Es schien nicht gerade die Sonne. Die Sonne schien gerade.
any difference in the meaning between the 2 sentences?
The first sentence is a bit colloquial, but definitely used in German. The best translation I can offer is The sun was not exactly shining, or in order words, there was anything but sunshine. This construction is sometimes used to form something like a 'polite negation', where you don't want to stick the negation in somebody's face.
- Wie war der neue Bewerber?
- Er war nicht gerade jung ...
That is the complete opposite of the second sentence which means The sun was just shining at this moment.
Regarding the first example - Yes, it's the same for me as a native German speaker: the first example sounds weird. Additionally I wouldn't use this construction/expression in connection with the sun. Maybe because the sun simply shines, there are no degrees. Same for light: A lamp is on or not, a sentence like 'Die Glühbirne war nicht gerade an.' does not make any sense. But with another word order, it makes sense: 'Die Glühbirne war gerade nicht an.' means, that the lamp was not on a moment ago, but now she is on.
But it is common to say: 'Das Wetter ist nicht gerade gut.' The meaning of this construction is, that something is rather bad, it is - as territades wrote - a polite nagation.
The second example sounds a bit weird, but the sentence is ok. The meaning is different. We often use this construction with noch: As the verb is in the past tense the sentence means, that the sun shined till just a moment before, but actually she does not shine (we don't see her light). Ex.: 'Gerade hat die Sonne noch geschienen!' or with your sentence 'Die Sonne schien gerade noch.' Btw. the expression 'gerade noch' could have also another connotation. In the sentence 'Der Eintopf war gerade noch gut (genug).' we express, that the soup is not as good es expected, but not bad at all.
The second example sounds a bit weird, but the sentence is ok. The meaning is different. We often use this construction with noch: As the verb is in the past tense the sentence means, that the sun shined till just a moment before, but actually she does not shine (we don't see her light).
I disagree with that. I dont consider this weird and cleary without connotation. It might be rare to use this sentence like it is, but something like this is a realistic scenario.
Youre telling your friend about your weekend trip to Prag. He asks Wie war das Wetter am Samstag? Du antwortest: Es schien die Sonne. There is no connotation and its not weird either. Your interpretation that makes it negative comes by adding more words (and with that information) to the sentence, specially something like gerade noch changes it.
And I disagree with you :-) May be it is due a different education level or simply the age difference or we live in different regions in Germany. So it may be, we both are correct.
If I would tell my friend about the weather during last weekend or in the near past somewhere, I would rather say "Die Sonne hat geschienen." In my region, we don´t use simple past that much (anymore?). For the example sentence of the OP, we would rather say "Die Sonne hat gerade geschienen." (as I mentioned before). I would never ever say: "Es schien die Sonne" or "Die Sonne schien." and I would never say: "Die Sonne schien gerade."
Edit: I tried to lead my colleagues to tell me something about weather and sun (I didn´t mentioned about this thread and I tried to avoid using the structure by myself). All said "Die Sonne hat geschienen." Maybe it is different in other regions in Germany, I don´t now.