My Istar 127mm f/8 Refractor build .

[Brian Nordstrom]

Hi all , I have now recieved my new Istar 127mm f/8 Achro lense in cell it arrived the other day , 10 days from Istar in the USA to me here in Darwin Australia , awsome service Istar ! .

I have posted a little on ' Steves 127mm Istar build ' thread here on members equipment reviews , so if you want you can start there for a little background on my build .

I picked up a brand new old stock " Saxon " ota for $150 minus its lense , the previous owner did not know what happened to the origonal , it was how he got it .

This got me thinking , how about building a scope around this OTA using an Istar 127mm f/8 achromat ?

Do away I went , and a few e/mails to Mike Hardin at Istar latter I had the lense on its way , extreamly good customer service , I cant stress that enough , very ,very good .( A few larger scope manufactures that I wont mention could learn a thing or two from Istar on customer service, you know who I am talking about ? )

While I waited I cut the tube to its right length ( - 150mm from standard ) , I already had some Rings , finders a Diagonal and TelVue Gibraltar mount sitting around doing nothing so over a couple of weeks I got it all together ( see photo's ).

Anyway 10 days after Istar recieved my PayPal payement ( $453 aud) the lense was waiting for me after work the other day ,,, Yippe!! .

I need to machine up a " Counter cell " to mount the beautifully made adjustable Istar cell to my tube , but the Saxon ( Vixen ? ) cell is the same size as the Istar's so I just popped it out and fitted it into the Saxon cell ( non adjustable , but very well made as well) .

I will hopefully get the counter cell done by Christmas .

On the Saxon OTA , the 1 1/4 inch R&P focuser is as good as the focusers on my Takahashi's ( Vixen again? ) but anyway its staying on .

Now the good stuff , How does it perform ?

Well last night was first light on the moon at 10 days old and WOAW!!! what a great lense ! so sharp with awsome detail seen , yes there was a very ! slight yellow tinge to the edge of the lunar limb but the terminator ( where the best action is seen anyway ) was totally pitch black with great contrast and ZERO !! CA seen even at 110x in my 8mm TV Radian , impressive .

The moon in my 24mm TV Panoptic at 42x was as good as any I have seen , and this with the lense in an un-ajustable Vixen cell Very Very good , thanks Istar , I am more than happy .

These lenses are so good .

Here is a few photos , notice the photo of the paln frond , that was taken at 110x in my 8mm Radian about 200 meters away , see the lack of CA on the fronds edge's ? it is non existant , awsome for a 127mm achro working at f/8 ( 1000mm fl )

I am rapped with this scope , and I hope you all enjoy .

There will be updates .

Brian .

[southernman]

Gotta love a big frac!! Well done.

[Brian Nordstrom]

Yea I do , here is a photo of the lense cell , it seems a little different to Steve's , Istar must have changed the desigh a little ?

Brian.

[Brian Nordstrom]

I forgot to say Southernman , I have a Saxon 150mm f/8 fitted with a Chromocor back in NZ ( here it is and its awsome ) , my nephew in Hamilton is using it while I am working here in OZ ,, yep nottin like a good frac .

Brian.

[John]

I forgot to say Southernman , I have a Saxon 150mm f/8 fitted with a Chromocor back in NZ ( here it is and its awsome ) , my nephew in Hamilton is using it while I am working here in OZ ,, yep nottin like a good frac .

Brian.

I used to have one just like that - mine had the Chromacor II in it. It was the 3rd Chromacor equipped refractor that I've owned. They produce good results

Your 127mm Istar build looks very nice. I recently investigated getting an Istar 127mm F/12 with their tube and the R30 objective in it. The costs were reasonable but the weight of the tube was rather shocking !

Using an Istar objective in your own supplied tube makes a lot of sense I reckon.

[A McEwan]

Wow! That is one seriously handsome scope! You must be very proud of it - I know I would be.

The piuc of the palm frond is exceptional. I must say, I can just about detect the faintest trace of CA on it, but it is so minimal as to be irrelevent, and a lot better than my 150mm f8 even with Semi-Apo filter would be on such a tough target. 127mm at f8? Superb.

Istar are definately a name to watch, and with customer service matching the quality of the goods they're putting out, they could well end up with a reputation as good as TeleVue, in the long run.

Hurrah for the little guys!

Ant

[michael.h.f.wilkinson]

Nice looking piece of kit. Glad the view through the scope is as nice as the view looking at the scope

[nightfisher]

After seeing this build, i looked on the Istar website, and found a 104mm f12 lens set, it had me thinking of swapping out the chipped lens from my antares and shortening it to 1200mm but this would defeat the point of getting the f15

[Brian Nordstrom]

• Thanks all for you kind words , here is a couple of photos taken last night 25th november , from here in Darwin .
  

It was an average night with lots of seeing passing in front of the view , high atmosphere.

The 1st is taken with my 22mm TV Panoptic at 45x .

The 2nd is taken with my 8mm TV Radian at 110x .

Hope you enjoy .

Oh yes these are taken with my HTC smart phone held over the eyepieces .

Again notice the lack of CA , I am impressed to say the least .

Brian.

[John]

Hi Brian - thanks for posting the photos.

It might be my eyes but I can see a fair amount of CA in the images - has the camera phone accentuated it do you think ?.

[Brian Nordstrom]

Probably both , there is a little to my eyes , but as you know a photo will bring out more thats invisible otherwise .

The moon is a tough target on any scope especially 127mm worth of light at f/8 , but the true to life images in my eyes is very good .

I designed uo the counter cell for the Istar adjustable cell tonight and will look at machining it up soon , I think that will help the image a lot .

Looking good ,,

Brian.

[John]

......The moon is a tough target on any scope especially 127mm worth of light at f/8 ......

Quite true. An 5" crown / flint achromat is going to need to be somewhere between F/15 and F/17 to appear colour free on the lunar limb, bright planets and stars.

When I was discussing the potential purchase of an Istar 127mm F/12 based on the Istar R30 anastigmat objective I was told that even that would show a little visible CA on the brightest objects. The R30 is designed to show 30-60% less CA than their conventional achromats.

[Brian Nordstrom]

I dont know what happened to my last reply ? hope this is not a repeat.

Yes those R30 Istar Achro's look like the go , I will look at building a scope around one maybe next year ?

Any way here goes again ...

Last night I was out testing my new 2nd hand 9mm T1 Nagler in the Istar on some terrestial objects ( very nice ) and a native pigeon perched in a tree about 100 metres away .

These are a large bird about chicken sized and snow white , just beautiful they are .

Being so white and it being around 3pm in full sun the photo ( taken with my HTC phone again ) shows how well the CA is supressed in this Istar achromat lense , nice .

On the counter cell I did a scavenge around work today fot a piece of alliminium big enough and might have found the perfect off cut ?

More to follow .

Brian.

[Marki]

Thats a good looking scope Brian!

I've looked at the r30 istar achros as well. Was very tempted, but having seen one in the flesh, so to speak, its a little too big for me to manage with my current domestic arrangements (need a bigger mount and bigger garden!).

[Brian Nordstrom]

Hi all , I done a little more on the Istar scope yesterday , I made up a small rail 25mm wide and 200mm long , bolted to the top of the tube rings to hold them together as one unit , painted it hammerite black and fitted it , looks good I think .

And I also painted the inside of the dew shield flat black as the origonal Saxon black? ( dark grey ) paint was nowhere dark enough , it is now tho.

I will start the counter cell next week and when I finish it and strip the scope again to fit it I will paint the inside of the tube with the same paint as the dew shield has been done .

More to follow .

Brian.

[Brian Nordstrom]

Hi all , well I have compleated machining up the counter cell and have just now finished final assembly , so the scope in now finished ???? sort of .

I have taken some photos of the steps I took this morning and here is a few for all to see.

Looks really nice I think , and on that I cant praise the TelVue Gibralter mount enough , its very light , very sturdy and its movements are so smooth with zero jerkyness , just perfect for this scope .

All I have to do now is wait for a clear night and do final columination of the lense and thats it . Yippe ! .

Hope you all enjoy .

Brian.

[A McEwan]

Very nice! Bet it'll be outstanding in that cell, with the collimation finalised! Enjoy!

Ant

[Marki]

Looks very nice indeed. I look forward to your first light/collimation test report. Do you plan to change the logo on the tube at all?

[nightfisher]

Brian, superb job, really superb, i wish you well for first light

[Brian Nordstrom]

Thanks for your praise guys .

Ant , we are have the wet season just starting here in Darwin , so clear nights will be at a premium until about March .. Ouch ! but that the price we pay here for 7-8 months of ground hog perfect nights ( The DRY !! yea ) ,, sorry but true months of perfect nights during the Dry season .

Marki , no . I will keep the Saxon Logo on this scope . I have asked Isatr Optical for some stickers and hopefully they will send some , like TelVue do . and Oh yea I recieved an e/mail from one of the Saxon people today and they are rapped! , I was told that they may start using Istar Optical lenses in their scopes , cool .

More to follow .

Jules , thanks mate but as I said earlier the wet is upon us here in the NT of Australia , but hey , we , like you guys get the odd awsome night even during the wet season ( Monsoons ) .

More to follow .

Happy , happy ,,,

Brian.

[John]

This project is looking great Brian

......... and Oh yea I recieved an e/mail from one of the Saxon people today and they are rapped! , I was told that they may start using Istar Optical lenses in their scopes , cool .

More to follow .

The above is interesting. I seem to recall Saxon as being one of the brands that Synta use for scopes that are also marketed under the Skywatcher brand.

I wonder if Synta / Saxon / Skywatcher would consider putting third party optics in some of their scopes ?.

Which is what you have done very nicely of course !

[Brian Nordstrom]

I made an adaptor to put the Istar/Saxon on my Ioptron IEQ45 that normally holds my Tak Mewlon 210 , looked handsom so I snapped a few photos , what do you think ?

Brian.

[Brian Nordstrom]

This project is looking great Brian

The above is interesting. I seem to recall Saxon as being one of the brands that Synta use for scopes that are also marketed under the Skywatcher brand.

I wonder if Synta / Saxon / Skywatcher would consider putting third party optics in some of their scopes ?.

Which is what you have done very nicely of course !

I hear you John , Saxon have used ' Antares ' out of Canada ,' Vixen ' out of Japan and ' Hoya ' out of China over the years so I am sure there is a way to get this ball rolling , Istar offer full builds so its up to them to sort the fine print so we amateur astronomers get the best quality scope we can afford .

The world is becomming a global community weather we like it or not , so i recon if this happens , all and good .

There a quite a few people down here looking at this marrage , hoping it happens .

Brian.

[Marki]

That's looking really fine, Brian! Hope you get a suitable night at some point in the near future then .

By the way, how do you find the iEQ45? I have a minitower II and its really great for my Equinox 80mm - easy to align and set-up and seemingly very accurate. I can leave it a on target for hours and still see the subject bang in the middle of a 5mm ortho field (did this for three hours with Jupiter last night). Not so good for my other fracs though so been considering something a wee bit bigger, and (funds permitting) the 45 seems like a nice option.

[Brian Nordstrom]

That's looking really fine, Brian! Hope you get a suitable night at some point in the near future then .

By the way, how do you find the iEQ45? I have a minitower II and its really great for my Equinox 80mm - easy to align and set-up and seemingly very accurate. I can leave it a on target for hours and still see the subject bang in the middle of a 5mm ortho field (did this for three hours with Jupiter last night). Not so good for my other fracs though so been considering something a wee bit bigger, and (funds permitting) the 45 seems like a nice option.

Hi Mark , I have had my IEQ45 for over a year now and like you , just love the ease of set up .

I plonk the mount / tripod down , point roughly south and turn it on and by the time I have the OTA ready to fit to the mount it has made GPS lock . I fit and balence the tube and send it to anything ( except the sun ) .

Then I sync to that target and thats it , 3 minuites and its away all night .

I have only ever done a 2 star alignment and find the ' Sync to target ' is as accurate , cool mounts , easy to use , solid and sexy .

I dont need anything else .

Oh yes its never missed a beat .

Brian.