You did not indicate which version of MEP that you are using. If 2014Plus or Premium, then see pages:
27-28 and 98 for handles and transparency
See the first image below. I did not do all of the steps as most are just repetitions.
Simply insert the first image, click on it, drag the centre handle down to inscrease transparency, which will make the image partially faded. Set it to what you want. If you want it to fade in, then also drag the left fader handle to the right.
Insert your second image, do the same but with less transparency, that is, do not drag the handle down so far.
Insert your video, do not adjust the transparency.
Insert fourth and fifth images and do as above. You can copy the effects from the first 2 images and paste them onto the 2 right images if you want them identical, or copy and paste the images with the effects if they are exactly the same.
I don't think that you will like the result because all it does is make your image darker. You might want to try using the Video Effect, Sharpness, Artistic blur instead, or a combination this with a partial fade as above. In the image below, at the right, I did an artistic blur, then added an oval mask and changed the size to suit what I wanted. The result is in the second image below. The mask feature may not be available in the regular version, only in Plus or Premium. If you have either of these, see pages 138-139 in the manual for masks.
If you can do masks, then play around with them to get the effect that you want. Look at some of the tutorials to see how to apply them.
After preparing my reply I saw that John has pipped me to the post but I'll post it anyway in case it helps further:
If you really do want this 3-object section of your video to start at 50% transparency (rather than zero) then a quick and intuitive way would be to export the section I've shown, re-import it, and trim a little off the start and end.
First of all, thank you for your answers, both of you! But I'm affraid I could not describe my plan clearly. I had no time, when I wrote that post. Very simplified descripton. I would like to overlay different time created snapshots onto video. Visibility depend on time stage of video. I made new project graph. I attach below. There is a moving object on a video, and I would like to appear it in different phrase.
You need to upload a short example, from wherever you've seen this sort of video, so that we can avoid spending further time answering misunderstood requirements.
Also, what is your experience level? Presumably you do understand very basic aspects, such as fading, adjusting overall transparency, overlapping objects of different durations on separate tracks, and exporting?