Posts Made By: Philip Canard

I called up Harry to talk about his Observatory EP's, specifically the 40mm FL. He let me know right off that there would probably be image cutoff issues in my LOMO 150 Mak-Cass using the Stellarvue dielectric diagonal. He offered to custom make me a 38mm version instead of stepping all the way down to the 36mm FL. No extra charge for the special FL, so I ordered and waited. Several weeks later it arrived. It had the standard Siebert machined turned finish on the outer body. Interior had very rough black paint similar to what LOMO scopes use that Harry says "sucks light". There are six set screws visible on the exterior that obviously lock things in place. I now have 9 Siebert EP's, and not a single one has ever developed a rattle, like Japanese and Chinese EP's often do. They all come in a bolt case for protection.

I noticed some image cutoff in my LOMO 150 and Stellarvue NH II, both with my 2" Stellarvue dielectric diagonal. Pulling out the diagonal and looking through the EP revealed that the nosepiece was indeed cutting off the image edges a bit. A 34mm Axiom has no problem, and neither does a 50mm Axiom. The 38mm Observatory must therefore be quite wide in true FOV. With no scope available that can use the whole FOV, I can't do a star drift to determine the true FOV. I'll have to take Harry's word, whatever that was, until I can do a test. It's a wide FOV, but not a Nagler by any means. Definitely in the Axiom or Panoptic class.

If you use the Stellarvue 2" dielectric diagonal or equivalent, get the 36mm Observatory as it's all you can use. Also, the EP is quite light for such a wideangle 2" EP. It doesn't overpower the NH II on the Grab-n-Go mount as a Nagler would. Harry states 9 oz., but I did not weigh it. It is all aluminum, except for glass and rubber/plastic eyecups. The eyecups are a bit strange, as it is a nested design. Eyeglass wearers will pull out the central nested rubber eyecup to get a full FOV. I leave in the rubber eyecup to cut down on glare when I observe in town. The large primary eyecup is hard plastic, except for the central part that would touch your glasses, which is rubber. The nested eyecup is a friction fit of rubber against rubber. Looking down from the top, the EP is all black, what isn't glass. There's a lot of glass there to look at. The bright natural aluminum body makes it easy to locate at night, I have found out. Coating reflections are the normal Siebert yellow and blue colors. Color balance of images seem fairly neutral. At least no major color shifts have been noticed compared to my Ultimas and Axioms.

This is, obviously, a deep sky type of EP. Viewing very bright objects like Jupiter reveal more glare and reflections than an Ultima or even an Axiom, for instance. Harry's own Star Splitter planetary series deliver a blacker background and less light scatter. A lot of the problem will be stray light shining on the EP or reflected from your face, so an observing hood of some type has been necessary for me when observing in town at night. I leave the nested eyecup in place when observing in town to help shield the eye lens from glare. Fine detail is quite good, similar to what you would get from an Axiom in my scopes. Edge sharpness could be better in fast scopes. Rectilinear distortion is quite low, similar to an Ultima, so terrestrial observing is quite good. I get no image cutoff with my 34mm Axiom in my diagonal and scopes; therefore, I genberally use it more often in astronomical observing. Size is very similar between the two. Eye lens is slightly bigger in the 38mm Observatory. Field stop is slightly bigger in the 38mm Observatory, but the objective lens is a bit smaller. 34mm Axiom is slightly heavier, as it is brass barrelled. 34mm Axiom cost me less, as I got it on a closeout, but normally runs $40 higher at regular street prices. The multi-colored coatings of the Axiom tend to work a bit better, I would say.

The comfort factor is about equal for both EP's. Kidney beaning and blackouts have not been an issue in the 38mm Observatory. If you need a lightweight 2" EP to max out the FOV and light gathering ability of your scope, can't afford a Panoptic 35mm or 41mm or don't want their size and weight, then the Siebert Observatory Series is a viable alternative. Used 34mm and 40mm Axioms sometimes come up for sale and are great bargains when they do, but since being discontinued they are getting harder to find brand new. Observatory Series are not available under about 30mm in FL, so basically you pick the one that maxes out the FOV and/or exit pupil size in your scope. They will cause less of a balance issue than long FL Pans or Naglers in Dobs and smaller refractors. There is basically a nonexistent used market as far as Siebert Observatory EP's go right now, so you had better plan on spending the $199 for a new one if you want one, but Harry gives a money back guarantee and at least a 60-day trial period. The trial period is rather generous as it is unlikely you will want to return it after getting used to it. It's not a Pan or Nagler, but it has it's own charms, besides the much lower price.

Don't put much faith in my personal observations if you're wanting to try one. Since there's a money back guarantee, I would buy and try for most of the trial period and see if I liked it if I needed a 2" EP of the wideangle variety. Like a Rickenbacker guitar, it's a bit of a strange duck, with a finish nobody else uses, but Siebert Optics has it's legion of dedicated followers. It also has its critics on the other astronomy website that seems to have an anti-Siebert bias. Most of the Excelsis reviews are positive, except for one guy that had an axe to grind, it seems. If a Siebert EP of mine ever falls apart, I'll let you know, but so far no rattles and no major complaints. If you want the last bit of performance, ante up and get a Tele Vue or whatever at 2 or 3 times the price. If you like to kick back under the stars and see a lot of things without breaking the bank, then this is a good place to start your funky Siebert EP collection. You too can join the ranks of "Siebert Barbarians" with naked EP's and more party money for barbecue and beer this summer than your Pan and Nagler toting astrogeek acquaintances.

Phil

P.S.

The Observatory Series has a strong paint smell, obviously from the interior coating, when you first get it. After several days of use, it largely goes away. These do not sit on dealer shelves for months or even years as some EP's do and thus have no chance to air out in the box and the plastic bolt case prevents much off gassing anyway. As soon as it's built, it's on the way to you and will have that "new aroma" much like new cars do. Just another idiosyncracy you get used to with Siebert EP's.

They are an upgraded version with better prism mounts than the generic version of the Chinese BV as sold by everybody else.

Harry Siebert will upgrade the generic Chinese binoviewer with better mounts. The downfall of the generic version was the ease with which it lost collimation due to the prism mounts. Baader fixed that problem as well in the Maxbright.

You might consider paying a little bit more and getting the nicer Siebert Black Night 22 binoviewer. They don't get the praise they deserve, and $300 is the biggest bargain in the BV field. Its basically an improved BW Optik that sells elsewhere for up to $800. APM sells the BW Optik for $475 last time I checked. By the time you add a Siebert OCA, the total cost will be no more than going with Baader BV + Baader OCA. The BN22 is also lighter as well as being tougher and better collimated. The Baader Newtonian OCA is considerably bigger and heavier than the 1.8X Siebert Maxlite OCA. Harry Siebert just told me he had upgraded the diopter adjustment on the BN22 and lowered the price of that option. I never felt the need for diopter adjustment, as it's just another thing that creeps out of adjustment when I had my Chinese binoviewer. Diopter adjustment is quick and easy with the self centering EP holders of the Siebert BN22 anyway.

I bought an NGF-55 two-speed focuser for my SN-8. Meade saw fit to include plastic junk with the OTA and it was ruining my observing. The JMI NGF-55 was a drop-in replacement. It cost $300 delivered with the fine focusing option. It has worked reasonably well. A couple of problems: the website photo showed dual thumbscrews on the drawtube to hold the EP, but the focuser only comes with one now. The inside of the drawtube and extension tube are shiny smooth black anodized aluminum with no filter threads on the extension tube. Had to paint the inside of the extension tube and have it threaded. This focuser sits about 3/4" lower than the stock unit. With extension tube installed, I have to raise a 2" Axiom EP up a bit to bring it to focus. It's OK with 1.25" EP's, and too fast an OTA to use most 2" EP's without a Powermate anyway. The supplied thumbscrews for the extension tube have dimpled ends that will mar an EP barrel, since the extension tube has no compression ring like the drawtube has. The reducer has a single thumbscrew and compression ring to protect 1.25" EP's.

I use a Baader Click Lock with 2" nosepiece to hold my 1.25" EP's and binoviewer anyway. It's much better than the JMI extension tube with JMI 1.25" reducer. The focuser comes standard with the extension tube and reducer, so cannot leave it off for credit. You may need a longer extension tube than standard if you intend on using 2" EP's with the focuser. It seems to be optimized for camera use, which is no surprise as the SN-8 is an astrograph OTA. I'm going to mount some cameras after my move anyway.

Anybody else getting a JMI focuser for a Newtonian might want to check out the issues with internal threading and blackening of the tubes. Also, remember the lack of compression ring in the extension tube.

The nice thing: there is plenty of infocus for me to use my binoviewer with simple Barlow type cell at the front of the bino. No intrusion into the OTA at closest focus like the stock unit. The 10:1 fine focus option works quite well at high powers. No flopping and bending out of collimation with heavy binoviewer. It should hold any reasonable sized camera up to a full size pro 35mm SLR like a Nikon F2 or Canon DSLR with no problem. Electric focusing with digital readout is an additional option. The SN-8 is performing to its optical limits now. Have had no need to adjust the focuser tension, in fact JMI warns against doing that. This is the type focuser that Meade should have included with the SN-8 and SN-10 OTA's.

good luck,
Phil

I noticed there was a question on the Tele-Vue Para-Corr. A person might want to consider the much less expensive Baader MPCC that is configured for visual or photo use in f/4 to f/6 reflectors by making use of various T-2 system accessories. The T-2 mount allows use with all but the largest 2" EP's that have field stops bigger than T-2 size.

A simple $20 T-ring adapter allows use with a 35mm SLR camera. You screw it onto a T-2 Click-Lock for use with 1.25" EP's. It screws directly onto 2" EP's. VArious T-2 extenders give the right insertion optical length for 1.25" EP's. Usually a 15mm extender between MPCC And Click-Lock.

Phil

Decided to play around with the binoviewer, and discovered a couple of neat things about them.

First, you need to take out the OCA and EP's to try these first two tricks.

Looking through the front of the binoviewer, you will see double images as if you were drunk. Spinning the binoviewer around will make the images spin around each other. Kids love this trick. Varying the interpupillary distance changes the separation of the double images a bit.

Looking through the eyepiece end, you can put the front end againt a keyhole or other small opening and spy with both eyes open. Beats wearing an eyepatch when spying. On a practical level, you could attach an inspection camera to the input of the binoviewer and inspect internal spaces more comfortably.

On a practical level, you can put a different color filter on each eyepiece (red and blue or read and green) and increase the 3D effect of lunar and planetary observations.

You can also put a nebula filter on one EP and none on the other and blink the eye behind the EP with no filter. Planetary nebulae will stay turned on while other flare in the EP will turn off.

You can put two different EP's in the binoviewer and quickly change the magnification and angle of view without buying an EP turret....or really give yourself a headache if looking through both EP's at once.

The weather forecast predicted a low of 35 degrees Fahrenheit tonight. By the time the temperature had dropped to around 45 Fahrenheit, my Orion green laser pointer had quit working at full output. It got dimmer as the temperature dropped. It started working again when I brought it inside the house and warmed it up.

Orion did not list an operating temperature range in the product literature. I did a quick search, and found that most green lasers had a lower temp operating limit of around 10 degrees Celsius, which is 50 degrees Fahrenheit.

I guess this means that the Orion green laser pointer is about as useless as the Meade Autostar hand controler display when temperatures are below 10 degrees Celsius, which is about half the year for night time low temperatures around here.

Consider the low temp limit before you buy a green laser pointer if you live in a cold climate where you frequently observe below 10 degrees Celsius (50 degrees Fahrenheit).

Phil

I discovered this UK CAT scope design while I was surfing the UK astronomy dealer websites. Anybody ever look through one?

http://www.capenewise.co.uk/

When the company compared it against other competing scope designs, I see that they wisely chose not to compare it against the Russian Maksutov-Newtonian which is optically simpler and accomplishes basically the same thing. The Mak-Newt has only 4 air-to-glass surfaces vs. the 8 air-to-glass surfaces of this UK design.

Also, my Meade SN8 with Baader MPCC should accomplish basically the same thing at a faster f/4 focal ratio and with two less optical surfaces to scatter light.

I think I would opt for an Intes-Micro MN86 myself, or an MN84 if I was astrophoto inclined. Just about every positive attribute of the Cape Newise scope could be applied to the Mak-Newt in my opinion, and the Mak-Newt has a few things over it such as fewer optical surfaces. There is no way this Cape Newise design with 4 extra air-glass optical surfaces can be as "refractor like" as a good Mak-Newt. Maybe that's why it never took off in North America? The prices seem OK relative to a Mak-Newt, but I never read a Cape Newise review. There are 8 UK dealers listed, so I guess Cape Instruments is selling a few units now and then. Intes-Micro probably isn't exactly soaked in a cold sweat over this design, however. The TAL 200K KCT with focal reducer should do as well and be more compact.

The Cape Newise scope looks like something for Ye Olde Scope Shoppe to sell to somebody simply wanting something different and British. A bit more compact and lighter than a Mak-Newt, but that's about all I can see it has as technical advantages. What thinks ye?

Phil

I just got a new 2" Siebert Power Mag Wheel today. I'm going to be socked in with bad weather through the weekend, so no use to try it on the fast Newt. I pulled out my 80mm f/6 Nighthawk II and did a preliminary test for terrestrial use.

The input side is a 1.25" tube about 2" long. The body is the standard 3-mag body that Siebert makes. This model is Telecentric in operation, so the output side is much bigger than the input side and and has about 38mm output lens and a 2" eyepiece holder barrel. Included was a 1.25" eyepiece adapter made of Delrin. The output lens is what I would call a T-2 size. It will not illuminate the field stop of the longest 2" EP's. Still, it works rather well. It is a 2X, 3X and 4X mag model.

With a 38mm Siebert Observatory, there is some reduction in AFOV due to slightly small output lens, but the field edge was still fairly sharp. At all mags the view was sharp to the edge, and no refocusing was necessary when going from center to edge. Harry said this model should eliminate the need for a Para-Corr in a fast Newt. When going from 2X to 3X to 4X, you must refocus a bit. The biggest jump is between 2X and 4X and amounts to less than 1/2" in my NH II. The 38mm Observatory is an EP that maximizes the AFOV in a 2" barrel. It vignettes a bit when placed in many 2" diagonals due to the nosepiece of the diagonal cutting off the light cone a bit. Still, a full 2" output lens would solve that problem in the PMW. Your 41mm Pan or 31mm Nagler will have the same issues.

With a 26mm 2" E-Lux Kellner, an EP that gives horrible results when used alone in the NH II, the view was very useable at 2X, and got better from 3X to 4X. At 2X it was a bit soft on edge, but no refocusing was necessary to get the best sharpness. Edge sharpness improved noticeably at 3X and was about the same at 4X. The entire AFOV was preserved in the 26mm E-Lux and the field stop was razor sharp. It would seem to indicate that the PMW flattens the field appreciably in the NH II.

The last EP I tried was a 15mm Axiom in order to get an idea of the performance with a 1.25" EP. It performed well at all mags and had a flat field that needed no refocusing when scanning from center to edge.

The weather was rainy so I could not ascertain how it handled a high glare situation. Antireflection coatings reflect yellow, pink, purple and blue colors. I noticed no problems with backlighting from the sky when looking up at dark pine leaves and cones in a tree across the street.

The magnifications seem close to what Harry said they would be. One oversight was that the input was not threaded for 1.25" filters. That is no problem in my case as my focuser is threaded for 2" filters. The smooth input barrel allows me to move the PMW up or down at least an inch and lock it in place with my Baader Click-Lock holder on my f/4 Newt. When used in a prime focus mode with a camera, the f ratio will be f/8, f/12 and f/16.

The optical performance seems promising so far, and when you consider that it can eliminate the need for a Para-Corr and allow you to use really long focal lengths like a 55mm Plossl with my f/4 Newt, then I believe this could be a useful accessory. It costs a bit more than a 2" Powermate, but it does have 3 times the mag settings available at the push of your thumb and a quick refocus. What I like is the way it makes cheap EP's perfrom in a fast focal ratio scope. There is no need to go down to short focal length EP's with squinty little eye lenses. Harry said I got the first one he made like this, so if there is an interest I will report how it works in the f/4 Newt after the weather clears. I already know I will be using it in the refractor for terrestrial viewing.

If you want to use big, comfortable and cheap 2" EP's in a fast focal ratio scope and need a mag changer for your camera, consider getting a Power Mag Wheel.

Phil

If you want viewing comfort and a big eye lens, it would be hard to beat the Baader Hyperion series. You can extend up from there with a 2" UO Mk70 in 32mm, an Axiom 34mm or Siebert 34mm Observatory. Your M603 isn't going to support a 40mm wideangle most likely and I happen to know that a 34mm Axiom maxes out the FOV in my 6" Russian Mak without image cutoff. The Baader Hyperions are best used as 2" EP's in a 2" diagonal.

OK, no secret that a high quality Mak scope is a glutton for high magnification on a night of good seeing. My LOMO 150mm Mak-Cass will support 511X calculated with a 4.4mm Star Splitter and still give good resolution and contrast on lunar views. That is well over 3X the aperture in MM. What have you been able to achieve with YOUR Mak scope as far as high mag limits go?