Back focus for Lunt 60mm TT BF1200

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dpastern
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Back focus for Lunt 60mm TT BF1200

Post by dpastern »

As the title suggests, I am unsure of what the back focus is for imaging with the Lunt 60mm TT scope. I have a ZWO 1600mm pro which I want to use for full solar disc imaging. I couldn't find this information on the Lunt website, and didn't find it in the Lunt instruction guide either. I had a quick search via Google but couldn't find an answer. I also searched on these forums and found nothing.

Help appreciated as I'm a total newbie to both imaging and solar imaging/solar scopes.

Cheers,

Dave


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Re: Back focus for Lunt 60mm TT BF1200

Post by marktownley »

Not sure of the back focus but I don't think you will have any issues. Just give it a try?


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Re: Back focus for Lunt 60mm TT BF1200

Post by robert »

The Lunts usually have a long draw tube and so a big range of focus position.
Robert


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Re: Back focus for Lunt 60mm TT BF1200

Post by dpastern »

Thanks guys. Will play with the BF1200 positioning in the focuser and of course, adjust via focusing and then dialling in the tilt tuning and see what happens.


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Re: Back focus for Lunt 60mm TT BF1200

Post by _Zakalwe »

I've used an ASI1600 on my Lunt L60.
The slow acquisition speed will be your biggest challenge. An ASI178 makes a far better match and it will give a full disc with your setup.

<edit> the 1600 also gave the worst Newton's Rings that I have ever seen too. However, your mileage may vary as NRs tend to be a bit random.

This was the result after processing


ImageASI1600 Lunt DS 60 Inverted Mono by Stephen Jennette, on Flickr


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Re: Back focus for Lunt 60mm TT BF1200

Post by dpastern »

Sorry for the lack of response to your post - I completely forgot about the thread and didn't get any email notifications of your reply.

I figured out how to get the focus etc, by adjusting the distance to camera's sensor with the 1.25" nosepiece etc. With that said, I had not been able to focus the surface detail with the 1600, or with an eyepiece. Until yesterday. I managed to get the Sun's surface perfectly in focus with my 20mm Vixen eyepiece and oh what a treat!

Your image is gorgeous and if I can get something like that, I'd be really happy!

I have a 290mm mono camera (has not been used yet) but it won't do full solar disc imaging with the Lunt. The 178 looks like a great option, but I unexpectedly lost my job in March and have not been able to gain employment since. Perhaps when I get new employment!

Many thanks again. I have other questions, but will post a new thread with them.


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Re: Back focus for Lunt 60mm TT BF1200

Post by EGRAY_OBSERVATORY »

As Zakalwe/Stephen has confirmed and with my own two Lunt 60mm scopes (Ha and Cak) the ZWO ASI-178MM cameras work very well for full disk imaging and are fast too. No Newton Rings experienced with the basic set-up at least. Barlow lenses might introduce NR's but not definite...

Robert's answer is also very correct.

Terry


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Re: Back focus for Lunt 60mm TT BF1200

Post by dpastern »

EGRAY_OBSERVATORY wrote: Sun Aug 29, 2021 4:41 pm As Zakalwe/Stephen has confirmed and with my own two Lunt 60mm scopes (Ha and Cak) the ZWO ASI-178MM cameras work very well for full disk imaging and are fast too. No Newton Rings experienced with the basic set-up at least. Barlow lenses might introduce NR's but not definite...

Robert's answer is also very correct.

Terry
The 178 looks like a promising option, need $$$$ before I can consider it! Also considering a 224MC for "basic" planetary imaging. I'm gonna end up owning 4 ZWO cameras lol!


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Re: Back focus for Lunt 60mm TT BF1200

Post by marktownley »

Just be aware that the ZWO 178s suffer 'randomly' a fixed pattern noise issue (grid square pattern like graph paper) in Ha, if you buy one of these buy it from somewhere you can return in the event of a poor sample.


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Re: Back focus for Lunt 60mm TT BF1200

Post by dpastern »

marktownley wrote: Mon Aug 30, 2021 8:47 am Just be aware that the ZWO 178s suffer 'randomly' a fixed pattern noise issue (grid square pattern like graph paper) in Ha, if you buy one of these buy it from somewhere you can return in the event of a poor sample.
That is really good to know, thank you! The sad thing is that local retailers price gouge Australian consumers VERY VERY VERY VERY badly. Example:

Bintel - AUD $579, out of stock. https://www.bintel.com.au/product/zwo-a ... 2b26af01d5

Agena Astro - USD $299 (AUD $409), in stock. https://agenaastro.com/zwo-asi178mm-cmo ... amera.html

I'd be paying at least AUD $15 for shipping in Australia from Bintel. Probably USD $30 for shipping via Agena. I'd still be saving AUD $120 allowing for shipping costs. I lose a bit of that cos we're now forced to pay GST (tax) on purchases privately imported into Australia (the Australian government introduced this a few years ago to appease Australian retailers and distributors whilst screwing over consumers, who make up 99.99999999999999999% of the voters - go figure!). I'm not sure how the Australian government is supporting its constituents...anyway, diatribe over.

This price gouging occurs for everything in Australia, we get priced gouged on everything. The above example is kind of close in terms of prices after shipping costs and import taxes. Other stuff is much more different. As an example, to back up my thesis, I was interested in purchasing a DAP (digital audio player) early 2020. I had considered a Fiio m11, which at the time, retailed for around, on average, USD $450 (retail of course). At the time, that was around AUD $620. Local asking price for this very product, from both of the Australian retailers? AUD $1299. I kid you not. Just remember, the US price is a retail price, wholesale price is probably $200 USD. Which makes the price gouging on Australians even WORSE!!!!

I buy as little as possible in Australia, I refuse to support local distributors and retailers who price gouge. They can go the way of the Dinosaurs as far as I'm concerned!


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Re: Back focus for Lunt 60mm TT BF1200

Post by EGRAY_OBSERVATORY »

That's interesting, as converting the web-link prices you have submitted, converting them to U.K. £-sterling suggests the 178MM is cheaper in Australia than here in the U.K.

Obviously being careful to do the conversions from Australian-dollars to whichever currency, that may not be correct.
Two reliable firms here at least, such as https://www.firstlightoptics.com/ and https://www.modernastronomy.com/ can be checked for our current prices to convert and compare with those in Australia. Obviously what post and import-duties etc., might be added, is something you can work-out.

The price you pay for any astro-imaging camera, could well dictate the quality and as Mark T., says, checking with any supplier that a returned-item due to a snag is available for an exchange or refund..

You could easily Email one of our suppliers (of which there are at least six or more in the U.K.) to check on their availability and prices with any extra costs ?

Remember to use :- https://astronomy.tools/calculators/field_of_view/ for Field of View through your SolarScope etc.
and
https://astronomy.tools/calculators/ccd_suitability for camera/pixel size recommendation.
plus
https://astroforumspace.com/best-zwo-ca ... otography/ for camera advice

Wishing you the best.
Terry


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Re: Back focus for Lunt 60mm TT BF1200

Post by dpastern »

EGRAY_OBSERVATORY wrote: Mon Aug 30, 2021 11:24 am That's interesting, as converting the web-link prices you have submitted, converting them to U.K. £-sterling suggests the 178MM is cheaper in Australia than here in the U.K.

Obviously being careful to do the conversions from Australian-dollars to whichever currency, that may not be correct.
Two reliable firms here at least, such as https://www.firstlightoptics.com/ and https://www.modernastronomy.com/ can be checked for our current prices to convert and compare with those in Australia. Obviously what post and import-duties etc., might be added, is something you can work-out.

The price you pay for any astro-imaging camera, could well dictate the quality and as Mark T., says, checking with any supplier that a returned-item due to a snag is available for an exchange or refund..

You could easily Email one of our suppliers (of which there are at least six or more in the U.K.) to check on their availability and prices with any extra costs ?

Remember to use :- https://astronomy.tools/calculators/field_of_view/ for Field of View through your SolarScope etc.
and
https://astronomy.tools/calculators/ccd_suitability for camera/pixel size recommendation.
plus
https://astroforumspace.com/best-zwo-ca ... otography/ for camera advice

Wishing you the best.
Terry
Thanks Terry. My currency conversions are pretty accurate, always have been. It's actually more expensive for me to buy from the UK than the US - buying from the UK, from my experience, will nearly always be more expensive than the Australian price. I've bought an item from FLO before - excellent customer service, well packed item and very fast shipping.

I use atronomy.tools, including those 2 links quite a bit! I try to match the camera to my scope in terms of arc second/pixel for under/over sampling and of course, FOV. That's why I picked the 1600mm pro to go with my Esprit 80 (and went with the 80 over the esprit 100). My main love is nebula and that's what really interests me. I really like using PixInsight, it's probably the best application I have ever used in nearly 30 years of using computers.

I'm not familiar with the 3rd link, checking it out now - thank you!

Yes, warranty is an issue and there's no easy way to deal with it. Remember, those US prices include warranty too, which begs the question as to why local Australian prices are so much higher. I am not the only Australian consumer who is unimpressed with local pricing etc, it is a growing problem, frustrating more and more Australians, and making us more and more angry. Many, like me, will even buy from overseas now just to punish local retailers/distributors and take business away from them. Price gouging is not treating customers good, and imho, businesses that don't treat customers good don't deserve to stay in business. That may be a harsh thing to say, but I am the consumer, and it is *my* money.

Clear skies,

Dave


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Re: Back focus for Lunt 60mm TT BF1200

Post by EGRAY_OBSERVATORY »

Thanks Dave.
I have never and will always-never deal with any company who don't give me the respect and courtesy that my dosh and custom deserve.
There have been several who were informed of that, including some of the "big boys" too. Compensation has been achieved by my letting a couple of those know my feelings, which does go some way to accepting their apologises, but that seems rare.

Orion, Bresser and the U.K. distributer/supplier were well aware of that, as none of those have since gotten a penny of some thousands of £'s spent elsewhere recently, as none of those-three had the courtesy and grace to even acknowledge that they were producing/selling sub-standard gear, after a first email to request warranty-guidance. The two manufacturers and/or the supplier could have been successfully sued for a refund, but I've got better things to do...

As for any price-fixing within the Aussie markets, is not something that I can really make a comment on, except of course delays and difficulties in supplying almost anything - thanks to COVID.

If warranties are not included in the purchase-prices, then they should be avoided at any cost... And not to buy a pre-purchase insurance for such items as an extra is not the way forward either. That should be down to the manufacturers and/or seller's to insure coverage of warranty in the event of a return..

I must add Dave, that I live about 20-miles to the East of the Greenwich Meridian line, which would make G.M.T. my obvious favourite time in any case, but as of now, to have to take-off 1-hour away from British Summer Time as "DST" does somewhat annoy me as totally unnecessary and where I have two clocks in the observatory telling me which one to use... Winter-time is just a luxury compared to DST.
The various mounts are always programmed as GMT...

CLEAR SKIES
Terry


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Re: Back focus for Lunt 60mm TT BF1200

Post by dpastern »

Yes, bad retailers do not do the industry good imho. But, I should probably return to the topic at hand - solar, rather than berating sub-standard retailers and distributors. I will say that these pricing issues were always evident, even pre-covid19. It is not a supply issue.

Anyway, I evidently have plenty to learn!

Many thanks for your time, patience and help. It's greatly appreciated.

Cheers,

Dave


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