2x magnification

I currently own a Nikon D7500 and a nikon 105mm f2.8 micro VR that is 1x magnification and I want to go a step further to 2x magnification with the same image quality but just increased magnification. Preferably just add on to the front of the lens.

Thought of extensions tubes but will lose a lot of light.

Thought of close up lens filters but will lose image quality.

Don't want to get a laowa because I would find it irritating to keep switching lenses. Sooner or later will just use 1 and stick to it and forget about the other.

Any suggestions will be helpful because this has been my own issue for the past 4 months

Jason Yao wrote:

I currently own a Nikon D7500 and a nikon 105mm f2.8 micro VR that is 1x magnification and I want to go a step further to 2x magnification with the same image quality but just increased magnification. Preferably just add on to the front of the lens.

There's no "add on to the front of the lens" that will let you keep your lens's VR or it's superb optical quality. You need about 7 diopters of "closeup lens" to get the 105mm down to 2:1, and that means the closeup lens would be almost as strong a lens as the 105mm f/2.8 itself, and it would account for about half the optical quality. It would have to be almost as complex as the 105/2.5 itself to get the same image quality. 2 or 3 element "achromat" closeup lenses are not going to make the trip.

Thought of extensions tubes but will lose a lot of light.

Not "a lot", but often enough to be annoying. You'll also lose your VR.

Thought of close up lens filters but will lose image quality.

Yep.

Don't want to get a laowa because I would find it irritating to keep switching lenses.

Why would you have to keep switching lenses? The Laowa 100mm f/2.8 focuses all the way from infinity to 2x magnification. If you don't mind the loss of VR and AF, you can use it as an alternative to the Nikon.

Sooner or later will just use 1 and stick to it and forget about the other.

Yep.

Any suggestions will be helpful because this has been my own issue for the past 4 months

Richard Dutton wrote:

Yes you are going †o lose light whatever.

You should be able to get good image quality certainly in centre frame with a good achromat. The Nisi 58mm is easily available and is 5 dioptres. Use a step down ring 62 to 58. You should get near to 2:1 with that according to the calculators but in my experience they overestimate and probably 1.7:1 is nearer to what you will get.

The Raynox DCR-150 ( 4.8 dioptres ) and DCR-250 ( 8 dioptres ) have excellent image quality. They are three element designs I think. Lose yet more light.

You can always get more light. What you can't get easily is more image quality and more working distance.

You need somewhere in the near vicinity of 7 diopters to get a 105mm Nikon to go to 2:1. The reason you don't need 10 diopters is that the lens shortens its focal length as it focuses closer. At infinity, it's a 105mm lens with its rear node 105 mm from the sensor, but at 1:1 it's more like a 70mm lens with its rear node 140mm from the sensor (magnification = (140mm/70mm) - 1 = 1).

You're stuck with the 140mm, that's internal to the lens, so to get 2:1 you have to shrink the 70mm to  46.7mm (140mm / (2 + 1) = 46.6mm). That's 1000/46.7 = 21.4 diopters. The 105mm which has shrunk to 70mm is about 14.3 doppters, leaving you 7.,1 diopters short of a full load.

The problem is that, when two lenses go walking, the stronger one does the talking. In other words, the one with the most diopters dominates the image quality.

But in this case, neither lens really dominates the balance. The 105 at 14.3 diopters isn't really that much stronger than the Raynox at 8 diopters. So your image quality is about half one, half the other. And "the other" is a simple 3 element/2 group achromat with a little bit of field flattening. It's nothing like the optical quality of the 105mm f/2.8 VR with 14 elements in 12 groups correcting field flatness, barrel, pincushion, spherical aberration, lateral and longitudinal chromatic aberration, comma, etc.

You're also dropping the working distance of 140mm from the front node (about 100mm from the front element) down to about 70mm from the front node, or around 45mm from the front of the Raynox.

So you've really killed both the image quality and the working distance with a closeup "filter".

Some other views using TC's instead here

Lots of other threads about getting higher mags from the 105 on this and other forums e.g. this thread

The optimal solution is a lower-power closeup lens (less destructive of image quality) and a short extension tube. Just working the numbers in my head, a 24mm tube and a 3.3 diopter closeup filter will hit 2x with a lot less loss of image quality or working distance.

I use that filter on my Sony FE 90 mm lens nearly every day.  The image quality is excellent and I get a bout 1.8:1 magnification.  With the 105 lens you should get very close to 2:1 magnification.