New APM 152 F8 ED APO

[James Ling]

Hi Chia....

If I am not wrong, this OTA with tube rings and dovetail is 10kg....

I purchased the whole pkg , which includes the finder, focuser and the case, is usd3990, inclusive of delivery.


REgards

James Ling

[James Ling]

Hi All....

This is a picture I took on the Sun showing the details of sunspots, from the new 152 APM ED APO using the Lunt solar wedge with a continuum filter, with 2X barlow , using the canon DSLR....

If weather is good tonight, both Richard and myself will be doing the scope shootout between the APM ED APO and APM triplet APO....around 11pm...
Otherwise it will be tomorrow night at 9pm....

Regards

James Ling

[Gary]

Beautiful! Did you guys manage to observe and compare scopes last night?

[James Ling]

Beautiful! Did you guys manage to observe and compare scopes last night?

Hi Gary and All....

Yes.... Tonight both Richard and myself have finally decided to do the shootout between his APM triplet and ,my new APM ED APO....

We started quite late after 11pm, and the following are how we do the shootout...



Photo shows Richard doing his APM triplet APO setup...



Photo shows the new APM ED APO setup ready for the shootout



Photo shows the shootout is done by using the same eye piece , first over the APM triplet APO, and we viewed at Jupiter and its moons ....



Photo shows the same ep is brought over to the new APM ED APO , and we viewed at Jupiter and its moons....


Hi ALL......

For this shootout, we only use Jupiter, to compare the contrast , and the result is the APM Triplet APO stands out as the disc is very clean , while the ED APO is softer....
Both shows nice contrast of clouds bands even power up to over 300X...
I also noticed the moons of jupiter through the triplet is a very clean disc.
The ep used is the Lecia zoom with a barlow for this shootout comparison....
ON Jupiter, we do not notice any CA, as the thin stripes of red on one side and blue to other side , is also visible on both scopes.... which Richard commented is not CA...
But towards the end of the shootout, I slew the scope to the 20 day old moon, and we notice the CA, which is a very thin stripe greenish / yellow colour , that for both my C6R F8 and Istar is thicker..., but quite close to my WO88ED CA level on the moon...

Perhaps Richard will be able to make a comment on this new APM ED APO, better than my opinion...

Regards

James Ling

[Gary]

James & Richard, thanks for taking time off your busy schedules to do the scope comparison and report. Singapore astronomy is blessed with the presence of these 2 great scopes whose owners are willing to share their views with the public via sidewalk astronomy sessions.

[James Ling]

Hi All....

Tonight between 8pm till 10pm, there may be another round of shoot out for the APM ED APO and Triplet APO....

And this is provided weather is good tonight.....

The venue is at my place , at the following address:-

Jurong West St 42, Blk 407.....

Anyone who is interested , can call me for confirmation....at my contact no: 97658072....

REgards

James Ling

[rlow]

Here is my first impression of the APM 6" f/8 Chinese ED Doublet compared with APM 6" f/8 LZOS triplet conducted last night 1 Jan 2013 in Jurong West, Singapore. I would like to extend a note of thanks to our observing buddy James Ling for this opportunity.

It was a quick and casual observation and I will only comment on the optical performance here. We spend about half hour observing time from 11:45pm onwards to observe and compare Jupiter which had culminated at almost zenith, spending a few minutes at a time on one scope and switching over to compare the image in the other scope and vice versa.

We compared using Leica ASPH zoom with Zeiss/Baader Abbe Barlow with 40mm T2 extension tube on both scopes side-by-side, giving a max. magnification of 363x.

Seeing was quite good at 8/10, with occasional moments of calm when the image was sharp and still. We do not have scope cool-down issues here at the tropics.

The APM 6" f/8 Chinese ED Doublet performed well optically though at first glance, both of us had already independently observed that there are immediate subtle differences between both scopes.

The image in the APM 6" f/8 LZOS triplet was noticeably slightly sharper at the same magnification, and showing slightly more planetary detail than the APM 6" f/8 Chinese ED Doublet. The image in the APM 6" f/8 Chinese ED Doublet was slightly softer in comparison. The APM 6" f/8 LZOS triplet was able to hold sharp image at slightly higher magnification than the APM 6" f/8 Chinese ED Doublet.

The image in the APM 6" f/8 LZOS triplet was colourless and neutral in tone, with a tiny tinge of red & blue seen at opposing limbs due to atmospheric dispersion. The image in APM 6" f/8 Chinese ED Doublet was warmer in tone, and Jupiter seemed to present to me a somewhat not-so-clean image. There was no visible purple fringe like the C6R, however both of us noticed a tiny tinge of red glow is visible around the Galilean moons at >300x. There is also a thin green-colour fringe around the bright Lunar edge at 66x magnification.

The image in the APM 6" f/8 LZOS triplet was noticeably brighter compared to APM 6" f/8 Chinese ED Doublet at the same magnification. I was somewhat surprised as I had previously noticed a slightly brighter image in a doublet compared to a triplet. Maybe the difference could be attributed to the difference in star diagonals: the APM 6" f/8 LZOS triplet was using the AP Maxbright diagonal while the APM 6" f/8 Chinese ED Doublet was using the APM 99% dielectric diagonal. In hindsight, we should have conducted the test comparison using the same star diagonal so as to eliminate this variable in our comparison.

These are only first impressions based on a quick casual test. These differences seen are subtle and evident only when we do this A-B test comparison side-by-side. Kindly note that our observation of the optical performance of the APM 6" f/8 Chinese ED Doublet is based on just this one sample #002 and perhaps may or may not be representative of the final production scope.

I am quite impressed with the overall optical performance of the APM 6" f/8 Chinese ED Doublet. I am quite sure that there will be many people, especially those who are value-conscious, who would be satisfied with the optical performance APM 6" f/8 Chinese ED Doublet. For those who are more quality-driven or purist in nature, the APM 6" f/8 LZOS triplet etc would probably be their choice. I am in the latter group and I am happy to stick with my home-built version of the APM 6" f/8 LZOS triplet.

[rlow]

James using the APM 6" f/8 Chinese ED Doublet. Kindly note that the dew shield is not extended in this photo.

[stargazer]

Hi Richard & James,

Thanks for sharing your observations! And the yellow giant refractor...is that the yellow submarine which we were so proud of? Thought it has been sold liao?

Do missed the fun times we had when organised side-walks especially during festivals.

[rlow]

Yes it is the yellow sub. No one wants to buy it, so it is still in cold storage til this shootout.