Two images are attached.
Both were photographed in s Thialand on the Malaysia border.
T. ultra is relatively common in the area.
T. waterstradti is scarce in the area.
I think the first image is likely T. waterstradti, but I am unfamilair with the taxon.

The grouping of the spots on the forewing into groups of 5 and 2 seem to initially indicate T. waterstradti for both these images.
But I think the spots on the hindwing are too large in the second image, so I think second image is T. ultra.

Comparing the first image to the few images of T. waterstradti I can find in the literature and web, indicates the smaller spots in the hindwing, as well and the general layout of the spots in image 1 seem to match T. waterstradti.
I also note that the forewings on image 1 appear shorter and more rounded than on image 2. A differntiating feature?

However, I find an image of female T. ultra on Yutaka's website that has groups of 5 and 2 spots in the forewing. Though hindwing spots are still larg(ish) and evenly sized.
This creates confusion.

One thing I did notice about the individual in image 1, was its small size.

Is waterstradti smaller than ultra? I can find no size measurements anywhere.
Feedback appreciated please.

Image 1.
409A0764.JPG

Image 2.
b7205 Ultra Snow Flat (Tagiades ultra) 195 m - TH (Bang Lang - Chula 9) 01.JPG