Much has been said about Maksutov-Newtonian telescopes in recent years. Like any fine, new design, things get tested, discussed, coveted, etc. The Ceravolo Mak-Newts have become the stuff of legends. They have a reputation as being some of the very finest in telescopes featuring hand polished optics which stand up to high-end refractors of the same aperture.

Two years ago, I ordered a Ceravolo f/6.5 HD-145. Ceravolo no longer makes the f/4.5 photo-only model, which is fine by me. The f/6 version allows for a 2"/pixel ratio on my CCD imager which is optimum. The wait time was, in theory, 9 to 12 months. Well, it took a bit longer than that (It took just shy of 2 years). Peter Ceravolo was honest and said that he would indeed tax my patience but would provide the finest optics available.

The OTA shipment arrived faster than fast. There was a brief email exchange on a Wednesday to discuss shipping address, and the tube was delivered Friday afternoon! That is fast for UPS. It was well packaged in a cardboard assembly with a lot of well-fitted foam. In a separate box was the dew shield and a 2" drawtube. The scope already had its mounting rings attached. Everything arrived in fine condition: no bumps, no bruises.

The OTA's mount rings were then attached to a Losmandy universal dovetail plate so that it could be mounted on a G-8. The rings on the HD-145 were already threaded to accept the Losmandy standard thread. My G-8 has been modified to accept the G-11 sized plates so that all my scopes fit the two mounts (G-11 and G-8). Once on the mount, a thorough inspection was done.

The tube is a glossy black with a textured paint job. The dust cap is a screw-on variety which is easy to handle and made out of metal. The dew shield also acts as a stray light shield and screws onto the same threads as the dust cap. Both fit very well.

The focuser is a quick-thread type with two interchangeable drawtubes. One is for 1.25" eyepieces, while the other is a 2" drawtube. One must change drawtubes whenever changing eyepiece sizes. This can be remedied by just using a 2"-1.25" adapter. Changing eyepieces and drawtubes creates a deep sounding "thrumb" from within the tube indicating an airtight assembly. A brass screw locks the focuser mechanism, while smaller red-plastic capped screws lock the eyepiece and drawtube into place. The focuser worked well at night. I got along well with it, which was relieving, since I usually use SCT focusers and Crayfords. Stars were easily brought to sharp focus in no time at all.

Opening the dust cover reveals the Maksutov corrector or meniscus lens. This is a real beauty. The lens is multicoated (it is available as an option, though I do not know anyone who would not want the coating!) and shows no reflections without really trying. The images below show that the secondary is mounted right onto the meniscus and is permanent. There are no user-adjustable parts here. In theory, one never needs to worry about collimation of the secondary. Ok! Fine by me.

For those interested in optical theory: Why a Mak-Newt? Well, why a Mak? The meniscus lens is a corrector for spherical aberration caused by the spherical primary. Spherical primaries are easier to make and are easier to make well.

First Light was very informative. The scope was aimed at a variety of stars which showed heat plumes rising through the optical assembly. The scope had already been outside all afternoon, but the night was considerably cooler. About two hours later, the scope had settled down, but local seeing conditions were far from ideal. I was able to look at the whole of the North American Nebula with a 55mm TeleVue Plossl. The stars were pinpoints across the field. The Ring Nebula looked fine with a 10mm Radian, but the real fun started when a 3mm Radian was used. The Ring Nebula showed detail throughout its donut shape. The two stars nearby (magnitudes 12.5 and 13.1) were clearly visible and surrounded by inky darkness. The contrast was very good.

Moving along, I aimed at the Andromeda Galaxy. It was nearly overhead now and well placed. The 55mm Plossl showed the whole extent of the galaxy and its two neighboring galaxies as well. Details were evident in the M-31 dust lanes and outer arms. It was a thrilling view. Saturn was rising, so that became the next target. Again, going from a 10mm to a 7mm to a 3mm never hurt the image capability of the telescope. Seeing conditions rarely allowed the 3mm to really show off. The Cassinni Division was plainly evident as were bands on the planet. Color was fine and pure. No hint of the blues seen in achromatic refractors.

Star testing was done using Vega and Altair. Both may have been too bright, and seeing conditions were not optimal as stated before. Outside of focus, the rings were sharp and bright with good contrast and perfectly in center. The small dark hole of the secondary was a pleasant change from the usually large gaping hole presented by SCTs. When the star was brought into focus, there was no doubt. The Airy disk was pure and round with one and sometimes two diffraction rings around it. They were identical in size, thickness and brightness ratio. Aiming the scope at the double-double, Epsilon Lyrae, was a joy. The star was completely split as expected. Using a 3mm Radian eyepiece, all stars showed their Airy disks and the blackness of space separated them. Contrast was lovely. I don't know how many commercial 8" SCTs I have looked through that could produce such a great view... not many. Looking at Albireo (Beta Cyg) was just as pleasurable: the two stars were sharp and contrasty, and their colors were plainly visible.

Last Modified: 3/19/03 8:55p
This page:© Copyright 2005 by John A. Blackwell