Digiscope or Superzoom Bridge Camera for Birding?

A correspondent who sells secondhand optical equipment for birding on eBay tells me that the prices of digiscoping adapters for major brand telescopes are falling. He thinks the rise of the Superzoom ‘Bridge’ cameras I have discussed in this blog is the reason. The extra focal length gained by using a scope (see my Post of 19 August 2012) is now of marginal advantage when we can get the 35 mm equivalent of 1200 mm focal length from a superzoom. Add the large number of pixels captured and the fact that there is image stabilisation in the superzoom, then I can see why the digiscoping may become a thing of the past fairly quickly.

It is obviously much quicker to point a superzoom camera at a bird than it is to mount the scope on a tripod, aim and focus the scope, attach the camera by whatever attachment you have and then press the shutter.

Another correspondent says he has just had a rare bird accepted from a photograph at 1000 mm equivalent with his Nikon P510 handheld.

Over the next few weeks I will eventually get round to comparing my two systems (Nikon P50 Superzoom vs Leica Televid and Panasonic Lumix on adapter) side by side at the mouth of the river and in the garden.

Cameras for Birding: The ‘Bridge’ Camera Zoom War: Panasonic Lumix FZ72 Joins The Fray

Panasonic have now joined the zoom war in the increasingly popular superzoom ‘bridge’ camera category that is so good for birding.

I have added this camera to the table I prepared for my post of 9 March 2013. These are the key features as far as using the camera for birding are concerned but it would be good to know how it handles noise at high gain (ISO setting) and the chracteristics of its autofocus.

	Nikon P520	Canon SX50	Fuji HS50	Sony HX300	Panasonic FZ72
Optical Zoom (equiv)	24-1000	24-1200	24-1000	24-1200	20-1200
Max Aperture	3-5.9	3.4-6.5	2.8-5.6	2.8-6.3	2.8-5.9
Sensor Size	1/2.3	1/2.3	1/2	1/2.3	1/2.3
Resolution (Mpixels)	18.1	12.1	16	20.4	16.1
Output Size (pixels)	4896x3612	4000x3000	4609x3456	5184x3888	4608x3456
Stablisation	Yes	Yes	Yes	Yes	Yes
Output	JPEG	RAW/JPEG	RAW/JPEG	JPEG	RAW/JPEG
Video	Full HD	Full HD	Full HD	Full HD	Full HD
Weight g	550	595	758	623	562

I haven’t seen a review of this new camera yet but how the market has changed in little over a year: from only a Nikon to a five superzooms from all the main manufacturers. Given the reputation of the Lumix series, I suspect this new one will provide the others with stiff competition.

Cameras for Birding: The Zoom War Hots Up — Sony HX300

For bird and other wildlife watchers needing a light camera to record sightings, there was no choice a year ago. There was only the trend-setting Nikon P510 with its 24-1000 mm (35 mm equivalent) lens.

'Bridge' cameras have been selling very well (much to the tut-tutting of the mainstream photographic magazines who do not realise that carrying heavy binoculars and, often, a tripod and telescope as well means that an SLR with a long lens (often of inadequate length at that) is out of the question).

Canon soon followed Nikon, then Fuji and now Sony have followed with basically similar products; Nikon have followed up the P510 with the P520 (see my posts of 19 February 2013, 18 October 2012, 31 August 2012, 15 July 2012).

The Sony HX300 will be available in UK in early April. It is very difficult to say which model has the edge at the moment. The new Sony has more pixels but to see whether that compromises noise reduction we shall have to wait for the reviews. Disappointingly, it does not offer RAW, although with a 1200 mm equivalent lens and an output of 5184x3888 pixels, it could give that extra push that birders are always striving for. It is heavier than the Nikon but not so heavy as the Fuji

Here is my extraction of data from the technical details that are important to birders:

	Nikon P520	Canon SX50	Fuji HS50	Sony HX300
Optical Zoom (equiv)	24-1000	24-1200	24-1000	24-1200
Max Aperture	3-5.9	3.4-6.5	2.8-5.6	2.8-6.3
Sensor Size	1/2.3	1/2.3	1/2	1/2.3
Resolution (Mpixels)	18.1	12.1	16	20.4
Output Size (pixels)	4896x3612	4000x3000	4609x3456	5184x3888
Stablisation	Yes	Yes	Yes	Yes
Output	JPG	RAW/JPG	RAW/JPEG	JPEG
Video	Full HD	Full HD	Full HD	Full HD
Weight g	550	595	758	623

On Amazon UK prices of these models today are: Nikon P520 £355 (the P510 is still available at £239); Canon SX50 £362; Fuji HS50 £470; Sony HX300 £419 (pre-order).

Fuji HS50 - The Zoom War Continues

Fuji has now joined Nikon (P510) and Canon (SX50) in producing a 'bridge' camera with very long lens that is ideal for wildlife photography (see my post of 14 October 2012). I have sung the virtues and few vices of the P510 — it was first on the scene and clearly established that there is a demand for light cameras with a long lens (and, of necessity, a small sensor).

The specifications of the Fuji HS50 are very similar to the P510 with (as with the SX50), a few key differences: zoom range of 24-1000 mm in 35 mm equivalents; a slightly wider maximum aperture (f2.8 at 24 mm, decreasing to f5.6 at 1000); similar size of output (4609 x 3456). Like the Canon, but not the Nikon, there is RAW and full HD (1080) video output. In terms of weight, the Nikon (555 g) scores over the Canon (595 g) and the Fuji (758 g).

The prices of these cameras today on Amazon UK were:

Fuji HS50 £419.99
Canon SX50 £394.99
Nikon P510 £235.82

I also see that the Nikon P510 has disappeared from the WEX website. It is still on the Nikon UK list but its obvious replacement, the P520 (labelled 'new') is a disappointment. Nikon have gone for the same basic camera with the same lens but have added 3D and a few other irrelevant features (why? — stereoscopic photography has only ever had short waves of popularity and already looks on the wane again). An opportunity to add RAW output has been missed. For a price today of £399 for the P520, the Fuji and Canon seem more suited to the wildlife market. Nikon may have missed a trick after having been first in the field.

The value of a camera like the P510 to the birdwatcher wanting to get a picture quickly before a bird flies away has been demonstrated by my Number 2 son. The P510 I so kindly bought him for his birthday has already been used to provide evidence, acceptable to an expert committee, for a range extension of a rare bird, as well as allowing rare migrants to be identified in the comfort of air-conditioning and with the assistance of the full range of reference books. He keeps the camera set up with a central 'sniper' autofocus site when he is out, as I described in my post of 31 August 2012.

With Canon and then Fuji joining in the zoom war, will Panasonic come up with something longer than 600 mm to join them?

Focal length of digiscopes compared to camera lenses

Does that mean you don’t have to fiddle about putting a camera on the telescope, then?

That was the question asked when I was showing off the capabilities of the Nikon P510 at the 35 mm camera equivalent of 1000mm. The question was also loaded in that it implied I would not need to buy a camera for digiscoping to replace the old Canon Ixus that fitted the scope awkwardly. The follow-up question — Surely that 1000 mm lens is as good as a scope isn’t it? — sent me in search of data. Evidence that useful as the 1000 mm is, it could not match the focal lengths of a telescope plus camera was needed. What is the focal length of a digiscope set-up in terms equivalent to a 35 mm full-frame camera?

I thought I could remember that the formula was the focal length of the camera lens multiplied by telescope magnification (with the focal length of the camera lens expressed in 35 mm full-frame camera equivalents). Sure enough, that is the formula given on the Swarovski website:

To determine the equivalent focal length for a digital camera compared to a 35 mm camera, you need to carry out a few calculations. Each digital camera has a 35 mm equivalent figure. For the Nikon P-6000, for example, the 35 mm equivalent figure is 28–112 mm. Since the Nikon P-6000 has a digital focal length of 6–24 mm, this results in a factor of 4.66 (28 mm divided by 6 mm). This factor or the 35mm equivalent focal length is usually stated in the camera’s user manual.
In this case, the equivalent focal length is the adjusted focal length of the digital camera multiplied by the factor 4.66. Example: The Nikon P-6000 is set to a focal length of 14 mm. 14 mm x 4.66 = 65.2 mm focal length equivalent for a 35 mm camera.
To obtain the entire 35 mm equivalent focal length from your digiscoping equipment, you need to multiply that focal length by the magnification of your scope.
Example: Your telescope is set at 20x magnification. 65.2 mm x 20 = 1,304 mm total 35 mm equivalent focal length
To determine the total digital focal length of your digiscoping equipment, you simply need to multiply the focal length of your digital camera by the magnification settings of your telescope.
Example: Your digital camera is set to 14 mm focal length; the telescope is at 20x magnification: 14 mm x 20 = 280 mm total digital focal length

           http://www.swarovskioptik.com/en/digiscoping_faqs

So I thought I would try it out in practice, because as, we shall see below, this is not the only formula doing the rounds on the internet. The old Ixus is ‘on loan’ and I had to use the only camera in the house that was vaguely suitable — my wife’s underwater Panasonic Lumix DMC-FT3 with its square lens housing. I managed to hold this to the eyepiece and zoom in until there was a full frame without vignetting. I then looked at the metadata. The camera focal length was 7 mm. The factor needed to convert to 35 mm equivalent was calculated from the actual zoom range of 4.9-22.8 mm and the stated 35 mm equivalent of 28-128 mm. 28/4.9 is 5.71 and 128/22.8 is 5.61 so I took the mean of 5.66. The telescope magnification was 40. Therefore, the 35 mm equivalent focal length of the whole set-up was 5.66 x 7 x 40 = 1584 mm.

The story does not end there because the Google search showed other sites which showed calculations for focal length. In the first (http://www.birddigiscoper.com/2009/08/digiscoping-math.html), I could not see how the writer had derived the formula or the constants used. Putting the same values into his formula I came up with a focal length of 2263 mm! Another website (http://www.digibird.com/primerdir/primer0.htm) provides an Excel spreadsheet which came up with 1720 mm. In the latter case, the difference is in the way the 35 mm equivalent focal length of the camera lens is calculated but since I do not know how a constant used for the calculation was derived I cannot comment further.  These cases demonstrate how dangerous the internet is for spreading and retaining incorrect information. I have shown the web addresses but not shown them as links for this reason.

Just in case you are wondering whether Swarovski got it wrong and the other guy is right (even though I could find no basis for the formula he came up with), I did stand in the same place with my Nikon P510 and take a picture at 1000 mm equivalent of the same object at the bottom of the garden. I then measured the size of the object in relation to the width of the frame on the screen. In my crude Lumix digiscoped shot, the object occupied 0.58 of the total width; in the Nikon it occupied 0.36 of the width. Dividing one by the other, 0.58/0.36 = 1.61. Thus, the focal length of the digiscope was 1.61 times that of the Nikon or 1610 mm, remarkably close to the calculated 1584 mm given the crudity of the size measurements. Clearly, the formula given by Swarovski is the one to use when calculating the focal length of a digiscope set-up when using a digital compact camera. I just hope that people find that one first in any Google search.

The focal length of any digiscope set-up can be calculated from the camera focal length (found in the metadata after taking), the manufacturer’s stated zoom range in 35 mm equivalents and the magnification of the telescope eyepiece.

And, just in case you were wondering, great as the 1000 mm equivalent lens of the Nikon P510 is for birds, it does not replace the digiscope entirely. Much longer focal lengths can be achieved with the latter but whether there is enough light or time to set up the scope is another matter.