Instruments*

 

Updated as of: 05.19.2009

 

My observing environment has changed from nightly equipment moves to the end of the driveway into an observatory and fixed pier system at New Mexico Skies. Prior to this move however, I needed to move equipment, re-setup and re-align every night. There are 5 major sections below covering Mounts, Optics, Supports, CCD's, and Others. I have used the following major platforms: [for observatory dome information click here]:

As of April, 2009: RCOS 20"<Paramount ME Mount<Fixed Pier in Dome

Takahashi FRC300 + Televue NP101 < Paramount ME Mount < Particle Wave Monolith Portable Pier

Takahashi TOA130 < Takahashi NJP Mount < Takahashi Wooden Tripod

Takahashi FSQ106N < Takahashi EM-11 Mount < Takahashi Wooden Tripod

Takahashi Sky90 < Takahashi EM-11 Mount < Takahashi Wooden Tripod

Meade 14" SCT < Paramount ME Mount < Particle Wave Monolith Portable Pier [OTA Sold]

Meade 14" SCT < Meade LX200GPS Fork Mount < Meade Giant Field Tripod ... [All Sold]

Here are my observations regarding Mounts that I have used:

I am not a big fan of Meade products as I experienced defects with new equipment. In my opinion they are generally of lower quality even at the upper end of the product line. The mount was very difficult to align, not accurate, too heavy and cumbersome to use. On the other hand, I have only good things to say about the Takahashi NJP. It has worked perfectly in every respect. The Paramount ME will carry a heavier load than the NJP, and after employing PEC software it is essentially equally as accurate as the NJP.

I have recently modified my opinions regarding the use of the Paramount in a nightly portable situation (movement to the end of the driveway). I have proven to myself that the ME is the preferred mount for me in a fixed pier, observatory location. After one year of learning, mostly through trial and error, I became equally comfortable using the ME or the NJP in my nightly driveway rollouts. My slow learning curve with the ME was complicated by the longer focal length of its OTA vs the NJP. This required precise physical positioning each night such that the ME will have essentially the same performance characteristics as if it were on a fixed pier. I have now mastered this task.

I can now equally recommend both mounts for a portable situation similar to mine.

Mounts

Meade LX200GPS - sold

Takahashi NJP

Takahashi EM-11

Paramount ME

Ease of daily setup and a good polar alignment

Very time consuming >40 minutes. Most Difficult to get right.

Fast and easy! The Polar alignment scope is great! I can normally be within 30 arcseconds of perfect alignment in just 10-15 minutes. The job is simplified by the shorter FL of the TAK TOA130. View Sample.

I bought this mount for traveling. It includes a built in Polar alignment telescope which like the NJP mount makes if fast and easy to use.

The biggest drawback with the ME was that I had a steep learning curve for fast polar alignment in a roll-out environment. View Sample. While not approved by anyone, I have finally found a setup procedure that gets me going as fast or even faster than the NJP setup in a roll out environment. See my Paramount quick-alignment blog.

Rank [roll-out] 4 1-tied 3 1-tied
Rank [fixed pier] NA 2 NA 1
Use with a remotely controlled observatory I would not want to try it. Probably would not work well or at all. Probably would not work well or at all. Excellent, and perhaps the only really good choice.
Polaris required to be visible for alignment Yes, if using Autostar alignment. Yes, if using the polar alignment scope. Yes, if using the polar alignment scope. No, a big advantage in flexibility for the ME.

Portability/weight

Awkward and heavy - the worst with its combined fork and mount.

Heavy but compact and luggable ~50lbs

Much lighter and more portable than my other mounts.

~20 lbs

Most heavy, ~65lbs before weights and not easily moveable without wheels.

Pointing Accuracy.

Worst. I could never really get it to be really accurate. I found and repaired drive gear damages.

Outstanding accuracy. It works even better with TPoint.

 

 

I have a USD-3 model upgraded to Temma 2 encoders. Overall the pointing accuracy is excellent. however see the other points below.

 

 

 

Pointing accuracy is excellent after a good TPoint model is available with over 200 points.

Tracking Accuracy

(Uncorrected)

Worst, published tests show 15.0 arcseconds of error.  I found drive gear damages on my system.

Uncorrected peak-to-peak error measured at 2.3 arcseconds using 5th order fitting with PemPro. This is better than the advertised error of 4 arcseconds. View details.

I have not measured the tracking accuracy. However, manual observations indicate peak error at about 2x that of the NJP.

Over six Worm Cycles yields an uncorrected 5.7 arcseconds of error using cubic drift fitting. A little worse than the advertised spec of <= 5.0 arcseconds. View details.

Tracking Accuracy

(Corrected)

Worst, published test show 5.0 arcseconds of error after software corrections.

TAK does not provide for software error correction, so 2.3 arcseconds of error remains.

TAK does not provide for software error correction.

Measured at 0.8 arcseconds, View Details which is outstanding given that some of the error is from atmospherics, and it is less than .5a.s. in either X,Y direction. Error measurements and corrections made with PemPro.

Tracking Accuracy (Corrected and Guided)

Unknown Usually < 0.3 pixels (X+Y) with 1000mmFL; and <0.1 pixels in RA using a 540mmFL remote guiding telescope I have not measured the tracking accuracy. However, manual observations indicate peak error at about 2x that of the NJP.

Using a well aligned, fixed pier averages < .3 pixels combined (X+Y) error using a 540mmFL remote guiding telescope.

Functionality

Hand Controller or PC- with fully competitive capabilities

Hand Paddle or Via Sky6 and limited options compared with others. No PEC

Hand Paddle and limited options compared with others. No PEC

Joystick or Via Sky6. Rich functionality, PPEC, ProTrack and much more.

Complexity

Average

Low

Low

High

Approx. Load Limits

75lbs

70lbs

20lbs

150lbs

Documentation

Good, Complete

Very weak, limited in English (But complexity and functionality are low, so it is not as necessary)

Very weak, limited in English (But complexity and functionality are low, so it is not as necessary)

Excellent, Comprehensive

Other Points

I would only recommend Meade if you are on a tight budget.

Other than the long delivery lead times for telescopes (see OTA's below), I have been very satisfied with everything carrying the Takahashi label.

I have experienced pointing go-to errors with the EM11. The problem was diagnosed and corrected as a loose locking screw on the RA encoder-shaft.

Software Bisque the manufacturer of the Paramount ME also develops and/or licenses an outstanding suite of software for astronomy. I highly recommend Sky6, CCDSoft, T-Point and other associated products.

Availability Immediate 1 month Immediate 2 months


Here are my observations regarding Optics:

There is really no comparison. Takahashi is vastly superior to Meade and better than others that I have used, IMHO. TeleVue is also very good. For larger apertures and longer focal lengths I have found that RCOS telescopes are the best instruments for me.

Optical Tube Assemblies

Meade 14"

Schmidt-Cassegrain

Takahashi

TOA130 Refractor

Takahashi FSQ106N Refractor

Takahashi FRC-300 Ritchey-Chretien (See a full review)

RCOS 20" Ritchey-Chretien

Overall Average Great Outstanding Outstanding Outstanding
Image Quality Average Excellent Superb Spectacular Spectacular
Rank 5 4 3 2 1

Aperture

356mm

130mm

106mm 300mm 508mm

Focal Length

3560mm

1000mm

530mm 2348mm 4115mm

Focal ratio/w reducer

f10 / f6.3

f7.6 / f5.76

f5.0 f7.83 / f5.9 f8.1
1st Light 2/2005 5/2005 12/2006 6/2006 4/2009

Quality of the optics

Average

Great

Excellent Excellent Excellent
Focuser Primary Mirror 4" Rack&Pinion

2.5" Rack&Pinion

Helical

Servo motor on Secondary Mirror

Ease of Focus

Difficult, needs continual refocusing

Good, Easy

Normal Very Easy - Do it once and lock it in! Then detail focus with FLI-PDF Very Easy - After a correct Backfocus distance is physically set, focus is controlled directly with TCC or FocusMax
Back Focus unk 256mm 120mm 106.2mm 381mm

Spot free internals

Good

I expected better - only good

Clean Clean Purchased Used and dirty
Cooling and Heating None Included None Included None Included None Included 3 tube air fans with dew heaters included
Instrument Rotation None - not needed None - not needed None - not needed None - not needed An Optional Add-on, but very necessary
Temperature adjustments None None None Automatic within 5degC [refocus 2-4 nightly] Carbon Fiber (Very Stable Focus) [refocus 1 nightly]

Mirror

Locks Manually -

This is a big problem as the OTA continues to lose focus with movement or with temperature changes

NA

NA Fully Locked, no flops Fully Locked, no flops
Obstruction Yes, but unspecified None None 25% 16%
Weight of OTA Unknown 22 lbs 15 lbs 66 lbs 160 lbs
Best Usage Galaxies and deep sky Nebulae, Planets Wide Field, and Nebulae Galaxies and Nebulae Galaxies and deep sky
Availability Immediate Immediate Over 1 year 7 months 3 months

Here are my observations regarding the Support Systems:

Tripods and Portable Piers Mead - Sold Takahashi Monolith Fixed Pier in Dome
Stability Poor Excellent Outstanding Completely Solid
Rank 4 3 2 1
Portability/Weight Heavy but easy to breakdown Lighter Weight but more effort needed to breakdown At about 50lbs, it is not particularly well suited for portability. Works fine with wheels. Not meant to be portable
Approx. Load Limits 200lbs 155lbs 2,500lbs 5,000+lbs
Materials Aluminum Wood Aircraft quality Aluminum Steel
Availability Immediate Immediate 6 months Custom Made 1-2 months

 

CCD Cameras:

My CCD manufacturer of choice is Finger Lakes Instruments (FLI). See my review comparing the FLI ProLine09000 and the SBIG STL11000 here, and see my comments below:

Camera SBIG ST2000XM SBIG STL11000M Starlight Xpress Lodestar Autoguider FLI ProLine 09000
CCD Sensor Kodak KAI-2000 Kodak KAI-11000 [Class-1] Sony Exview [Class-1] Kodak KAF-09000
Rank 4 3 2 1
My comments Internals were not clean on delivery.

Clean internals, but in my opinion my chip appears to have too much unwanted noise. SBIG responded that this is pretty normal. These apparent artifacts of the read out process can show up in images after reductions and I use Photoshop spot healing to eliminate the lines in the final images. This is not what I expected from this camera.

When I wanted to improve my CCD, I ordered the FLI ProLine in part because of my disappointment with SBIG's response to my concerns.

This Camera is designed to be an autoguider. With a low weight of only 50g (1/10 lb) it provides excellent capabilities without adding weight to the camera train and mount. It is a great companion to an FLI camera which has no internal autoguiding capability.

My experience to date with this camera (placed in live operations in May, 2009) has been excellent. Connected to an OAG mirror, there has been no noticeable flexure. The electronics have worked as advertised, and the lack of cooling has not caused any problems.

With its very modest chip size, accurate pointing from the mount and telescope is mandatory with longer focal length telescopes. For the same reason, the guide stars and Position Angles must be manually selected within the planning software before imaging. In my environment, the field of view is too limited to have the guiding software select its own guide star automatically.

I love this camera.

Before I received my new FLI CCD, Greg was very helpful by sending me a copy of the CCD's Bias image taken in the FLI lab. Now these are different chips, with Bias's taken at differing temperatures, etc, etc... but even with all the caveats the FLI Bias looks to me to have less noise and less concentrated noise than that from my SBIG. Most of this noise reduction is probably a result of the lower temperatures that I can achieve with the FLI cooling system, in my opinion.

FLI has met or exceeded all of my expectations. Operational temperatures are reduced by nearly 60deg C from ambient. The chip's QE superiority and lower read noise are noticeable in my opinion. Downloading at 12 MHz is fast and almost fully noise free.

Max Air Cooling 30 deg C 30 deg C none 55-60 deg C

Actual Cooling achieved: Ambient/Operational

+28/-5 C +28/-5 C none +28/-30 C

Bias Images [at my normal usage cooling temperatures] The images shown are illustrative only and are stretched .JPG

at -9C at -10C not used at -25C
Approx download time for one Bin 1x1 image 15 seconds 20 seconds 2/10 Second with USB 2.0

2-3 seconds at high speed

15 seconds at low speed (min noise)
Chip size

13.38 x 9.52mm

1640 x 1214 pixels

37.25 x 25.70mm

4008 x 2672 pixels

6.4 x 4.75mm

752 x 580 pixels

38.6 x 37.76mm

3103 x 3086 pixels

No of Pixels 1.9 MP 10.8 MP .4 MP 9.0 MP
Pixel size 7.4 µm 9.0 µm 8.2x8.4 µm 12 µm
Architecture Interline Interline Interline Full Frame
Saturation 40 K 60 K 50 K 120 K
Read Noise 13.5 e 13 e 10-15 e 7 e
Peak QE 45% 50% 65% 69%
Self-guiding Yes (Internal) Yes (Internal or optionally external) NA No
Max Shutter Speed .001 Seconds .001 Seconds No mechanical shutter .01 Seconds
Dark Current Doubling Temperature 7 deg C 7 deg C NA 7 deg C
Availability < 1 Month <2 Months about 1 month ~ 5 Months

 

Summary Recommendations:

In my opinion Takahashi is usually superior to the other products that I have used. It is expensive, and it is just plain good. I am equally pleased with the RCOS telescope. I am completely pleased with the Paramount ME and Takahashi NJP mounts. I strongly prefer Finger Lakes Instruments ProLine CCD with the Kodak 09000 chip over the SBIG options.

Other equipment recommendations (all excellent products):

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Other software recommendations:

PEMPro: (Return to Tracking section)

I have switched from PrecisionPEC to PEMPro for measuring and building PEC error correction tables for the ME's firmware. It is an excellent and comprehensive product.

 

*Legal disclaimer:
The preceding equipment analysis and recommendation are based solely on my opinions and judgment. The recommendations are not based upon scientific, demonstrable or documented evidence. So don't sue me just because you might not like my opinion.