INTES Micro M603 6Inch and M809 8Inch and Maksutov Cassegrains

Russian-produced Maksutov Cassegrains enjoyed a great deal of popularity among amateurs during the 1990s. With the coming of the Chinese MCTs, however, much of this interest fell off, and Russian MCT makers Intes and Lomo have now apparently quit the business. There are still some Russian Maks on the telescope market, however, in the form of high-quality instruments produced by Intes Micro of Moscow.

Intes Micro produces an extensive line of MCTs, ranging from a compact 5-inch to a gigantic 14-inch. The Intes Micro telescopes with the most appeal to amateurs, however, are the M815 8-inch and, especially, the M603 6-inch. The M603 features just about everything amateurs have wanted in a Mak OTA and that they have often found lacking in the Chinese imports: excellent build quality, top-grade optics, and a reasonable price (about $1,300 from the scopes' U.S. importers ITE and Teton Telescope (see Appendix 1).

Yes, this price is comparable to that of the 180-mm Synta, and yes, aperture is important, but in this case it might be wise to think about giving up that inch. Chinese optics can be very good, certainly, but they are probably not as consistent as those in these telescopes. A 1/8-wave accuracy is usual for the M603. The mirrors in the Intes Micro OTAs are not standard Pyrex, either, but Sital, a glass with better thermal characteristics, something that helps with the typically long Maksu-tov cooldown. Also, the M603's focal ratio is a comparatively low f/10, making the scope more versatile than most other MCTs. The primary obstruction in this CAT is somewhat large at 36% (necessary to get the focal ratio down to f/10), but this does not seem to hurt contrast much.

Tube mechanics are also noticeably better in the Intes Micros than they are in the Syntas. In addition to the normal primary and secondary mirror baffles, the inside surface of the M603 tube has a series of five knife-edge baffles that help further in reducing scattered light and increasing contrast. Intes Micro has also taken pains with the moving mirror-focusing system, nearly eliminating annoying focus shift. The Intes Micro Maks are of the "Rumak" design, which uses a secondary mirror that is separate from the corrector, not just a silvered spot (as has been the case with all the MCTs we have looked at so far). Like an SCT, and in contrast to Questar, Synta, Celestron, and Meade MCTs, an M603 is easily collimated by the user. The robustness of the M603 does come at a slight disadvantage: This 6-incher's 14-inch long tube weighs in at a hefty 12.5 pounds. That is well within the payload capabilities of modest mounts, such as the Celestron CG5 and the Meade LXD75, however. Finally, in a real coup for the M603, it features an SCT-style rear port and can use many of the accessories developed for Schmidt Cassegrains. Like other Intes Micro scopes, the M603 is sold as a "bare" OTA, with the only accessories included being lens caps and a 50-mm finder.

The M603 sounds good otherwise, but is it too small in aperture? Check out the M809, an 8-inch aperture Mak. The M809 is nearly identical to the M603, but the standard package includes a couple of nice features lacking in the 603. Most important, there is a cooling fan mounted on the rear cell to speed thermal equilibration. A big Maksutov like this one must have help in this area if it is to deliver as advertised on nights when the outside and inside temperature differential is large. Like the M603, the M809 has a fairly large central obstruction, necessitated by its fast f/10 focal ratio. This obstruction will not appeal to the Mak purists looking for "APO refractor performance." For these cognoscenti, there is the M815, which is the same as the M809 except for an f/15 focal ratio and a smaller secondary obstruction (24%).

How about price? The over-7-inches point is the point at which MCTs begin to demand serious bucks. At $3,200 without a mount or eyepieces (the M809/815 do usually come with a 2-inch star diagonal in addition to a 50-mm finder), price is a consideration here, but the scope is hardly in the Questar price zone. $3,200 is not bad for a Mak of this quality and aperture, but remember to also allow for the cost of a suitable mount. At a weight of 21 pounds and a length of 21-inches, the M810/815 will need something in at least the Orion Atlas class, so be prepared to spend another $1,500 to get fully set up.

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