Saturday, March 8, 2008

Digiscoping: Cameras - Features (Updated 2017)

Cameras Today's consumer is inundated with tons of new cameras that hit the market every year. Digiscoping got its start from the use of a compact digital camera (or Point & Shoot) with a 3X optical zoom. Now, mega-zoom cameras up to 24X are available, and most folks think that bigger is better. Not so! Reason? Vignetting! That dreaded black circle or shadow observed along the outside of your camera's viewfinder. A 3X optical zoom camera may show some vignetting at its lowest zoom (1X) with most scopes, but one can get rid of it by zooming in a click or two with their camera's zoom. A mega-zoom camera shows vignetting at all magnifications because the lens cannot get close enough to the eyepiece to align focal planes, so it quickly becomes apparent that they are (generally) considered unacceptable for digiscoping. That said.... Is there an ideal digiscoping camera available? – NO! But there are some ideal features that are available in today's cameras that come close.

Today's camera's provide many features that did not exist in the old classics. More megapixels, brighter and larger viewfinders, 4K Video, and faster frames per second. However, it appears that as the new models are released they tend to start losing many of the features that are desired among digiscopers. When looking for a new digiscoping camera it should have the following features: 

3-4X magnification The CP990 that made digiscoping famous had a simple 3X optical zoom. Any more than that results in potential vignetting problems, increased CA at higher magnifications, and an exponential loss in image quality. Many of today's cameras come w/ 3.5 - 6X optical zooms that should not be discounted, but bring your scope when you test these cameras. Never digiscope using 'digital' zoom. 

Internal zoom The early Coolpix cameras had a fixed outer lens and internal lens elements that zoomed in and out. Those days are gone, as all cameras now have inner and outer lens barrels that move in and out as you zoom through optical magnifications. This makes mounting the camera to the scope eyepiece, at a fixed distance, impossible. Cameras with variable-zoom lenses need to be constantly adjusted to maintain proper lens-eyepiece distance. 

Threaded lens The early Coolpix (and others) had a threaded lens mount that allowed for the attachment of such things as step rings, filters, and optical magnifiers. The early digiscoping adapters took advantage of these threaded elements to connect the camera directly to the scope via tube adapters. Now, cameras with a threaded are increasingly rare, so bracket-type adapters may be needed to fix camera to scope. Luckily, today's digiscoping adapters are getting better at eliminating the need for a threaded lens.

Swivel viewfinder Early digital cameras had a viewfinder that swiveled independently of the camera body and lens. This made it possible to view through the scope at more angles to reduce glare. Many of today's cameras now have adjustable viewfinders that eliminate the need for a swivel-style camera like the CP990. Increased brightness and electronic viewfinders (EVF) make today's cameras usable in bright sunlight.

Megapixels Most digiscopers believe that more pixels are better. It's true, but at a cost. It takes longer for the camera to write bigger files and this can slow down camera speed, especially if you shoot continuously. Wonderful images have been taken with the early 2-4 Mp cameras, and this still true, today. Cameras suddenly jumped to 10-12 MPx while sensor size remained the same; this led to increased noise despite the increased resolution. Today, sensors are getting larger, so a 24 MPx camera can provide stunning image quality with very good noise properties. My current Sony a6300 is a real gem in this department. 

Low noise @ high ISO This is huge, especially when digiscoping on cloudy days or low light. Many cameras suffer from extreme noise at ISO's greater than 200. The Fuji F30 was considered the best camera in this department with low noise at ISO's greater than 800. Today, its possible to shoot at ISO's up to 6400 and generate wonderful images with a 24MPx mirrorless camera. Camera menus also allow a user to automatically select ISO settings to maintain a minimum shutter speed.

Cable release thread Digital camera manufacturers have left this feature off cameras, which means that vibration can be a problem even on a tripod-mounted system. Many digiscopers have resorted to making a bracket for a cable release to reduce camera vibration when taking pictures. An alternative to cable release is the camera's self-timer function. But these tend to require standing in front of the camera and do not provide continuous shooting functions. I myself have never used a cable release and find hand-holding to work just fine (shoot continuously while using long-lens techniques). Newer cameras, like the Sony a6300, have ports that allow electronic cable releases to be used. They also have IR sensors that allow for wireless remote operation. Heck, some cameras even have bluetooth connections that allow control from an iPhone or Android style phone!

CF or SD memory card Compact Flash (CF) or Secure Digital (SD) cards read and write at very high speeds. Look for a camera with these options. The Fuji F30 uses xD cards, and they are painfully slow. Old Sony cameras used Memory Sticks which were incompatible with most card readers.  Today most cameras are opting for the SDHD cards, which are blazingly fast. Cameras with 4K video capability requires FAST memory cards, so you'll have no problem with read/write issues. It used to be important to be able to use a format that could be read by external card readers and computers. SD cards are common in today's cameras and are an extremely reliable medium for storing images at an inexpensive price. I use Scandisk Extreme Pro 16-128 GB cards and am quite happy w/ them! 

Fast read/write It can seem like hours when you've found that Ivory-billed Woodpecker and can't take that perfect shot because the camera is writing your last set of House Sparrow images to disk. The Canon Powershot A620 allowed continuous shooting without having to pause to write to disk. The F30 allows only 3 frames continuous shooting, so there is a 5-10 second delay between bursts. The Nikon P5000 and P5100 were considered two of the best digiscoping cameras a few years ago, but only allowed 0.8 fps shooting.  Mirrorless cameras today can now shoot 10-20 fps and have buffers that can handle hundreds of frames before they bog down. Buy the fastest cards you can find to get the most out of your camera's buffer.

Customizable menus The old Canon Powershot cameras allowed you to set up your own menus that were stored in the camera. Turn on the camera and shoot. The Nikon Coolpix CP990 and F30 were frustrating to use because all settings are lost when the camera is turned off, or switched to a different shooting mode. Setting up shooting menus in the field is not a good idea, especially when that IBWP has just appeared. The newer camera models now allow customizable menus to be saved when the camera is turned off. Multiple user settings are common in most camera models so you can quickly switch settings under  changing conditions. 

Continuous shooting The Canon Powershot cameras allowed Continuous shooting as long as you had memory. The F30 only allowed 3 Frames (top three or final 3). It's not necessarily a bad thing, as you end up with fewer images to review (and potentially process), but there are times when you don't want to have to wait for the camera to write images to disk. Today's Micro 4/3  or "Mirrorless" cameras can provide continuous shooting up to 20 fps in normal shooting or 30-60 fps in limiting modes. With 4K video you can now select individual frames at 8-12 MPx resolution using Photoshop.

Instant firing The Coolpix cameras were frustratingly slow when it came time to snap a picture. Press the button, wait 3-5 seconds for the camera to lock in focus, set exposures, take a diagnostic, have a cup of coffee, etc., then fire. Today's cameras are much, much faster, and operate much like the more expensive DSLR's. A tip: depress the shutter half-way to lock in focus, then fire when your moment is upon you.

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