Coupling reverse lens with zoom lens

Jason Yao wrote:

If coupling reverse lens works to get high magnification, for example, attaching a reversed 50mm to a 105mm lens will give you a 2x magnification.

Correct.

Couple the lenses, set the focus on both the front (reversed) and rear (regular) lens to infinity, and tape the focus rings so they can't "drift" when you point the lenses up or down.

Set the aperture on the rear lens wide open, then set the aperture on front lens for the desired compromise between resolution and depth of field. Note that this is backwards from what the people who say "the front lens is a close-up lens" will tell you. They're wrong and I'm right. Never forget that.

You may have to experiment with that to get comfortable.

Focus by moving the camera towards or away from the subject, or moving the subject towards or away from the camera. Do not touch the focus rings on the lenses: make sure they're both stuck securely at infinity.

Then adjust the aperture on the rear lens to control the compromise between flare and vignetting.

What if you add a reversed manual zoom lens thats 35mm-50mm to the 105mm. Will it give you 2x magnification and 3x magnification?

Yes.

What are some drawbacks other than weight?

High distortion, poor corner performance, more flare, and vignetting.

Will it affect picture quality?

Yes.

If it comes with more advantages, where can I buy a male to male adapter?

The device is called a "macro coupling ring".

I'm currently situated/living somewhere in Southeast Asia.

I'm in the United States, and I buy things from B&H in New York, ProCam in Michigan (It's close, so I can go in and shop) and from eBay and AliExpress, mostly from Chinese suppliers.

For example, here's a typical coupler on eBay, shipping from China. I don't know what size you need, so I picked a fairly common 67-72mm.

https://www.ebay.com/itm/153561827018

I can only guess where you'd try in Southeast Asia, but eBay and AliExpress are probably good starting points.

You should also buy some "gaffer's tape", a kind of "harmless tape" used by photographers for all sorts of things. Once you get your lenses set, you can use the gaffer's tape to hold down the focus rings and zoom ring, otherwise it may drift when you point the lenses down.