Stack Shot Macro Rail vs Software
I am fairly new to macro photography and am having trouble increasing magnification and stacking while maintaining the same frame around the subject. Here is a list of my equipment:
Canon 5DMkII - 100mm 2.8L - 2x25mm Canon 1x36mm and 1x20mm Kenso extension tubes - Beseler copystand - Macbook Pro - Helicon Focus.
When slide down the bracket on the copystand to fill my frame with the part of the subject i wish to capture (in this case just the back of a beetle) and focus in on the closest part, then when i either turn the focus ring in the lens or use the buttons in the software to bring the furthest part of the beetles back into focus my frame gets much larger and contains almost the entire beetle instead of just the back. The result is my stacked shot has to be cropped significantly and i need the entire frame filled as i am making 36" prints from these shots.
However if instead of changing the focus on the camera i simply move the bracket on the copystand a fraction the furthest focal point comes into focus without changing the frame hardly at all.
Does this mean that i need a StackShot Macro Rail or am i just doing it wrong.
P.S.This is getting expensive!