Hi Viky.... Please forgive me for duplicating a post to you and Trevor, but this is what I have to add to getting a little more out of your Rev50 work.... BTW I think you are doing a great job, and with a couple of additional things considered will take them to the next level..... Take care
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Hi Trevor, and Viky. Please take what you think will help and disregard what you already have figured out.. What I will suggest is start with your 100-300 at 100mm for a milder more manageable mag to start with 2:1 is still way cool.. Be sure 50 is set wide open and set to infinity focus.. Set your main lens to f16 to f22 this will increase your DOF for a little easier focusing.... This range of aperture is essential to get any workable DOF for the shots.. That's a fact.. Finding the bug wide open and hitting focus with so little DOF is very difficult, and the DOF so thin it would be the thickness of a piece of tracing paper, once you close the main lens down in the range of f18 to f22 it becomes the thickness of a piece of construction paper. Start with something stationary to get the feel for it... Anything on a table or counter top will help you get used to the approx working distance and help get you adjusting to how thin the DOF is.... That is where I started getting good practice adjusting to the rig... Keep in mind again your working distance will be under an inch, and focus will be achieved by moving the lens closer too or further away from the subject... Be sure all auto focus features of both lenses are shut down, and forget the focusing rings once set.... Once you get comfortable with this, you will need to get the flash directed right at the end of the lens for good results with the shots... Brian showed an example of a sweet yet simple solution... With external flash mounted to the hot shoe take a piece of paper and form it to attach with tape to the flash unit and be sure to have the paper flaring and directing the light out to the end of the lens, at a slight downward angle from flash to lens.... Cut or end the paper no more than an inch or so past the lens.... This helps soften the light and put it out where it needs to be.... With under an inch of working distance a conventional flash won't squeek in where it needs to be... And the images will usually be far to underexposed without use of a flash...I personally start my camera settings at ISO 200, shutter to 1/320, camera set in manual mode... Flash set to manual high speed sync, and I dial down the EV to 1/4 this is usually close to right, I then fine tune from there.. Usually changing shutter speed by one value up or down.. Viky..... I would like to add this last bit of advice to you to bring out your shots a little more... Lighting the subject with mainly backlighting won't work nearly as effectively when it comes to detail of the bug without blowing out the highlights. It takes the directed light to bring out the detail once again because of the small working distance and the inability for the light to get where it needs to be.. Natural light rarely works with the reversed 50 set up.... I looked at your exif data and as near as I can tell you have everything else dialed in, nicely, you just need to modify your exposure settings when adding the use of a flash unit...... Good luck guys... I hope this was a help... Oh and remember "You asked 
" Here is an example of my settings at work with the first three images.... Ranging from f20 to f25, along with my other stated settings...Take care
https://photography-on-the.net/forum/showthread.php?t=361515
