www.astrocafe.hk

I tried several times, but failed. This is the first time, the image looks decent.
LS80T, DMK21, EQ3Pro, mosaic of 6 panes

不錯，略有LS75F下單張日面的風範

viewtopic.php?f=15&t=952

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.

我要強調的是 One-shot full disk

不如等什麼時候出 DMK51

Good shot

社長 寫:我要強調的是 One-shot full disk

不如等什麼時候出 DMK51

我真的在等！

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?

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!

Is there any objective measurement of the luminosity in photoshop of the various mosaic photos?
Still find it difficult to use naked eyes to judge at which point the boundary has become invisible.
Maybe I have a pair of bad eyes ...

Yes, there is luminosity measure in PS. One needs to select an area, the mean, standard deviation and median can be measured. But it is hard to judge solely from the values that different part of the solar disc's luminosity is non-uniform.

Nice shot!
好想念這個太陽～