaptability via a threaded lens and the ability to use, and compose images through, a viewfinder. The drawbacks to DSLR cameras are the inability to use the lens' auto-focus and working with a bigger, heavier camera body. Because of a DSLR's size, I would NOT recommend allowing the camera body and lens to hang unsupported from the spotting scope for any extended period of time.
My current digiscoping set up: Leica 82mm APO Televid with Swarovski DCA and Pentax DSLR

What Are Your Options?


If you've got a DSLR or point-and-shoot camera that uses filter threads, and you need a good digiscoping adapter, I would take a look at the Swarovski DCA, Vortex Razor Digital Adapter, and Kowa DA10 adapter. These three brand-specific adapters accept rings to accommodate various lens thread sizes. I have had some limited luck getting some of these adapters to work with other brands of scopes. For instance, I'm currently digiscoping with the Leica 82mm Televid and, much to my delight, found that the Swarovski DCA adapter fits nicely around the new Leica eyepiece. Be prepared to get creative; if you are going to try to mix and match brands of adapters and scopes, you might need to make your own bushings or modify the adapters in one way or another.

10 comments:

Mike said...

Ben, thanks for writeup about DSLR digiscoping. Been a lot of recent discussions using Panasonic G1 cameras, but I hadn't really entertained idea of DSLR. Am curious why autofocus doesn't work? Not enough light through the scope for camera, or is there some other limitation?
Thanks, Mike

Ben Lizdas said...

Hi Mike,
Because the adapter is attached to both the DSLR camera lens and the scope eyepiece, the lens is unable to move or spin to achieve focus. If you have the autofocus on the lens engaged, the little motor will eventually fail. Hence, you need to turn the focus off on the camera and use the scope's focus mechanism exclusively.

Jeff Bouton said...

Hey Mike,

Even if you were to leave autofocus on though it wouldn't work due to lack of light. Almost all current DSLR autofocus systems are light dependant, that is why all cease to function over over f/8 generally. Even if you have your camera set to say f/2.8 the true aperture is dictated by the 'exit pupil" of the scope eyepiece which is typically near f/11 or higher. The new G1 uses a contrast dependant system like smaller point & shoot cameras rather than light dependant so it's autofocus will still work.
Jeff

Mike said...

Ben, Jeff:
Thanks for the feedback. That completely makes sense. If the camera focus remains constant (infinity?), then that doesn't sound too unreasonable to only focus the scope manually. I was worried one might have to do slight adjustments to both scope and camera each time a subject is found.

Still trying to determine most versatile solution for my needs. I use P&S with DCA on my Swarovski at present, but looking for DSLR-like setup for both digiscoping use and occasional use with long lens. Been stalling on the G1 since there really aren't 600mm effective telephoto options available for it (with autofocus and VR). A true DSLR gives me something new to consider now.

Thanks again.
Mike Blatchley

David said...

Thanks for the writeup on DSLR digiscoping. I'm using a Cannon
40D attached to a Kowa 80 spotting scope using the Kowa adapter. I use the camera "live view" to fine tune the focus and have had good success when I can get enough good light.

Dale Forbes said...

Hi Ben, very interesting post. it seems there is a great amount of personal preference in choosing an adaptor - I personally do not tend to use the DCA.

For DSLR digiscoping, the UCA is a much better solution, imho, as the camera is supported by its base and not the filter thread, and when used with a straight scope, it has the ease and functionality of super-telephoto style photography (granted, higher f and manual focus, but much lighter and more portable).

I have a post on the UCA here:
http://alpinebirds.blogspot.com/2009/06/swarovski-uca-universal-camera-adapter.html

I still have not had the chance to try out the Lumix GF1 with the 20mm pancake lens, but I would imagine that this would make a great digiscoping setup.

Happy digiscoping,
Dale

Anonymous said...

It was very interesting for me to read this post. Thanks for it. I like such themes and anything connected to them. I definitely want to read a bit more soon.

Robin McLeod said...

Great information. I was wanting to get a Leica Televid APO 82 and use a Nikon D3000 but could not find an adapter. Thanks for letting me know that the Swarowski one will fit.

However, I still have a confusion about lenses and the exit pupil interaction. You say "short focal length" and give 50mm as an example. However, the kit lens on the Nikon D3000 is an 18mm - 55m and so is "shorter." However, it is f3.5 and I could use a 50mm f1.8 (or wider). But then comes the exit pupil issue. Several writers have said that this is the determining factor and hence one will get no advantage from a lens stop wider than, say, f12. If this is the case then why would a 50mm f1.8 be better than, say, an 18mm f3.5?

I'm confused.

Cheers.

Ben Lizdas said...

Hi Robin,
The main problem with the zoom lenses is their physical size. Because they are longer/heavier, when attached they will really have a negative impact on the balance of the scope on it's tripod, causing all sorts of stability issues when shooting photos.
Regarding the exit pupil, I'm not sure I fully understand your question. I have to admit though, I'm somewhat of a neophyte in regards to cameras. The recommendation on the 50mm F1.8 is based on trials and experimentation with how the lens systems (camera and scope) interact. There are no doubt, lots of different lens combination's out there that have not been tried and could possibly work quite well.

Anonymous said...

i'm getting excellent results from my vortex razor hd scope with vortex camera adapter using a sony alpha a500 camera body and alpha 50mm f1.4 lens, there is no vignetting at any zoom position, the camera body has a function called manual focus check live view which allows you to enlarge the live view image to achieve absolute focus, i find it superb for fine tuning the focus of the scope, the camera also has a tilting 3" screen, remote shutter release and a great battery that lasts longer than any other dslr on the market
if only it was a bit smaller. eg compact camera size, i may investigate the new NEX5 from sony seeing as the body on that model is tiny