Comparison between 102achro, ed100apo, mak127 SkyWatcher

[Hardwarezone]

I had this ed100 scope and az4 mount on loan for a few weeks and thought about making it useful.
Unscientific simple comparison with phone camera on auto + 5 second timer , no dslr.
Non-tracking mount , no cooldown for scopes , no zenith.


Celestron Astromaster 102az achromat , 660mm focal length
SkyWatcher ed100 apo , 900mm FL
SkyWatcher 127 Maksutov , 1540mm FL with 1.25" mirror diagonal

The 102mm F6.5 achromat (Omni/StarSenseExplorer/PopSci) is very common in USA these recent few years for USD $199 with tripod.
Maksutov127 is a popular compact scope since around 2003 , my set is nearly 10year old with lower mirror reflectivity % as it degrade slowly every year.



Moon attempt #1
Phone camera doesn't sharp focus away from center , bigger maksutov image at disadvantage as closer to outer edge.
Photos are overlay onto each other to save horizontal width on internet forum.

ED100 and Maksutov127 used same 25mm eyepiece bundled free with ed100, eyepiece causes blue colour around the edge of Moon.
Maksutov unfair advantage by flock modification at primary and secondary baffles to improve contrast over normal factory set.
Green tinge due to phone camera coating when phone not perfectly center aligned as Moon drift across.

Moon attempt #2 possible thin clouds
15mm eyepiece , phone camera confused by small bright surface on 102achro


Moon attempt #3 thin clouds , picked 2 best photo from 48

[Hardwarezone]

Same 15mm eyepiece in all 3 telescopes.
Surprised the achromat background is warped , I never noticed this flaw at the eyepiece because the scope is portable and wide angle fun to use.


ED100 winner with more detail and clarity , used 5mm bundled eyepiece.
The mak127 + 9mm6mm Expanse clone were picked from batches of 10 photo each , to eyeball it focused sharp and not dim.
I did not test such magnification on the Moon, the Expanse clones 9 & 6mm have kidney bean blackout issue.

SkyWatcher evostar 100ed
Lens assembly 1.3kg , tube body with rings & dovetail 2.65kg = total 3.95 kg
Right-angle mirror 9x50 finder 475g , 2" diagonal 400g , 2"to1.25" 100g
OTA without 1.25" eyepiece = 4.925kg
Tube storage length requirement 89cm
Aluminium case empty 4.45kg

Skywatcher AZ4
Bare mount 5.15kg , aluminium tripod alone 2.725kg
triangle tray 450g , pan handle 300g
Total 5.9kg , with ed100 but no handle 10.6kg
Comes with dovetail L-bracket for mounting binocular or spotting scope with bottom 1/4" attachment.

[Hardwarezone]

Smooth movement with the mount head. Didn't test high magnification tracking.
When lifting whole mount with scope by hand , the top-heavy off-center balance put almost all the weight onto 1 arm.


The azimuth disk doesn't support to full diameter.
For attaching the mount head to tripod, I suggest left hand hold it hovering 2cm above and right hand screw upwards while look at 2cm gap.
Better than resting the mount head on tripod and doing it blind by feel. I had 1 attempt it didn't feel smooth due to misalignment.
Tripod connection is common m10 bolt Celestron cg4 or SkyWatcher eq3 , 6cm diameter x 2cm deep cup but the mount head only seat 4mm deep.



On first use , the tripod leg suddenly slipped by 3cm because I didn't tighten enough.
New idea to lay it on the floor , left hand tightly compress it and right hand knob gentle tighten with less risk of bite damage.
Use 2 hands to test compress each leg with few KG force leg doesn't retract at ant crawling speed before 1 hand hold the mount head from spinning and lift upright.


Center of balance for OTA is between the tray and tripod feet.
Tray doesn't rigid the spreader bars , only use the weight to reduce chance of tipover.


Did a test using these vibration suppression pads.
As expected they half the vibration time from 4 to 2 when I tap on the aluminium tripod.
During manual slewing , the moment my hands are off , smaller vibration disappeared leaving only the 2 big waves that transmit down & up the tripod legs.

[Hardwarezone]

Bought this phone clamp for cheap , metal eyepiece loop with plastic phone clamp.
Online is about $5 to $7 , I don't recommend this because the above eyepieces used are 14 to 20mm eye relief.
This clamp cannot raise the phone high or far enough , must clamp at rubber eyecup edge or rotating eyecup , nearly broke the eyecup.
It may function better with those short eye relief eyepiece with solid body.

Tried it on Jupiter after reduce shutter time and -4 exposure. With 15mm eyepiece.
Finally get 2 bands but different color than eyeball.



Bundled free case for ed100 is 85% length 78% height of 8" F6 reflector dob tube.
The 8inch dob design is #1 most recommended in USA, for Singapore I consider portability and low humidity storage.


The case is not airtight seal.
User should unscrew the lens cell and put into dry box or electronic dry cabinet with accessories.
To re-attach the lens cell onto the empty tube while vertical up , go counter-clockwise and wait for the "clack" sound when it drop off a cliff at the screw threads , then go clockwise.
Useful to place the lens temporarily in clean plastic container on floor while user handle the empty scope tube with 2 hands.
Don't be overconfident 1 hand lens 1 hand scope tube and walk around.
For longer term I suggest to penknife remove all cardboard inside the case and reattach the foam with small amount of $2 nano-tape,
may be possible to put rechargeable silica gel at the slot for finderscope for user to store and use the scope over a few nights without lens disassembly.


This plastic tub have silicone O-ring around the lid 4 sides for airtight seal. The white tube device is rechargeable silica gel.

The ed100's bundled 5mm eyepiece (180x mag) gives a bright scattered light around Jupiter, takes effort to move eyeball around and find it , not suitable for outreach.
AZ4 mount is fine for looking at zenith at low magnification with 32mm plossl.

[akdwivedi]

interesting.. I had a different experience. The ED100 f/9 doublet have such good views of jupiter/saturn and moon that I was tempted to upgrade to sw120ed. but I havent tried the 5mm bundled eyepiece. I use a 10mm UFF or celestron 8-24mm zoom most of the time and with them the views are excellent.

[Hardwarezone]

The bundled 25mm was the culprit for the color fringe , as shown in Moon attempt #1. It's gone when I changed eyepiece for #2 #3
Extra effort to setup 3 scopes before sunset and the clouds float in at 7:40pm.
Carry the scopes 1-by-1 to staircase to take photo within 1 hour.
After moving this top-heavy setup I didn't want to repeat the same routine over the next few days. Disassembly takes effort too.

Different from convenient access to zenith and not limited by a few days of opportunity.

I can delete the blurry photo of #1 #2 if deemed misleading.

[akdwivedi]

very nice comparison. I think the ed100 doublet is fantastic scope. though I also loved the orion 120ST. despite being an achromat, it was a fun scope, fast at f/5, short and easily to grab and setup. but I had better views through the ed100 doublet of the luna.

I have pondered a number of times about the mak127.. its such a nice scope specially for planetary views, but I have a C5 and C6 so I am not allowed to have another scope in the same aperture class.