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I may have already mentioned that I am brand new to solar imaging so my editing skills leave a lot to be desired, this is something I am working on right now, taking advantage of the cloudy weeks. Here is a re-edit - I have the B500 (5mm) blocking filter, with the B600 or above, full disc is possible with the 290-MM and the Lunt 40mm. |
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This image was taken on a cloudy day so please excuse the softness of the image, the banding artefact is something else I need to sort out, taken again with the 290MM but with a 2 x Powermate. Precise focussing with the helical focuser once you pump up the magnification gets harder but it is possible, the helical focuser will not move once its set and it is smooth. |
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Tico's original question was is the Lunt 40 worth it. My answer is yes. After several months of learning the ins and out of capturing and processing solar images, I can say the Lunt LS40 with the B600 stop is providing satisfying mages. This composite image was captured with an ASI174mm and a 2.5x Powermate with an ASI tilt adapter on a SolarQuest mount. The top and bottom halves were captured with SharpCap using the seeing-triggered capture tool, inverted andf stretched with ImPPG, merged with Lightroom, and colorized with Photoshop. A bit off topic, but I will enthusiastically recommend the SolarQuest mount. Eight AA batteries last about 8 hours if you remember to turn the mount off after a session. With the camera powered by my laptop, I can go anywhere and be setup in minutes. (An ISS solar transit Monday afternoon is on the calendar.) Of course, with AC power the mount will run all day and I've done that. After 7 hours the Sun was still dead center thanks to the optical quiding. I'll also enthusiastically recommned the SharpCaps seeing-triggered capture tool. It tracks variation in seeing based on contrast, you specify a trigger point (I use about 3 standard deviations), and then wait for it to collect only the very best frames. Then, if you use quality selection in PIPP and Autostakkert!3, you end up with the best of the best, for the final product.  |
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Wow!! And for visual observations? How is..? Thanks. Tico |
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And for visual observations? How is..? Honestly, I can't answer that. When I first got the scope I used a 7-21 zoom to learn how to use the focuser (I upgraded to the FeatherTouch) and etalon tuning. But I was intent on the mechanisms and not the view. As soon as I more or less knew what I was doing I put the camera on it and haven't looked through it again. |
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Wow!! I'm not a visual astronomer but what I saw in a 30mm eyepiece blew me away, really! I could not wait to get the camera on there. |
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It is difficult to evaluate a solar scope with inverted, processed images. It would be helpful to post unedited images without a flat. Some images on this thread are off band. To tune a scope, adjust to get the darkest filaments and brightest plage. There is a histogram method but in my case the eyeball does a better job. It takes time to get a feel. It is much easier with an eyepiece. I am considering purchasing this scope to use as a portable set up on an alt/az mount Here is a website that will help to let you know what you should see when on band https://gong2.nso.edu/products/tableView/table.php?configFile=configs/hAlpha.cfg |
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| This is a very relevannt comment. I'm still a starter with solar imaging and I was shocked about the fuzzy data I got out of my Coronado double stack in my first attempts. There is some learning curve to master and what you get out of the scope in first place has nothing to do with the published images here. |
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This is really interesting. I've also been thinking about the Lunt 40. But I can't decide if it would be better to get a Quark Chromopshere eyepiece instead and make use of the big aperture of my APO (150mm) to get more definition. Only problem is, that would be an expensive option as the ERF for that aperture costs about £1k! I'd be mainly doing AP not visual Any thoughts on the choice between Quark + 150 and the Lunt 40 ? |
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I bought a quark, drove myself nuts with it, and sold it. I subsequently have learned that they seem to have a quality control issue and there are some good ones and some bad ones. Regarding the 150mm...keep in mind that as aperture goes up seeing becomes more and more of a problem for solar and Ha. I wasn't entirely thrilled with the Lunt 40 when I first got it, but as I've learned more the scope has improved...if you catch my drift. There's no question Ha is expensive, but the Lunt 40 is a good value and probably the least expensive way to get into it. |
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Stuart Taylor: You can use a cardboard iris to reduce the aperture of your lens until an energy filter is no longer needed. (I think you only need it from 80 mm upwards.) Then you still have a larger aperture with better resolution, and you can also use the Quark with another telescope. |
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Olaf Fritsche:Stuart Taylor: I think Olaf means that if you use a cardboard stop and Quark for solar, the resolution will be only as good as the size of the hole. But you do have better resolution in white light solar with a filter and full aperture for DSOs. |
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Hi, I have one Lunt 40mm...what solar telescope!! IT is very very good solar instrument.... I recommended this cute telescope. Best regards, |
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Tom Harnish:Olaf Fritsche:Stuart Taylor: Perhaps I have not expressed myself clearly. Therefore, I will try again: - With an H-alpha filter like the Quark or the SunDancer II, an energy filter is only necessary at larger apertures. According to Baader, the limit for the SunDancer is 80mm. - For larger telescopes, you can reduce the aperture with a piece of cardboard instead of the energy filter. (Baader website: "An additional D-ERF energy protection filter in front of the telescope is necessary only on telescopes with more than 80mm aperture; alternatively, the telescope can also be stopped down to 80mm with an optional diaphragm in front of the lens.") - 80mm is twice as large as 40mm on the Lunt40. Therefore, the resolution should be higher. - Also, you can put the Quark or SunDancer into another telescope (e.g., a travel telescope) and then use it to observe in H-alpha. |
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Olaf Fritsche: Well said. Makes complete sense. |
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The Lunt 40mm is a risk free purchase:
The Lunt 40mm is also a gateway drug into solar, my focus is imaging. Although they may be accurate, I don't see the point in some of the comments been said here in terms of peoples images, off-band, inverted images and so on, at the end of the day if people are enjoying their scope then isn't that what matters? What you see through the eyepiece of the Lunt 40 is incredible and imaging with it is so much fun. I only have the B500 blocking filter so with the ZWO290MM, I need to do a 2 panel mosaic (image included here) Not too difficult to do but a B600 may be a better choice for full disk and small sensors. Anyhow, I have had this scope for a couple of weeks now and 90% of that time its been cloudy, there will be more opportunity to tweak the use of the scope and further develop better and more sensitive editing skills but I love the Lunt 40 so far. As I mentioned, this scope is a gateway drug, you will crave for more close up shots, the Quark is an obvious choice but I do believe that a dedicated Lunt will produce better results in the hands of some people. In my case, the Quark could be the next logical step as I already own a stable of Esprit's but at this point I am trying to improve my images using a 2x Powermate and the Lunt 40. Focusing is more difficult as you zoom in, a motorised focuser would be handy and I have just built one for the Lunt 40mm, simple bracket with a ZWO EAF mounted to it and a belt drive system to turn the helical focuser, tested yesterday and this image was the result in reasonably poor seeing, lots of cloud about. Being able to move the helical focuser remotely and in micro-steps is a game changer in my view. The whole contraption cost me $10 to make as I already had a spare EAF lying around. The other option of course is a feather touch etc etc but we are talking big $$$ now. The sun has proven itself to be an amazing target, always changing, always interesting and the Lunt 40 has shown me this, In summary, just get the Lunt 40 and have some fun.  |
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The Astro Garden: The 2x Powermate is a 2"device, no? How do you fit it to the LS40? I have/had the 2.5x Powermate but had lots of Newton Ring issues with the ASI174MM. More or less solved the problem with flats and a tilt adapter, but have gone back to a garden variety 1.25" 2x Barlow. |
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Tom Harnish:The Astro Garden: Hi Tom, I am also getting strange 290MM banding (its not that bad but its there) with the 2 x PM and I think that it must be the Newton's ring issue as well, the tilt adapter is a must, which tilt adapter are you using? If you remove the 1.25" adapter from the Lunt 40 eyepiece and then put on a standard M42-F to M48-M (I am guessing sizes here) enlarger ring then you can mount the 2" power mate directly to the Lunt 40 eyepiece. Then, directly mount your camera to the top of the Powermate which I believe should be M42. Apologies, I am not in my observatory at the moment so can't measure anything. Attached pic with the setup and my DIY motorised focuser thingy that now needs a paint job - Cheers, Bill.  |
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Tom Harnish:Olaf Fritsche:Stuart Taylor: Olaf Fritsche:Tom Harnish:Olaf Fritsche:Stuart Taylor: It's fine Olaf. I understood you perfectly well. Thanks One question I do have though. Why does one have to buy a hugely expensive ERF to cut down the intensity? Why will a normal white light filter made of Baader solar film do the job? |
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Another crop-rotate from the original full disc image with prominences as a feature. I feel that the motorised focuser allowed better focus tuning. Lunt 40mm & ZWO290MM. |
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The Astro Garden: Your EAF arrangement is awesome. I have one on my DSO scope and love it, especially since the ASIair uses it after a meridian shift or temperature change. (ASIair is the best astronomy invention since the telescope! Just finished collecting 27 hours of data for a composite of the Heart Nebula (IC1805) and didn't lose a wink of sleep). I bought the Feathertouch focuser and wish I hadn't. It really isn't that much more precise and you have to fiddle with the friction knob to keep the focus tube and camera from slipping. Someone asked what tilt adapter I use. I bought the ZWO device and it worked as advertised but the Newton Rings are a real pain. Sent the 2.5x Powermate and tilt adapter back and am happily using a run of the mill 2x Barlow with no problems and no discernible difference in the image. That said, your proms are awesome; I haven't achieved anything like that with or without the Powermate. Always more to learn. |
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The Astro Garden: Really inspiring stuff. Looking at getting the ls40 with either the 600 or 1200 BF. Which ZWO camera would you recommend. The 178 or 290 mm? The pixel size is similar but the FOV of the former is larger I think. I'm sure someone will soon come up with a 3D printed mount for the EAF on the LS40 although I really like your improvised solution. Cheers, Des |
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Looking at getting the ls40 with either the 600 or 1200 BF. FWIW, I bought the B600 and use an ASI174MM which is capable of 128fps at 16 bit 1936x1216 and 400 at 8 bit 640x480, That speed helps a lot with poor seeing and when you're trying to catch a transit. That below timelapse image is every 10 frames extracted from a SER video. Lunt LS40/B600, ASI174MM, 2X Barlow, SolarQuest mount. Captured with sharpCap 20220124-2320 from Solano Beach CA  |
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Can someone please elaborate a bit on the Newton ring issue when using a camera in combination with a barlow lens mentioned above? What is the mechanism that causes this phenomenon and how do you get rid of it? Could this explain the uneven illumination I see in this image? Best regards Wolfgang |
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One question I do have though. Why does one have to buy a hugely expensive ERF to cut down the intensity? Why will a normal white light filter made of Baader solar film do the job? ERF filters and normal ("white") solar filters have different tasks and properties: - A solar filter blocks the entire spectrum, which is why the image of the sun appears white. The rest of the light in the range of H-alpha is too weak behind this filter to be seen. With this filter, we are looking at the bright photosphere of the Sun. - An ERF (Energy Rejection Filter) is designed to prevent too much heat from entering the tube, which can otherwise cause turbulence and accelerate the aging of the ethalon of the H-alpha filter. It absorbs or better reflects a wide range of the spectrum to do this, but it lets light through around the H-alpha wavelength so we can see something. With this filter, we look at the not so bright chromosphere of the Sun. Therefore, to observe the chromosphere with the Quark or other H-alpha filter, we must limit the amount of incident light. There are two ways to do this: - A small aperture up to 80mm. - Or for larger apertures an ERF. More detailed information (including advertising for their own products) is provided by this page from Baader: https://www.baader-planetarium.com/en/blog/tips-for-choosing-an-energy-rejection-filter-for-h-alpha-observations/ |
