香港天文論壇

Dear Mr. Chan Great to see your reply. Thanks a lot. I am a newer in this field, and i just heard of my friend said you are an expert in make telescope. I am studying university and my team is quite interested in making a telescope as our final year project, actually I am interested in astronomy an...

May I join?
1. Wah!
2. 豆豸苗
3. universe24
4. chrislichi
5. Tarepanda
6. 天狼星
7. Edward (vr2xsc)
8. cyf
9. Martin馬田
10. PaulNg
11. layanata
(12. BKSo)

Afocal projection
Telescope: 76mm F9 Newtonian Reflector
Eyepiece: 20mm H, 4x in camera
Camera : Sony DSC V1
F4 1/10s ISO 800
23 Frames stacked

I found this when reviewing old photos

This is the last photo...

photo #5 86 frames stacked
photo #6 150 frames stacked

I notice a dark region in the lower left of photo 2 and 3. The western (lower right) part of this feature is known as Mare Frigoris, but not the eastern part.

SY Lok 寫:那為什麼我影果個太陽, 見唔到黑子呢 ?

I think the main problem here is the floppy disk. This filter tends to blur image and reduce contrast. I used another filter for my IR Moon series.

64 frames stacked

Just snap-shooting at TST...
Infrared image
DSC V1 F2.8 1/30s ISO 100
Used 1 layer of film and 1 layer of floppy disk as filter.

80 frames stacked

Wah! 寫:如果用大口徑的望遠鏡,唔知會唔會見得到紅外木星與可見光木星的不同處呢?

Sure. Aperture still rules.

180 frames stacked

Normal solar filters are designed to block 100% of IR and UV. I am not sure if enough IR leak through...

For the Moon, you would not see much difference between images in visual spectrum and IR spectrum. I argee that both visible and IR moon look similar in general, but some local features may look different. I still have many clips covering other parts and we can study them in this forum. Try IR band...