When I started my blog, I said that would keep it simple and use photos to show what I was talking. I will leave it up to you to research the finer details, as in using the software. My purpose is to show you that it can be done. If I can do it, you can do it.
So here is the question? How do you get two objects with different depth of fields. Simple, using a tripod, take two shots of each object and then combine them in a “focus stacking” program such as Helicon Focus. Here is an example. I use Lightroom and Photoshop to do my focus stacking. There are other programs that do the same thing. One that comes to mind is Helicon Focus. Click Here for a free trial. Do your research.
To get this shot really good, you need to take more than two shots. You need to take a shot of the space between both bolts and the closest bolt is a little soft on the lower left side. But you get the idea.
Focus Stacking comes in real handy when photographing insects and flowers on a macro level. When your really up close, it is almost impossible to get a well focused dragonfly front to back. Sideways yes but front to back very hard. Ditto for a flower. One part is in focus the other is out. Very frustrating. The best way is multiple shots of the flower front to back, left to right. I usually shoot in quadrants, starting from the rear and work forward or starting in the foreground and work my way to the back. Lastly, you need a tripod period to do a good focus stacking shot. Click Here for a more detailed explanation of focus stacking.