I recently received my copy of the Interstellarum Deep Sky Atlas by R. Stoyan and S. Schurig (Oculum – Cambridge University Press) and I promised you guys a full report. IDSA is a full sky, deep sky ( stellar magnitude 9.5) star atlas, printed as a scale of 1.5 cm/deg. It is roughly comparable to Uranometria 2000.0, 2nd Ed. Full technical specifications and a detailed comparison with U2K2 are available at the publisher’s website at http://www.deepskyatlas.com/ . I have the “Desk Edition”. A pricier “Field Edition”, printed on dew-proof paper, is also available.
The first, out-of-the-box impression of IDSA is very positive. It is absolutely gorgeous, printed on glossy paper and beautifully color-coded. It is compact, about 1′ x 1′ x 1″ and although lays-flat spiral bound with a cardboard cover, appears to be sturdily put together. Although not quite as deep as U2K2, it is much smaller and lighter and it will easily fit in your observing kit or travel bag. The color symbology is reportedly designed to be easily visible even in red light. The graphic design and printing is first-rate. Check the website for some sample illustrations.
Navigation through the atlas is easy, with generous overlaps, useful index maps and pointers to adjacent map numbers and it is “threaded” so Right Ascension decreases to the right as you turn the pages, but increases to the left on each chart (east, as apparent to an observer facing south). Adjoining facing pages display an unbroken section of sky with RA increasing to the east. It is clean and easy to use, practically instinctive.
Although not quite as comprehensive as U2K2, especially as far as faint galaxies are concerned, it is much easier to use in the field, where you may prefer not to take the more expensive, delicate and bulky Uranometria.
On the negative side, IDSA uses color coding and label font to divide deep sky objects by visibility into 4 categories; visibility in 4″, 8″ and 12″ apertures respectively, with a 4th class for dimmer but special objects. Although this might be useful for beginners, I find it a rather subjective categorization, and only adds to confusion and clutter. Another minor complaint: the main stars of the constellation asterisms are connected with straight lines to help recognize the figures. Although this is useful in the index maps, the individual map sheets do not require this, and it only adds to the visual clutter.
Still, these are only minor quibbles on my part, I recommend the IDSA, except perhaps for experienced observers on a budget who already own U2K2. For your observer’s kit, or while traveling, this is the item to carry, and it is still a beautiful enough example of the publisher’s art to leave on your coffee table.