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IDProjectCategoryView StatusLast Update
0002152SkyChart1-Softwarepublic19-10-03 10:49
Reporteranu Assigned ToPatrick Chevalley  
Status resolvedResolutionfixed 
PlatformPCOSWindowsOS Version7
Product Version4.1 SVN 
Target Version4.2 
Summary0002152: Finite number of star labels on chart? Rigt side of chart remains unlabelled
DescriptionDear Patrick
When i tried to print (presumably IAU approved newly added since i had tried it a long time ago) IAU approved proper names of stars on skychart 4.1.3957, i got right side of chart empty without labels. I had intentionally overcrowded for purpose of having maximum stars and names names so that i can add more which are not approved yet by IAU. Further if i add more things that induce names, e.g. dso default SAC catalog names or custom caldwell catalog, further names from common names displayed on screen and in printed pdf disappear. Even stars like Sirius get unlabelled and right chart is completely blank. Have attached example pdf.
Steps To ReproduceKeep FOV 210-230 deg. RA 6h Dec 0h, setup>Dispay>Labels>common names is on. Auto optimize label position is on. To maximize number of labels, stars> magnitude difference is '0' . Real visual magnitude of stars experimented between 6.5 and 8.5 via Setup> chart, coordinate>object filter>filter stars menu. DSO filter is kept off at first still it yielded blank portion of chart. If i add dso and its labels, further reduction of star names
Additional InformationRef: You had helped me on forum about XHIP being most acccurate.
TagsNo tags attached.



19-07-08 20:12


CdC.pdf (351,914 bytes)


19-07-08 20:18

reporter   ~0005750

Last edited: 19-07-08 20:25

View 4 revisions

Errata: spell in topic heading "right",

Wishing regardless of this issue of completely blank right side of chart, if its possible to export more labels in print pdf when its big in size e.g. A3 or A2, would be greatly appreciated.

Currently in example its kept deliberately overcrowded (7.5-8.5 magnitude limit of chart) but had tried same at various magnitude limits and happens even for mag 6 limited chart display. Anomaly is observed in print as well as display.

Patrick Chevalley

19-07-09 09:23

administrator   ~0005751

There is a hard limit to a maximum of 1000 label per chart in the program.
This is the total number of label candidate, but when "optimize label" is on the program can later remove some label it cannot solve the overlap. The removing process use a priority setting, highest priority is constellation and planet, then bright star and Messier objects, then standard DSO, finally faint DSO, faint stars, asteroid.

But as the DSO are draw first, they can take all the label stock, even if they are finally not draw because of the optimization. So it is important to not try to label too much DSO on a wide chart if you are interested by the star labels.

You can try to disable "optimize label" to see the total number of label the program try to draw.
Then adjust the DSO label setting to prevent too many DSO or other label. When OK you can enable the optimization again.

But remember the optimization can remove a label even for a bright star if it cannot solve the overlap with a same or higher priority label.


19-07-09 10:31

reporter   ~0005752

I tried optimization off. (chart filter mag limit 6.5) It helps but only partially and some names still get missed.

Then i tried by keeping all dso, constellation name labels, and all other labels completely off and keeping only star labels checkmark. Also only common names is kept on.

Still the situation is like when we wish to know all named stars, we have to keep magnitude difference setting to 0 else we tend to miss some faint star common names.

Then the side effect of this setting is that stars which do not have common name also get labelled as flamsteed or bayer id and may be thats why label count increases further exceeding the limit.

current workaround of creating custom cdc catalog from following catalog viable? Will try it.

Patrick Chevalley

19-08-13 09:54

administrator   ~0005844

I make more testing with a chart of 360° FOV, using the default star and dso catalog without filter, and using a magnitude difference of 0 for the stars and 4 for the dso, in this case need about 3300 labels.
So I make a change to allow 3500 labels and this must fix your issue.

Please test with the beta version that will be available after Monday 19.


19-08-14 02:30

reporter   ~0005845

Dear Patrick
Thanks. Will test it and report.

Patrick Chevalley

19-10-03 10:49

administrator   ~0005984

Please reopen if you still have issue.

Issue History

Date Modified Username Field Change
19-07-08 20:12 anu New Issue
19-07-08 20:12 anu File Added: CdC.pdf
19-07-08 20:18 anu Note Added: 0005750
19-07-08 20:21 anu Note Edited: 0005750 View Revisions
19-07-08 20:22 anu Note Edited: 0005750 View Revisions
19-07-08 20:25 anu Note Edited: 0005750 View Revisions
19-07-09 09:23 Patrick Chevalley Assigned To => Patrick Chevalley
19-07-09 09:23 Patrick Chevalley Status new => feedback
19-07-09 09:23 Patrick Chevalley Target Version => 4.2
19-07-09 09:23 Patrick Chevalley Note Added: 0005751
19-07-09 10:31 anu Note Added: 0005752
19-07-09 10:31 anu Status feedback => assigned
19-08-13 09:54 Patrick Chevalley Status assigned => feedback
19-08-13 09:54 Patrick Chevalley Note Added: 0005844
19-08-14 02:30 anu Note Added: 0005845
19-08-14 02:30 anu Status feedback => assigned
19-10-03 10:49 Patrick Chevalley Status assigned => resolved
19-10-03 10:49 Patrick Chevalley Resolution open => fixed
19-10-03 10:49 Patrick Chevalley Note Added: 0005984