637 replies to this topic

[Eric H]

 

Here's the new 152 and me.

What an amazing set up!  How tall are you???  Do you find you are having to view in uncomfortable position when viewing near zenith?  While I am not sure which 6" APO I will get, I do know that one will come sometime in the future!

 

I'm 5'-11". Haven't had the chance to view with it yet. Clouds!

Don't think I'll have too much trouble with viewing position. My Tripod extends quite a bit more than in photo.

[drd715]

Well the 152 is here. Just opened the box and 99% perfect (only because 100% is unattainable). Will have a more in depth inspection over the weekend, may be set up the mount for test. 3.7 inch focuser amazing. OTA on the heavily built side. Only nit pic is the way the sliding dewsheild locks, a single sharp clamp pin. Should have 3 with Delrin tips. Current single pin can mark the tube finish. Better yet could be a clamp type lock, like a tube ring one half attached to slide, other half to clamp motion. Can't wait to see the view.

Edited by drd715, 27 December 2017 - 08:33 PM.

[Bomber Bob]

Welcome to The Club!  You're gonna love the views.  No, it's not perfect, but... Good Golly Miss Molly!  It sure can rock!  A 6" APO for less than I paid for a 5" achromatic with much simpler hardware - and no case - almost 30 years ago... Tough to beat.

Edited by Bomber Bob, 27 December 2017 - 08:52 PM.

[Bomber Bob]

Enough gear talk...  What can you see with the APM 152?  Well, last night in a side-by-side with my vintage Edmund 6" F4 RFT Newtonian, my 152 wowed me with star clusters.  Probably the best views of M37 and M15 ever -- uncountable hordes of micro-points of light.  M15 really was like a disturbed bee hive -- eye-boggling!

 

Brief double star session tonight (preparation for Mars & Jupiter in the morning) in Andromeda & Perseus.  Just east of Gamma is Struve 245, and it jumped out at me 57x (RKE 21mm).  The separation is an easy 11" -- my challenge was to see the primary as light orange and the secondary as a fainter blue (both stars are about MAG 8).  The 152 displayed these as described, which makes me hopeful about seeing the subtle colors of Jove's belts.

Edited by Bomber Bob, 05 January 2018 - 10:32 PM.

[Bomber Bob]

Mars & Jupiter in the APM ED 152

 

I observed from 1015-1145 UTC, at 1000:
Temperature 23°F (-5°C)
Humidity 72%
Wind Speed Calm
Dewpoint 15°F (-9°C)
SEEING = 7 / 10 [mid-level haze]

 

First:  No CA or fringing on any object from 24x to 400x.  I had my excellent 1971 Criterion RV-6 Dynascope for direct comparisons -- both scopes have a 1200mm FL, which makes setting equivalent magnifications easy.  In the RV-6, Jupiter's zones are a pure white; in the 152, they're an off-white (a hint of gray).  Seeing varied with a mottled layer of mid-level moisture coming in from the west, and I adjusted the mag accordingly.  I used a high-quality spectros PL 5 @ 240x most often; but around 11Z, I was able to use the PL 7.5 + GSO APO 2.5x Barlow for 400x (67x / inch), and see 1 large & 2 small whitish ovals in the NEB -- like a trio of pearls.  Even at 240x I saw more fine detail than I could sketch.

 

The Galileans in this APO are 4 tiny real worlds.  Color & brightness differences were obvious at 120x.  At 400x, Ganymede had at least 3 different colors / albedo effects, while Callisto remained a faint uniform blue-gray.  Once Jupiter is better placed, I'll be able to make a serious study of these two at least.

 

Mars offered only one or two surface features, but the disk color was very similar between the two scopes.

 

Functionally, I have no complaints with the APM 152.  Focuser rotation was as smooth at 23F as at warmer temperatures.  I had thick gloves on, but had no problem snapping to a sharp focus at every magnification.  The views were overall superior to the RV-6; and, best I can recall, are sharper than those in the 6" F20 Tinsley Cassegrain.  The Meade StarFinder mount had no problems balancing, moving, and tracking at up to 400x.

 

If you're thinking about buying a Big APO, you won't regret getting the APM 152 -- it's a high-performing bargain!

Edited by Bomber Bob, 06 January 2018 - 08:08 AM.

[Bomber Bob]

Io Transit ~ 20180203 / 1015-1220 UTC

 

Ultra-thin high-level haze limited the seeing to no better than 7/10, and kept magnification at 333x or less.  No matter.  Io's disk was obvious, sharp, and faintly tinted a yellow-orange.  Jupiter's disk was much more colorful:  belts of orange, rust, shades of brown, grays, & black.  A prominent barge on the south edge of the NEB popped at just 96x.

 

I was also sky-testing a "new" 1988 Pentax J60 (60x700) that will soon be a guidescope on my ED152.  While the transit was visible in this refractor, there's nothing like watching a planet-sized moon creep above the cloud tops with tons of interesting details in the background.

 

The GSO 2" dielectric mirror diagonal was installed, but I used my 1.25" University Optics HD Orthoscopics.  At no time did I see any false color in my Big APO.

[Bomber Bob]

BIF -->  I noticed that when the dewshield is retracted, it leaves a very faint shadow on the paint -- a 1/2" band that goes halfway around the tube.  It rubs out with Windex & soft cloth -- it's not a permanent blemish.  Ditto for our red dust & dew mix, and pine tree sap.  It doesn't seem as resilient as the white powder coat I had JD apply to my old Edmund 4" refractor tube.

 

So far, no scratches, chips, or dings -- hope I can keep it that way!

[Bomber Bob]

Special Sale Price is Back!!

 

2520 for a limited time --> http://www.apm-teles...o-152-f-7.9-ota

[emilslomi]

Color on Io?! Wow! If I can't get it with my 140 I'll forever regret my choice.

 

Cheers, Emil

[daquad]

Special Sale Price is Back!!

 

2520 for a limited time --> http://www.apm-teles...o-152-f-7.9-ota

The ad says "Stock Clearance."  I wonder what that means in terms of availability of the 152?

[jay.i]

 

Special Sale Price is Back!!

 

2520 for a limited time --> http://www.apm-teles...o-152-f-7.9-ota

The ad says "Stock Clearance."  I wonder what that means in terms of availability of the 152?

 

Keep in mind APM is moving to their new facility and are trying to clear out as much stock as possible so they don't have to bring it with them. I believe they posted about it in the Vendor forum.

[daquad]

 

 

Special Sale Price is Back!!

 

2520 for a limited time --> http://www.apm-teles...o-152-f-7.9-ota

The ad says "Stock Clearance."  I wonder what that means in terms of availability of the 152?

 

Keep in mind APM is moving to their new facility and are trying to clear out as much stock as possible so they don't have to bring it with them. I believe they posted about it in the Vendor forum.

 

Thanks, good to know.

[Bomber Bob]

Color on Io?! Wow! If I can't get it with my 140 I'll forever regret my choice.

 

Cheers, Emil

Yes, but very light yellow-orangish.  On Ganymede, I see tan, brown, and charcoal.  Callisto is a uniform bluish-gray.  Europa is all pale white.

[bob midiri]

JW seems like you really are enjoying your scope!!

[Bomber Bob]

I am - no "bad" objects or views so far.

 

At 2500, I don't see how Markus is making much money off this one.  If he cut corners, I haven't found one yet.

 

If you want a Big APO, now is the time to grab one.

Edited by Bomber Bob, 07 February 2018 - 03:35 PM.

[daquad]

This winter the weather in Southern New England has been fairly horrid and when it is clear, the seeing never gets above 5/10 and is often worse.   But on clear moonless nights the atmosphere is really transparent and my NELM is six for a large portion of the sky, which prods me to use my APM 152 for deep sky, low power views.  

 

So I toyed with the idea of using a focal reducer to get wider true fields than the 2.25 degrees afforded by my 32 mm MK 80 Konig (85 degree apparent field).  The only focal reducer I could find so far is the GSO (also what appears to be  rebranded by Highpoint) that claims to give a 0.5X reduction, yielding an effective f/4 focal ratio. 

 

There are three problems with using that reducer.  Sufficient back focus is not one of them.  The first problem is that the aperture of the 2" reducer is 37.5 mm, while the field stop of my MK 80 is 47 mm, which means the vignetting will allow only a 3.6 degree true field, not spectacular, but a nice improvement over sans reducer.

 

The second problem is more, well -- problematic.  The exit pupil diameter with the 0.5X reducer is a whopping 8 mm; my fully dark adapted eye has an exit pupil diameter of 6 mm, so the effective aperture is 4.5" instead of the native 6".

 

The third problem is that the MK 80 will not perform very well at f/4, but the power is so low that it may not matter much because the spherical aberration of my fully dilated pupil may be worse than any off-axis eyepiece faults.

 

Since the reducer is only $50, I might try it anyway to see if the wide field, low power views are worth the small investment.

 

The only alternative I can see at this time for a 6" f/6 RFT is to get a 6" f/6 RFT, which would yield a 5.3 mm exit pupil and a 3 degree true field at full aperture.

 

Dom Q.

[Bomber Bob]

Dom, when I want wider fields than the APM 152, I use my 4" F5 or 5" F5 dedicated refractor RFTs; or, the 6" F4 Newt that I got here on CN for $100.  Even though the 152 is F8, I think of it like my traditional F15 achromatics...

[daquad]

Yeah, so why not use my 6" heavyweight as a 4.5" RFT.  As a buddy of mine used to say "How bad can it be?"

[drd715]

Well the 152 is here. Just opened the box and 99% perfect (only because 100% is unattainable). Will have a more in depth inspection over the weekend, may be set up the mount for test. 3.7 inch focuser amazing. OTA on the heavily built side. Only nit pic is the way the sliding dewsheild locks, a single sharp clamp pin. Should have 3 with Delrin tips. Current single pin can mark the tube finish. Better yet could be a clamp type lock, like a tube ring one half attached to slide, other half to clamp motion. Can't wait to see the view.

Here are the fixes to reach 100% perfect, I have to add these as separate pictures do to the mb limits. Even then they are over croppd

 In some instances. 

 

The first and primary fix is the dew shield slide clamp. It has been modified with a nylon 1/2 inch button that has a 1/2 inch stainless steel flat behind it. The button/puck was made from some plumbing plug that was filed down and the SS flat was a ground down SS screw head, ground thin and cut off.  The hardest part of doing this was removing the aft tube adaptor ring so the dew shield ring (unscrew the dew shield from the ring first) can be taken off the tube.  It was really scewed on there tight. Required a strap wrench in combination with strappng down the telescope tube assembly.  Duct tape the tube end ring for protection of its finish. A 1/2 inch diameter by about 4 to 5mm countersunk hole under the clamp screw is machined into this sliding ring. You will have to peel back the felt like slide material in this area to do this counter sink. Pictures to follow.

 

I did send this suggsted improvement to APM and Markus replied that he was forwarding it to the engineering department for review.

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[drd715]

Slide dew shield puck.

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[drd715]

Strap wrench

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[drd715]

Tape it first

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[drd715]

Additional improvement, add washers (SS) UNDER nylon friction washers on the ring clamps to give the plastic washers a 360 degree flat surace to glade on.

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[daquad]

drd715 you're really going to like that APM 152.  Did you notice the machined baffles inside the 3.7" focuser tube?  Both the focusers for the APM Ed's (2.5" and 3.7") are based on the Starlite Instrument models and APM has executed the design beautifully.

 

Did you get it at the sale price, hopefully?

 

I haven't had any problem with marring the tube with the dew shield clamp screw.  I removed the screw and looked inside the hole with a flashlight.  There appears to be what looks like a brass stop at the bottom of the hole, but I can't be sure.   It definitely is not felt.  I always back the screw off several turns before sliding the dew shield back; maybe that is why I haven't scratched the tube.

 

Good luck with your new scope.  Wish I had your seeing.

 

Dom Q.

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[drd715]

Extra ring and clamp bar for piggyback attachment. 

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