iStar Optical for Solar

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iStar Optical for Solar

Post by OlegLviv »

Hello everybody ! I have a few questions for you since I decided to buy a telescope lens and make my own solar telescope :seesaw

https://www.istar-optical.com/achromatic.html

1.What can you say about Istar optics?
Maybe someone buys these lenses and can tell how good they are compared to Chinese lenses nouns.

2.What comes with the lens and does the schedule they give fit it?

3.What can you say about the 150mm f10 lens?

4.What is the difference between the simple 150f10 and 150f10 Ha versions?
Does it make sense to overpay 2 times for the HA version?

Thank you :band


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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
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2xLunt 50mm
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Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
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Re: iStar Optical for Solar

Post by Bastelhannes »

I am sorry, I only can answer the second question:

The h-alpha versions seem to be optimized for the red part of the spectrum. Usually the lenses are optimized for green (our eyes work best in the green range), some manufacturers like Skywatcher shift more to the red part. That's why I prefer Skywatcher Evostars to Bresser (green optimized).

Funny, that the price is so high compared to the normal version. You just need a different spacing between the two lenses to get the optimized focus for red. I talked last week to an expert about this; I am going to stay a week at his place to learn to adjust normal telescopes to h-alpha until I am an expert.


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Re: iStar Optical for Solar

Post by GreatAttractor »

@Pablito had been using a 150 mm f/10.


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Re: iStar Optical for Solar

Post by Rusted »

I have an iStar 180mm f/12 R35 and the 150/10 H-a objectives.
Both lenses trash my [hand selected] CR150HD for image quality and allowable magnification.

I also use the 150/10 H-a for lunar imaging by leaving the Baader D-ERF in place.

A member here warned me away from the iStar H-a lenses as a waste of money.
I still went ahead and have not doubted the value of my purchase.
Others have used the larger 230mm f/9 iStar H-alpha objectives to achieve fantastic results. [J-P Brahic.]

https://www.astrobin.com/users/jp-brahic/

https://www.astrobin.com/fnda0o/?nc=all

The objectives come with collimatable cells.
Though you need a counter-cell to hold the lens onto the telescope tube.
I use straight seamed, factory extractor ducting for my tubes. Thin, galvanised steel. Not aluminium.
My counter-cells are Laminated Baltic Birch plywood turned on my lathe.
I use T-nuts to retain the clamping bolts.

P1440038 rsz 500.JPG
P1440038 rsz 500.JPG (34.88 KiB) Viewed 9647 times
P1400713 rsz 600.JPG
P1400713 rsz 600.JPG (81.59 KiB) Viewed 9647 times


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Re: iStar Optical for Solar

Post by OlegLviv »

GreatAttractor wrote: Mon May 23, 2022 5:58 pm @Pablito had been using a 150 mm f/10.
Thanks but dont see his photos shot on this telescope :D


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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
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Re: iStar Optical for Solar

Post by OlegLviv »

Rusted wrote: Mon May 23, 2022 6:58 pm I have an iStar 180mm f/12 R35 and the 150/10 H-a objectives.
Both lenses trash my [hand selected] CR150HD for image quality and allowable magnification.

I also use the 150/10 H-a for lunar imaging by leaving the Baader D-ERF in place.

A member here warned me away from the iStar H-a lenses as a waste of money.
I still went ahead and have not doubted the value of my purchase.
Others have used the larger 230mm f/9 iStar H-alpha objectives to achieve fantastic results. [J-P Brahic.]

https://www.astrobin.com/users/jp-brahic/

https://www.astrobin.com/fnda0o/?nc=all

The objectives come with collimatable cells.
Though you need a counter-cell to hold the lens onto the telescope tube.
I use straight seamed, factory extractor ducting for my tubes. Thin, galvanised steel. Not aluminium.
My counter-cells are Laminated Baltic Birch plywood turned on my lathe.
I use T-nuts to retain the clamping bolts.


P1440038 rsz 500.JPG
P1400713 rsz 600.JPG
You want to say that Celestron 150 f8 shows better than Istar 150 f10?
I have Apogee 127/f9 and want buy big aperture 150mm/f10 refractor for my Heq5-Pro and staking PST mod 2 or Lunt60.


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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
Mounh: 2xSky Watcher AZEQ6
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Re: iStar Optical for Solar

Post by Rusted »

OlegLviv wrote: Tue May 24, 2022 5:19 am
You want to say that Celestron 150 f8 shows better than Istar 150 f10?
I have Apogee 127/f9 and want buy big aperture 150mm/f10 refractor for my Heq5-Pro and staking PST mod 2 or Lunt60.
No.

Both of my iStar objectives are vastly superior to my CR150HD.


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Re: iStar Optical for Solar

Post by OlegLviv »

Rusted wrote: Tue May 24, 2022 6:35 am
OlegLviv wrote: Tue May 24, 2022 5:19 am
You want to say that Celestron 150 f8 shows better than Istar 150 f10?
I have Apogee 127/f9 and want buy big aperture 150mm/f10 refractor for my Heq5-Pro and staking PST mod 2 or Lunt60.
No.

Both of my iStar objectives are vastly superior to my CR150HD.
Sound Great!

http://fullerscopes.blogspot.dk/ its your blog?

You have Pst mod2 with Istar 150f10 without Barlow Lens or only with Baader GPC 2.6 front Pst etalon?
Without GPC 2.6 is small sweet spot?

Thanks!


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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
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Re: iStar Optical for Solar

Post by Rusted »

OlegLviv wrote: Tue May 24, 2022 7:05 am
Sounds Great!

http://fullerscopes.blogspot.dk/ its your blog?

You have Pst mod2 with Istar 150f10 without Barlow Lens or only with Baader GPC 2.6 front Pst etalon?
Without GPC 2.6 is small sweet spot?

Thanks!
Yes that is my blog. There are plenty of examples of my images on there.
My PST has a small sweet spot and it is often difficult to get an even image.

No Barlow. I change the GPC depending on the seeing conditions.
The GPC goes on the camera nose. I have 1.6x, 2x and 2.6x GPCs from T-S in Germany.


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Re: iStar Optical for Solar

Post by OlegLviv »

Rusted wrote: Tue May 24, 2022 7:44 am
OlegLviv wrote: Tue May 24, 2022 7:05 am
Sounds Great!

http://fullerscopes.blogspot.dk/ its your blog?

You have Pst mod2 with Istar 150f10 without Barlow Lens or only with Baader GPC 2.6 front Pst etalon?
Without GPC 2.6 is small sweet spot?

Thanks!
Yes that is my blog. There are plenty of examples of my images on there.
My PST has a small sweet spot and it is often difficult to get an even image.

No Barlow. I change the GPC depending on the seeing conditions.
The GPC goes on the camera nose. I have 1.6x, 2x and 2.6x GPCs from T-S in Germany.
Nice blog! I have only page on Astrobin https://www.astrobin.com/users/RamonLviv/
I have GPC 1.6x for my PST Mod 2 which I glued to the front of the etalon pst to get on f11.


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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
Mounh: 2xSky Watcher AZEQ6
Telecentric Lense: Televue Powermate 2/2.5x/4X/5X
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Re: iStar Optical for Solar

Post by Rusted »

OlegLviv wrote: Tue May 24, 2022 7:50 am
Nice blog! I have only page on Astrobin https://www.astrobin.com/users/RamonLviv/
I have GPC 1.6x for my PST Mod 2 which I glued to the front of the etalon pst to get on f11.
Thanks.

A GPC [or Barlow lens] applies different negative powers.
Depending on its position in the optical train.
Or its distance from the focal plane.

I used a Baader 1.25x GPC at the PST etalon to convert my f/8 150mm to f/10.

viewtopic.php?t=27147

When I apply a GPC to the camera nose its power is much reduced compared to the quoted power.
This is because it is very close to the focal plane. Normally a GPC sits in front of a binoviewer.
Which is a long way from the focal plane.


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Re: iStar Optical for Solar

Post by MalVeauX »

Hi,

iStar lenses are great ways to get into narrowband imaging with a big refractor via achromatic doublet lenses at various focal-lengths.

Before fussing and worrying over the quality of the lens or best figure for HA wavelength, etc, you really need to make sure you have seeing conditions that even allow you to realize any of this. Especially if you're trying to go bigger than 150mm and critically sample.

I would argue that no one will notice the difference between an Halpha optimized doublet and a normal doublet with apertures 150mm and up, because the seeing limits this completely and you'll never get to the theoretical resolution potential of these instruments in day time hardly ever, if ever, without going to very specific and unique locations that have legendary class seeing conditions that are well below sub-arc-second sustained.

Worry more about seeing than your optics.

Are they better than cheap Chinese optics? Maybe. Maybe not. In monochromatic imaging at F8 or slower? I'd argue that you'd never know the difference in solar, and only maybe in an optical bench test. You're never going to see the resolution potential or any primary attribute of these optics in most seeing conditions as you won't be diffraction limited, you'll always be seeing limited. So if it's a question of budget, you're fine with cheap Chinese 150mm F8's. If you just want something potentially better, knowing full well you probably won't be able to detect the difference, or just specifically want an F10 lens or other, then yea, go for it.

Personally I do plan on getting a 200mm i-star lens. But I won't be bothering with h-alpha version, and I also don't want it to be F10. I actually want it to be centered on green and faster focal-ratio for my purposes. And my reason is I cannot get a cheap Chinese lens this large at any better price basically. There's no competition out there for bigger fracs, so it's a seller's market.

Also, if your goal is to use harvested PST etalon for this, I would argue not to worry about base scope focal-ratio, and do not use the collimating lenses. Instead, just remove all collimating lenses and get a 3x or 4x baader telecentric and put the PST etalon after that. It will be better without jacquinot spot issues and no fussing over getting collimator lenses into a specific spot in the back focus, etc.

Very best,


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Re: iStar Optical for Solar

Post by marktownley »

Sage advice Marty.


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Re: iStar Optical for Solar

Post by Bastelhannes »

I totally agree with Marty.

I have access to nice telescopes, one of the advantages working for a telescope shop.

But... (big but).. I am doing my observations from my balcony surrounded by houses with metal roofs. After 9 am it is just guess work interpreting the images I get. Here the compromise of easy access to my balcony (lifting my pillar with AZ-EQ6, counter wieghts etc for 4 meters - big step there) and a mediocre place to observe.
I recently am decreasing my apertures from a 120 mm Evostar to a 102 mm Evostar. because the sun is more steady.

I am nerd, I want to have the perfect optics. But.. like Marty said, it's just a waste of money. And there are things outside the solar astronomy world (nice food, wine, kids, etc... you get the idea).

Just my humble opinion.


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Re: iStar Optical for Solar

Post by MalVeauX »

Heya,

I'm just trying to stress the practicality of the optics vs the seeing conditions, and the relative cost dumping into that with a variable to low quality etalon. If your goal is h-alpha, I would stress that a high quality etalon is paramount, before trying to get into high-res apertures with a poor quality or average etalon. Dealing with poor uniformity, partially off-band, etc, looks really poor in high-res.

Seeing is first and foremost.
Highest quality etalon you can get is next.
Optics last, because frankly, the seeing is your limit.

Spend accordingly!

Very best,


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Re: iStar Optical for Solar

Post by Rusted »

I find myself agreeing with Marty. Seeing conditions are the most important factor.
That said, I live in a rural location surrounded in fields.
And, I have raised the floor of my plywood domed observatory by 4m above ground level.
I was easily able to double the useful magnification visually when going from CR150HD to iStar.

The average PST etalon is not ideal for larger apertures. For optical as well as variable quality reasons.
I find no advantage in stopping down. Undetectable difference on the monitor except loss of light. [Longer exposures = lower fps.]

Perhaps Marty can be persuaded to give us the exact details of using a Telecentric with a PST etalon?
Assuming it has not already been covered but I have missed seeing it.


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Re: iStar Optical for Solar

Post by MalVeauX »

Rusted wrote: Wed May 25, 2022 12:53 pm Perhaps Marty can be persuaded to give us the exact details of using a Telecentric with a PST etalon?
Assuming it has not already been covered but I have missed seeing it.
It's well covered elsewhere, I don't want to drive this thread off topic, but the idea is if you're using collimating lenses with the etalon, you will have a jacquinot spot to deal with and it will be tiny because the field angle of a big long objective relative to the acceptance angle of the etalon is going to produce a small jacquinot spot (sweet spot). Instead, if you remove the collimating lenses and use a true telecentric barlow, and pass this through the etalon, you no longer have that issue and there's no jacquinot spot and so you should have more on-band field to work with which is ideal, and crucial on these big aperture instruments.

As for optics, in green/red, I would argue that almost all lenses that are fairly slow (F8 or longer) are going to be far better than the seeing allows. You'd never know a scope wasn't better than 0.85 strehl in daytime seeing. You're seeing limited instead, far more, than being limited by the optics. I have lots of trash achromatic doublets that are literal dumpster dives, and I can generate very sharp high res photos in mono with them, every week practically, because I have excellent seeing conditions usually.

Near UV is where the game changes in terms of trying to get the better or more appropriate optics. Refractors in general are poor in near UV. Mirrors are superior for that (but not SCT with corrector plates of course). Near UV a refractor needs to be much longer focal-ratio or have its lens re-spaced (increase air gap) to perform without SA in near UV (like calcium). So for this, yes, optics matter. And as before, totally seeing limited (more seeing limited than HA).

Very best,


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Re: iStar Optical for Solar

Post by OlegLviv »

MalVeauX I know you are a wonderful solar photographer I have been following your work for several years and also your modifications.
I am in a city near the forest and I usually shoot early in the morning from 7 am to 10 am usually sing good enough for me to shoot for 2-3 hours.
I don't think if I switch from 127 mm to 150 mm I won't be able to shoot.
I have nothing against Chinese lenses here as the lottery can get a good lens can get worse.
But I do not want to buy Chinese brands of telescopes so that it still needs to be finalized, modified, etc.I have enough ready-made telescopes.
I want to buy a good ready-made lens and from the fact that I found this option is good for me and then make the telescope itself.
Pst I sold will remain to remake Lunt 60 for a telecentric system. I have a 4x 2 Televue Powermate will it fit or do I just need a Baader?


https://www.facebook.com/oleg.lavigne/
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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
Mounh: 2xSky Watcher AZEQ6
Telecentric Lense: Televue Powermate 2/2.5x/4X/5X
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Re: iStar Optical for Solar

Post by MalVeauX »

OlegLviv wrote: Wed May 25, 2022 1:35 pm MalVeauX I know you are a wonderful solar photographer I have been following your work for several years and also your modifications.
I am in a city near the forest and I usually shoot early in the morning from 7 am to 10 am usually sing good enough for me to shoot for 2-3 hours.
I don't think if I switch from 127 mm to 150 mm I won't be able to shoot.
I have nothing against Chinese lenses here as the lottery can get a good lens can get worse.
But I do not want to buy Chinese brands of telescopes so that it still needs to be finalized, modified, etc.I have enough ready-made telescopes.
I want to buy a good ready-made lens and from the fact that I found this option is good for me and then make the telescope itself.
Pst I sold will remain to remake Lunt 60 for a telecentric system. I have a 4x 2 Televue Powermate will it fit or do I just need a Baader?
Hi,

No worries! Nothing wrong with going for better optics, my point is just that the better optics will least likely effect the results in this use, relative to other things (excellent seeing conditions, high quality high uniformity etalon, heck even a high quality focuser with step motor so you're not touching the scope is a better upgrade than worrying too much about the optical quality of a F8 or longer frac lens). By all means, get an iStar, they are excellent pretty much and worth their cost. I would even argue to over-build and do a 200mm and simply mask the objective to 150mm or less or whatever you want for seeing conditions, because you can always open it up to 200mm when seeing is exceptional which is fun.

The powermate likely won't be sufficient with an air spaced etalon for this purpose; you should probably get the Baader TZ4. That said, if you're using a Lunt 60, you don't need to go telecentric, it's a larger etalon and will have a larger sweet spot (jacquinot spot) with smaller sensors. I was just arguing for telecentric if you're using a smaller aperture etalon (Lunt 50 and PST etalons are 20mm and air spaced, so will have smaller sweet spots). Lunt 60 has a 35~38mm clear aperture etalon, so a bigger sweet spot.

Very best,


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Re: iStar Optical for Solar

Post by Rusted »

Thanks Marty!

Would the use of a Lunt 60 etalon [instead of a PST] suggest a camera with a larger sensor [than the 174] to capture the increased "useful" field?


http://fullerscopes.blogspot.dk/

H-alpha: Baader 160mm D-ERF, iStar 150/10 H-alpha objective, 2" Baader 35nm H-a, 2" Beloptik KG3,
Lunt 60MT etalon, Lunt B1200S2 BF, Assorted T-S GPCs or 2x "Shorty" Barlow, ZWO ASI174.
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Re: iStar Optical for Solar

Post by OlegLviv »

Thanks Marty but have only Televue Powermate 4x and want use her..... Im my mind that baader TZ4 or TZ3 special for Ha only marketing=)))
I haven't disassembled my Lunt 60 yet to make it telecentric and I don't know if I can disassemble it so easily how PST!
Right now my country blocked for shipping and etc and you know why!


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Re: iStar Optical for Solar

Post by MalVeauX »

Rusted wrote: Wed May 25, 2022 2:46 pm Thanks Marty!

Would the use of a Lunt 60 etalon [instead of a PST] suggest a camera with a larger sensor [than the 174] to capture the increased "useful" field?
It depends on the field angle vs acceptance angle. On my 1200mm focal length 150mmF8 frac, my field angle is sufficient with the acceptance angle of my Lunt 60's etalon that I get a full FOV in the jacquinot spot on an IMX290 sensor (small sensor, but still considered wide field in my point of view for moderate to high res HA solar). I prefer wider field because HA features are so enormous and I do not like doing mosaics.

Very best,


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Re: iStar Optical for Solar

Post by MalVeauX »

OlegLviv wrote: Thu May 26, 2022 5:29 am Thanks Marty but have only Televue Powermate 4x and want use her..... Im my mind that baader TZ4 or TZ3 special for Ha only marketing=)))
I haven't disassembled my Lunt 60 yet to make it telecentric and I don't know if I can disassemble it so easily how PST!
Right now my country blocked for shipping and etc and you know why!
Lunt mod is significantly easier than a PST mod, doesn't need custom adapters, uses commercial threads, etc. And odds of a high quality etalon from Lunt is higher than a PST etalon's quality. You don't have to make the Lunt telecentric, it's a larger etalon to begin with. Depends on your goal with it.

Very best,


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Re: iStar Optical for Solar

Post by OlegLviv »

Marty, you said that you are preparing a fresh new modification for crossing the C8hd with Lunt 60, at what stage is this modification?
And you want this Telecentric modification or PST?
If this modification will be better that 150mm dont do it my new 150mm refractor because have C8 HD, but dont have full aperture ERF :seesaw
In my opinion Refractor telescopes best of the best for sun what do you say?


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Re: iStar Optical for Solar

Post by MalVeauX »

OlegLviv wrote: Fri May 27, 2022 8:52 am Marty, you said that you are preparing a fresh new modification for crossing the C8hd with Lunt 60, at what stage is this modification?
And you want this Telecentric modification or PST?
If this modification will be better that 150mm dont do it my new 150mm refractor because have C8 HD, but dont have full aperture ERF :seesaw
In my opinion Refractor telescopes best of the best for sun what do you say?
Hi,

I have both a Lunt 60 mod and a PST mod and both work with a C8 Edge HD no problem. No telecentric, just collimator lenses. But it also works with telecentric.

I would not bother with the C8 because you cannot get a big enough DERF for this at this time. The other option is a different method of cooling (active cooling on the mirrors) if you cannot do a full aperture DERF. But this is also complex and costly and require heavy modification.

You're better off with a refractor in general. Even if you wanted a 200mm you could at least put a slightly smaller DERF internally in the light cone at say 140mm~160mm if you wanted to go big.

Very best,


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Re: iStar Optical for Solar

Post by OlegLviv »

It's great that everything works for you, but I would like to see a photo of how to do it C8 + Lunt 60 and PST


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Re: iStar Optical for Solar

Post by MalVeauX »

OlegLviv wrote: Fri May 27, 2022 12:51 pm It's great that everything works for you, but I would like to see a photo of how to do it C8 + Lunt 60 and PST
Ok, I'll do a photo of the imaging train on my next session. It's exactly the same as a refractor setup, it just inserts into the 2 inch focuser. I use a crayford on the back of the SCT instead of a visual back. So it just inserts.

Very best,


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Re: iStar Optical for Solar

Post by OlegLviv »

MalVeauX wrote: Fri May 27, 2022 1:51 pm
OlegLviv wrote: Fri May 27, 2022 12:51 pm It's great that everything works for you, but I would like to see a photo of how to do it C8 + Lunt 60 and PST
Ok, I'll do a photo of the imaging train on my next session. It's exactly the same as a refractor setup, it just inserts into the 2 inch focuser. I use a crayford on the back of the SCT instead of a visual back. So it just inserts.

Very best,
Your photos PST mod saw on ASTROBIN but with Lunt 60 dont :movie


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2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
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Re: iStar Optical for Solar

Post by MalVeauX »

OlegLviv wrote: Fri May 27, 2022 2:20 pm
MalVeauX wrote: Fri May 27, 2022 1:51 pm
OlegLviv wrote: Fri May 27, 2022 12:51 pm It's great that everything works for you, but I would like to see a photo of how to do it C8 + Lunt 60 and PST
Ok, I'll do a photo of the imaging train on my next session. It's exactly the same as a refractor setup, it just inserts into the 2 inch focuser. I use a crayford on the back of the SCT instead of a visual back. So it just inserts.

Very best,
Your photos PST mod saw on ASTROBIN but with Lunt 60 dont :movie
I haven't updated my astrobin in a while. My Flickr has all my photos from all of it. But I also post my sessions in the main forum so you can see results via my profile post search.

Very best,


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Re: iStar Optical for Solar

Post by OlegLviv »

MalVeauX wrote: Fri May 27, 2022 2:46 pm
OlegLviv wrote: Fri May 27, 2022 2:20 pm
MalVeauX wrote: Fri May 27, 2022 1:51 pm

Ok, I'll do a photo of the imaging train on my next session. It's exactly the same as a refractor setup, it just inserts into the 2 inch focuser. I use a crayford on the back of the SCT instead of a visual back. So it just inserts.

Very best,
Your photos PST mod saw on ASTROBIN but with Lunt 60 dont :movie
I haven't updated my astrobin in a while. My Flickr has all my photos from all of it. But I also post my sessions in the main forum so you can see results via my profile post search.

Very best,
Flickr see more and more photos 150mm and 120mm refractor and all 200mm+Lunt 60mm dont see)))))


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Baader D-ERF 160MM
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Lunt Cak B1200
Coronado BF15
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Re: iStar Optical for Solar

Post by OlegLviv »

Marty saw your SCT photos and want to say that REFRACTOR best of the best quality


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Re: iStar Optical for Solar

Post by MalVeauX »

OlegLviv wrote: Mon May 30, 2022 5:17 am Marty saw your SCT photos and want to say that REFRACTOR best of the best quality
The crucial difference is the atmospheric seeing. It's not easy to critically sample with a 200mm every day in solar. My seeing supports my 150mm nearly every day though, so it gets the most use. I image to my seeing limits each session.

Very best,


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Re: iStar Optical for Solar

Post by mami813 »

Hi.
I've been using an istar h@ 150mm for a long time. It's a very good lens.
Better than sw 150 f8 of the same size.
Most of the h@ results on my homepage are taken with an istar 150mm.
Keep that in mind.
www.sunview.co.kr


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Re: iStar Optical for Solar

Post by OlegLviv »

Hello everybody from UKRAINE!
I decided to buy 150 f8 Istar because my 60mm lunt has a 1.8 built-in Barlo lens and the telescope itself has f4 and not f8, so f10 will last me a long time and work worse than f8.
I am interested in the question of the truss of the open type of the telescope, what are its advantages and is it rational to make a truss for 150 mm? Thank you!


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Re: iStar Optical for Solar

Post by OlegLviv »

mami813 wrote: Fri Jun 17, 2022 2:52 am Hi.
I've been using an istar h@ 150mm for a long time. It's a very good lens.
Better than sw 150 f8 of the same size.
Most of the h@ results on my homepage are taken with an istar 150mm.
Keep that in mind.
www.sunview.co.kr
You had sw 150/f8? You say that 150 Istar f10 better Sw 150/f8?
iSTAR 150/F10 longer F8 +Lunt 60 long for me...


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2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
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Re: iStar Optical for Solar

Post by mami813 »

OlegLviv wrote: Wed Aug 31, 2022 7:59 am
mami813 wrote: Fri Jun 17, 2022 2:52 am Hi.
I've been using an istar h@ 150mm for a long time. It's a very good lens.
Better than sw 150 f8 of the same size.
Most of the h@ results on my homepage are taken with an istar 150mm.
Keep that in mind.
www.sunview.co.kr
You had sw 150/f8? You say that 150 Istar f10 better Sw 150/f8?
iSTAR 150/F10 longer F8 +Lunt 60 long for me...
iSTAR 150/F10 is much better.


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Re: iStar Optical for Solar

Post by OlegLviv »

Early in 2014 you used p.s.t stage1 mod with Istar 150 but now use Quark Gemini why because quark better?
On my mind pst mod better than quark, yes quark doesnt have sweet spot but have and indicator and low contrast......had in 2020 quark worse device as for me :band


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Telescope: TS 152/900/Bresser 102/1350
Baader D-ERF 160MM
2xBaader 1.25 GPC
2xLunt 50mm
Lunt Cak B1200
Coronado BF15
Camera: Apollo Max 432M/ Apollo Mini 429M/Player One Mars II 462M/QHY 290MM
Mounh: 2xSky Watcher AZEQ6
Telecentric Lense: Televue Powermate 2/2.5x/4X/5X
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