According to our guide CY itself is very uncommon there but Berger's and Eastern Pale are common. The closest I can see in Collins is probably male Danube (because of the low amount of spotting on the forewing underside) which is common in romania but not so much in the mountains away from the river system.
Hi Owen. My best bet - disappointingly, probably - is clouded yellow for both (first picture a male, second a helice female).
I hope I'm wrong, but for what it's worth, here is my logic:
The first one appears to be a male, from what seem to be the very solid dark borders. I don't think it's a male Danube clouded yellow because the one submarginal spot we can see appears to be quite dark and well defined, and the colour seems muted for this species. I don't think it's Eastern pale clouded yellow because the overall feel seems wrong - wrong shape, wrong colour tones. I haven't seen Eastern pale clouded yellow myself but I have seen its close relative in India (formerly considered the same species), the Nilgiri clouded yellow, and these differences in feel were obvious.
For the second, it's obviously a white form female. From what can be seen of the upperside colouration showing through, it is certainly not Berger's or pale clouded. Now Danube clouded yellow and Eastern pale clouded yellow do both have white forms, but this does look a lot like helice and in the absence of evidence to the contrary, I'd go for that.
I'm surprised your guide says clouded yellow is very rare there. It is a notable migrant and can turn up pretty well anywhere in Europe in summer.
Thank you Guy, no it's not disappointing, we saw lots of the group over the trip so it's just trying to file photos. They definitely didn't look out of the range of CY I've seen in the Uk (or in spain for helice as i've not seen that form in uk), I guess my guide was mistaken, he was very good on butterflies but was a native of the black sea region rather than carpathia
