由 willis » 2011-05-31, 23:06
David 寫:willis 寫:My gamma was not set properly. The photo can be compared with ur LS75F photo. There are room for improving the photo. But it is a good practice to exercise the techniques involved.
What are your tricks in solving the uneven illumination problem?
I use PS to do the mosaic. I failed several times because:
1. The sun was covered by running clouds even they are thin. So very good sky condition is needed. No clouds.
2. Do everything quick in order to ensure the constant brightness of the sun during imaging. I just use 100 frames per video.
3. Stack the video clips with the same set of wavelet theme & procedure.
Even step 1, 2 & 3 are ensured. The mosaic produced by PS is uneven. But PS produced different layers with mask. These are the entry point.
1. Pick the direction with best uniform illumination. For example the top of the sun disc.
2. Activate the nearby layer
3. Tune the brightness until the boundary become invisible.
4. Activate the next nearby layer and repeat 3 until the whole disc become uniform.
See the attached failure example!
- 附加檔案
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- LS80T_DMK210009 11-04-26 Mosaic.jpg (273.99 KiB) 被瀏覽 11054 次
Tak FS60C, APM-LOMO 80/480, APM-TMB 105/650, SW Black Diamond 120ED, Borg 125SD, SW 12" Dobs , Lunt LS35T, Lunt LS80T
TMB Super Mono 4mm, Pentax XO 2.5mm, Baader Planetarium 8-24mm, Nagler (2-4mm, 3-6mm, 13mm), Ethos (3.7mm, 6mm, 10mm), Explore Scientific 100º (14mm, 20mm)
DBK 21, DMK 21, DMK 41, DMK 51, ASI 178MC
Nikon D810A, Canon 5D II, Fujifilm X-T10