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Post by mikey cee on May 31, 2016 13:38:29 GMT -5
James great video. No CA but you should look into purchasing a ZWO AD corrector(ADC). I can see the orange and blue on Mars' limbs. I'm glad I bought one. Only $128 with shipping....that's highway robbery for something that good!! Mike Hi Mike Agreed on the amazing detail in the video. If Mars is high overhead in Singapore would it be likely to have differential atmospheric dispersion on the limbs? I thought this only occurs at low elevations? I'm not arguing with you, merely curious as to other possible causes under these rather special circumstances. You can see AD anywhere...even at the meridian. It is just horrendous at lower altitudes sure. But you can see the AD in James pics if you know where to look. Mike
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Post by jamesling1000 on Jun 1, 2016 6:08:56 GMT -5
Hi All...
I just want to explain a little on the 2 video clip taken by my friend's Sony RX100 digital handheld camera..
First video clip is taken directly through the eye piece of the baader zoom set at 12mm with a 2x barlow...
The 2nd video clip is taken from the TV display which i use 2x barlow with the canon 550D set at crop mode..640x480.. and this one from the TV display shows CA.. which i could not remove it even by moving the object to the centre of the screen..or changing the DSLR setting..
Normally when you visually view through the eye piece when u have the chromacorr II N.. u will see the CA once the object moves further away from the centre of the fov...
For Mars is very bright when under a clear sky and ususlly we need a polarizer to dim it down.. For last Sunday night.. due to the weather is not totally clear with light clouds.. I didn't use any polarizer at all...and I have the best view of Mars I have seen since the last 20 years..
Regards
James Ling
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Post by mikey cee on Jun 1, 2016 16:53:11 GMT -5
James I don't get it! My Chromacor N removes all CA even clear to the edge of field. However the discs of Jupiter and Mars begin to ever so slightly take on a different color hue. Move a small amount towards the center normal colors return quickly clear towards the center. Maybe it's my spacing and maybe it's the R30 prescription or a combination of both. All I know is that visually my scope performs color free. Mike
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tjn58
Junior Member
Posts: 24
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Post by tjn58 on Jun 1, 2016 22:52:14 GMT -5
Just a little off topic but I have a quick question....
Chromacor's don't come up too often for sale on Astromart and when they do the price approaches $1000.
Since there still seems to be a market for these, why are they not still manufactured? Are they made from a special glass?
Sounds like most Istar refractors with a long focal length could certainly benefit from their availability, just wondering.....
Thanks, Tom
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Post by jamesling1000 on Jun 1, 2016 23:22:46 GMT -5
Hi Tom..and All..
Yes..the chromacorr glass is special.. And I went directly to Valery to custom build his few spare units that he claims that he will only sell them to those with bigger aperture than 6"..
I have Valery to custom build for me to include the spacer (between the diagonal and the chromacorr...and the adjustable mirror diagonal..
I have tested the chromacorr II N with 3 of my refractors by even making another spacer to give me +/-5mm of adjustment but only my 8" ISTAR F8.8 at 1800mm fl works perfectly..and at just quarter turn of the thread.. CA appears even at centre of fov...so spacing distance is very important.
My C6R F8 improves drastically but is still far from my 152 APM ED APO..
My 152 APM ED APO once fitted with tbe chromacorr.. become over corrected and the image is blur..
I have to admit that the 8" F8.8 if without the chromacorr II N..fitted... the image is softer and contrast not as sharp as the APM ED APO i am having.. But once the chromacorr II N is fitted.. there is really another level above the APM ED APO simply because of the large aperture..
And as i have tested the chromacorr for almost more than a year... I think is more for visual as I took video for both my 10" mewlon and the ISTAR.. The mewlon shows nice video quality than the Istar...
Regards
James Ling
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Post by jamesling1000 on Jun 3, 2016 23:03:40 GMT -5
Hi ALL... As I am back from my oversea work assignment, I am able to give a brief summary on last weekend Mars observation and public outreach activities from our small group...... Last weekend after almost 2 weeks of poor weather, mainly cloudy and raining , only Friday and Sunday , the weather is suitable for doing some serious observation of Mars.... last Friday night , our group starts around 9.30pm... but when I am back home from oversea , is almost 10pm... so I only took out my 10" Mewlon , which is very portable and only use only light weight tripod and lighter counterweights... I wanted to present on last Friday night event coz I wanted to show how frustration one can be when you encounter problems in the field....especially I even invited my boss and his whole family to attend... My losmandy RA motor gear hsg crashed into the DEC setting circle, when I slew the mount to Mars which is very high around 11.30pm almost at zenith... The mount no longer can track as the RA gear came off from the worm, and Mars need high power to view so is frustrated to keep hand adjust the scope to centre the view.... And the situation worsen as my finder led light source battery is flat......when I want to use it to centre the object in the finder? But with a bit of innovation idea, I took out my roll of scotch tape and secure the RA gear assy housing to the worm , I managed to get the mount track again..... And I am able to show the public the view of Mars at high power at more than 300x , including my boss and his family arriving around 12am... On Friday late night session I have shown the public Mars, Saturn and Moon through my 10" mewlon, but when I power up my TV display, the screen blank off after working for a few minutes....and I no longer able to use my DSLR to show the public the planets on the TV display which I used to do so... Regards James Ling to be continued.....
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Post by jamesling1000 on Jun 4, 2016 0:05:38 GMT -5
Hi ALL... The late Friday night session ends around 2am....and when I reach home, I checked the cabling connection and found that is only a blown fuse.....which is 1 amp rating? ? and I plug in another one with a 5amp rating and the TV display works, and is not spoil.... So I don't have worry for the next session, which still have Saturday or Sunday to try our luck again... As usual... Saturday weather is again a complete washed out.....so really hope Sunday the weather is good and do not want to miss the opportunity to have Mars the closest in last weekend, or else will be the following weekend but half our group is heading North to the dark sky again.... At last Sunday afternoon is sunny although is a bit cloudy... So our group is willing to do a short 3 hours session from 8.30pm till 10.30pm... We could not stay up back this time, coz the next day we need to get back to work, and myself need to wake up at 5.30am and set off to work... Although this time is a short session, but I still load up my 8" Istar and the mounting accessories including my Tv and table set into my car, and travel all the way to the park. You can see from the photo so much astronomy gears being unloaded from my car at the unloading point at the park, then i must park the car in a nearby multi-story car park more than half a km away and walk back to the park... Regards James Ling TO BE CONTINUED.....
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Post by jamesling1000 on Jun 4, 2016 0:43:09 GMT -5
Hi All.. Setting up this 8" Istar for outreach session has been a normal routine since I cut the tube to two half and join them together with a sleeve holder...so that it can easily be transportable in a car.. I can set up the OTA and the losmandy mount by myself except when mounting the OTA onto the mount dovetail...but usually at every session, we have more than 5 person around, so it isn't difficult to bring out the big achro for outreach session.. The following are the photos for last Sunday setup... Even while I am setting up, the public are anxiously waiting to look at Mars Regards James Ling TO BE CONTINUED...
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Post by jamesling1000 on Jun 4, 2016 1:21:25 GMT -5
Hi ALL.... These are some of the photos that you can see the public automatically come to you, instead of the need to invite people over to our scope at every setup... Many people even taking this opportunity to snap photos of the family members, friends, etc....together with the scope.... For last weekend Sunday setup.... at around 9pm, Mars is not very high , but this big 8" istar is able to show high contrast view of Mars with Syrtis Major so dark and resemble like the map of India....when i told the public to look for...with my baader zoom set at 8mm giving 225X. Is very strange, Friday night the weather is clear of clouds at the regions around Mars, and is so bright that I need to add the polarizer in order to be able to see Mars, but Syrtis Major on Mars seen through my 10" Mewlon is very faint.... The only difference on Sunday night when seen through the 8" istar is that the weather seems to be having some light clouds covering Mars, and I don't need any polarizer to add on.... After half an hour of observing... I add a barlow and power it up to around 300X, and Mars's surface contrast is so clear and detail, which i can't describe it except asking my friends to come over and see it for themselves... I never seen Mars in such high contrast detail before through my other 2 bigger scopes, c14 and 10" mewlon... Is either the seeing for that night is great or the chromacorr II N works beautifully on this scope... Regards James Ling
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Post by jamesling1000 on Jun 4, 2016 1:43:59 GMT -5
Hi ALL.... As I always include during every outreach session, towards the end of the session, I will setup my TV display output from my canon 550D DSLR through my telescope...for the public to watch and even take some photos from the TV display... So for last Sunday night session, I do the usual setup and following are some photos... Getting the image of Mars onto the TV display... This is a photo I took from the TV display showing Mars and its Syrtis major , which is output from my canon 550D DSLR set at crop mode with 2x barlow (IN CROP MODE YOU GET A BIGGER BUT SOFTER IMAGE, OTHERWISE YOU NEED at least 5x barlow which the image is still not big ) Regards James Ling
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Post by jamesling1000 on Jun 4, 2016 1:59:50 GMT -5
Hi ALL...
Last weekend , I really enjoyed the 3hrs short session , with my 8" ISTAR only pointing at Mars, instead of Saturn and Jupiter, especially when I can seen so much fine details on surface of Mars....although it is still quite small, even I managed to power the scope to 450x towards end of the session....
I cannot believe what I have seen from my own eye, through the eye-piece , and perhaps maybe due to my location is at 1 deg N equatorial region, which Mars can rise and move to overhead ...( OF COURSE THE CHROMACORR II N PLAYS AN IMPORTANT ROLE ) Also my 8" Istar passive cooling vents make it no cooling required and once is setup, not much time is needed to cool down , in our region....
Lastly hope all of you enjoy this report for my last weekend outreach session.....
Regards
James Ling
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Post by jamesling1000 on Jun 5, 2016 14:07:55 GMT -5
Hi ALL..
Following are 2 video clips taken by my canon 550D using crop mode.. Just want to know from all of you.. your opinion which one is better...
Mars On 29th may 2016 Through 8" ISTAR Telscope:
Mars On 5th June 2016 Through tak 10" Mewlon:
regards
James Ling
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tjn58
Junior Member
Posts: 24
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Post by tjn58 on Jun 5, 2016 22:19:58 GMT -5
Hi James,
Great series of photos - looks like you worked really hard and provided a lot of people some great views. As far as the two videos.......even though this is an Istar forum, I would have to say the Mewlon showed the sharper images.
Thanks for sharing, Tom
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Post by jamesling1000 on Jun 5, 2016 23:58:41 GMT -5
Hi Tom..
Thanks for the feedback... Yes.. I have the same opinion the mewlon video shows better .
But strange... Mewlon at 3000mm fl..the Mars video image size is very small whereas for ISTAR is very huge.. although I used 2x barlow for the Istar at 1800mm fl.. unless the DSLR which is mounted onto the diagonal is like a barlow while for mewlon the DSLR is mounted directly to the visual back...
Also the seeing condition is very important..previous friday weekend mewlon couldn't show a high contrast image through the eyepiece but last night..is completely different.. My memory of Mars visual image during previous Sunday is much better then last night visual view of Mars through mewlon...as I used 2 polarizers to get the clear contrast visual view...
Regards
James Ling
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Post by jamesling1000 on Jul 15, 2016 21:14:47 GMT -5
Hi ALL.....
Just want to share this video clip which was taken last week during one of my outreach activities at the local library area, which for the past one over year, I did most of the outreach in the park, because this library open area has been under extensive renovation.....
This is a time lapse video clip taken by just the hand phone which anyone of us can do so ( u can download the free software if it does not come with the hand phone ), and just by setting it to 1 sec mode , you can have the whole 2 to 3 hours of whole activities compressed to just a couple of mins...
Although in this time lapse video clip, is not showing the setting up of my 8" ISTAR, but I think from the video clip, you can tell from the public responses and reactions, why people like many of us, want to do public outreach, simply we know what type of enjoyment we can bring out to people , who are willing to stop by for just a bit of their spare time to view through our telescopes ( FREE OF CHARGE ) , and physically look at the objects in the sky such as the moon and planets, which otherwise almost all thought that only from books, magazines and the TV media, are what they know of..
And this short time lapse video clip is also being posted in Cloudynights under POST A PICTURE OF YOUR REFRACTOR...
I hope those in ISTAR SCOPE CLUB who can access to utube can enjoy this time lapse video clip, and if you have any commend pls feel free to bring forward for my improvement in future outreach....
Regards
James Ling
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