Here is the English version of the review, also posted in the following links:
http://www.cloudynights.com/ubbthreads/ ... ll/fpart/1--------------------------------------
LS152 is the largest aperture solar telescope in the market, with an aperture that is only slightly smaller than the largest external filter LS160F. The set arrived in an aluminium case with tube holder and a Lunt 7-21mm zoom eyepiece. I purchased blocking filter B1800 since it is intended for imaging. For visual only, B1200 is good enough according to Lunt website.
The size of this scope is much smaller and lighter than a typical 6 inch refractor and so it does not absolutely demand a very heavy duty mount. For testing, I used Skywatcher HEQ5Pro mount. By comparison, the much more expensive LS160F external filter will at least require a 7 inch refractor. Without a permanent observatory and a lot of money, LS152T is probably my ultimate choice.
Lunt website calls this scope a 'modular solar telescope' rather than a 'dedicated solar telescope' because LS152T is not only suitable for hydrogen alpha observation. With suitable accessories, it can also serve for Calcium-K and white light solar observation, as well as nighttime star-gazing.
The main body of LS152T is no different from a typical refractor. The back side of the scope is fitted with a red component called a hydrogen-alpha module with a 60mm internal filter. It also includes the pressure tuner for adjusting the wavelength.
If one wants to observe in Calcium-K, this module can be replaced by a Calcium-K module which can be purchased separately. If one wants to use the scope for nighttime observation, the module can be removed and replaced by a suitable adaptor. Then one can just add some white light solar observation accessories to view the white light sun.
Theoretically, solar telescopes with internal filter are somewhat compromised in image quality when compared with external filters. The main advantage is their much lower cost. How does LS152T perform?
I first used a Televue Nagler 12mm (about 75x) to view the whole solar disk. The whole sun revealed tremendous amount of details with a resolution that clearly beated 100mm products (LS100T, LS100F) that I had used before. The image was very contrasty in accordance to its bandwidth of <0.65 Angstrom.
When I used LS100T at high magnification (about 100x), I often felt that the image was a bit dim for my taste. With LS152T, using 130x to observe a huge prominence with the Lunt zoom eyepiece, I found that the image was still bright enough for me. My aperture fever has finally been cured.
I went back to lower magnification (75x) to check the uniformity of the image in terms of brightness and contrast. I found that the uniformity was much better than the LS100T that I had used. In fact, as far as I could tell, I didn’t notice any non-uniformity.
Then I tested its performance in photography. Using a DMK camera, the first thing that I noticed was the much better uniformity of the image, confirming my visual impression. The large aperture allowed me to image at very large magnification. With LS152T's focal length of 900mm and using a TV2.5x powermate, I could image a prominence with an exposure time of less than 1/100s (Gain was about 850.) This helped to combat the poor daytime seeing. The focuser of LS152T is the feather touch focuser from Starlight Instruments, allowing very accurate focusing which is important for photography.
Overall, I find that LS152T is an excellent solar telescope with internal filter without obvious compromise in image quality. It is a superb instrument if one is very interested in high magnification observation and photography but with a limited budget.
APM 80/480, SW 120mm Equinox, C8, Obsession 18"UC with Argo Navis & StellarCat
Lunt LS60T/CaK, LS152T with DSII
DMK31AF03, DMK21AF04, DBK21AF04
Mark V Binoviewer, Ethos (3.7mm, 6mm, 13mm), 19mm Panoptic, 5mm TMB mono
http://www.imsc.edu.hk/pages/astronomy