stopmotion in video editor: how can you adjust the duration of each image (photo)?

hello everyone,
first of all: i am totally new to blender and i just successfully worked my way throu some of the tutorials for the basic usage of the blender video editor.
i now tried to import a stack of images (photos), which worked fine. but now i wanted to adjust the duration of each photo, because now every photo lasts exaclty one frame. my goal is creating a 24fps video that has a normal video sequence (importet from a 24fps video file) and after that a short stop-motion-clip (from photos) but with each photo lasting more than one frame.
i figured out that you can separate the strip into each one strip per image and change the duration that way, but is it possible to keep the strip as a whole thing, where you could change the image duration multiple times (e.g. for adjusting/testing)
thank you very much

If they are just individual single images, not a proper image sequence, select them all and make a meta strip (Ctrl+G)
Then select this strip and Add / Effect Strip / Speed Control
Select the speed control strip and press N to show its properties. Select Effect Strip / Use as speed tickbox. Set the speed factor and if < 1 to slow the sequence you’ll have the drag the end of the original strip to show all the images at the extended length.

Thank you very much for your help, that is exactly what i needed!