At former presentations of cacti fields by few visitors from Mexico I frequently noticed that the shootings from deserts brings out bad disappointments over the pictures. They often look faded and too contrasting. This should be expected because non expert travelers photographed mostly in very sunny places with very, very strong light and the surroundings was waste and colorless. The shadows said me that they had the sun mostly right above their heads.
Actually, the shootings of very sunny themes in very light and burnt landscape should be done very carefully, otherwise the results will be dull, almost black-white looking snaps. You cant change the time of day so you have to be watchful, as more as on exposition, on good angle of lens regards on direction of sun rays. With good choice of your position, you create the shape of cactus with right quantity of shadows rather as making a frontal shot. With game of shadows, you can move the result of contrasts and forms from one side of picture to another and put the stress in best position in picture.
The upper picture shows the trouble of strong contrast which on right picture disappears. The shadow behind cuts the form of cactus out of grass and the inclined direction of apex makes the picture more dynamic.
Pretty big and dangerous spined green balls of G. achirasense grow in silicate gravel, mostly hidden in shadows of low grass. But they still, though exposed to full sun, were not damaged. They were in full vegetation, what can be seen also from new fresh growth of new spines on apex.
The shape of Gymnocalycium achirasense is quite different of other Gymnos which are in this part of Argentina more flat and less spiny. Dense jutted spines reminds more to big Notocactus submammullosus which should we found on that field but we searched for it with no success.
The pastures are flattening to inland side but between wide grass patches big cliffs still push out. As more away of road you go the less stones disturb the monotonous of country. The rock bulks looks like someone put them on there very clumsy.