Now in order to use the Contax G 21mm and 28mm lens you'll first have to let go of the idea that cutting off the legs of your 21mm and 28mm Contax G lens will ruin them and the value of the lens. You will only have to cut 5mm from the tip of each leg just so it clears the sensor so it's more like a haircut than a surgical procedure.
Here's what you'll need:
Tools:
- digital caliper or metric ruler
- Scotch Blue Painters Tape
- small hack saw with fresh blade
- small file
- X-acto knife
- damp paper towel
- Metabones Contax G to M 4/3 adapter
- m4/3 lens cap
Directions:
- Use the Scotch Blue Painters tape and cover the entire rear of the lens except the legs. You want to especially cover inside the cavity of the lens between the legs and the rear optic. Fold over a piece of tape and roll it so that the sticky side is on the outside. Squish the little piece of tape down between each leg and lens. This is the area that is vulnerable to getting any debris so you want to make sure this crevice is covered up. Make sure you do not tape the black leg protectors!
- Also, make sure to double up some tape on the rear optic where you will be making your cut. Basically, in case you use excessive force as you are cutting if the blade goes through, you will only cut tape and not the lens. You do not want to hacksaw the rear optics of your lens.
- Using your digital caliper or metric ruler measure out 5mm and use an X-acto knife to mark the 5mm measurement on each leg. If your digital caliper can lock a measurement, lock it to 5mm and mark the top the measurement starting from the very tip of the leg. Make sure you mark off both the right and left side of the leg.
- Now using the straight edge of your ruler or digital caliper, line up your two 5mm marks for each leg and score your cut with the X-acto knife. Do this for each leg.
- Now take your small hack saw with a new blade and line up the blade with the scoring mark. Firmly hold the lens, take a deep breathe and hold and concentrate as you apply pressure and move the blade back and forth slowly in a straight line. You will start to create a grooved slot. Take your time, applying pressure to the leg. If the blade binds, move it just one direction and carve out that groove. Once you get to the end, keep the pace steady and soon the leg will be cut off.Do not go fast, you will make a mistake and damage the lens!
- If you have a small file you can finish off the cut and round off the sharp edges of the newly cut leg.
- Use a damp paper towel to remove any debris near the lens.
- Hold the lens and tip the rear down while you remove the tape so that any debris will fall away from the lens.
- Pop your Contax G 28mm / 21mm on the Metabones mount following the appropriate instructions to line up and lock the mount.
- Use an additional m4/3 lens cap to protect your lens. The rear caps do not come with the Metabones Adapter.
- Place the Metabones and Contax G lens on your camera and start shooting away!

Here are a few sample pictures using the Contax G 21mm. Overall edge to edge sharpness is very good. A little vignetting and softness at the edges but very sharp and usable. I think it holds up very well. Probably my sharpest wide I have in a prime.
I took just a few quick run of the mill Philly landscapes at f/8 with the Contax G 21mm lens and just for kicks I attached my Raynox HD-6600PR055 wide angle adapter and I was pretty shocked at how well it held up too. When I pixel peep, theres a difference obviously and you can see vignetting and softness but I was expecting far worse. Both versions very useable to me. Very exciting stuff!
Philly Skyline & Schuylkill River Contax G 21mm f/8 & Raynox HD-660PRO55 & GH1

Philly Skyline & Schuylkill River Contax G 21mm f/8 & GH1

Fairmount Water Works Contax G 21mm f/8 & Raynox HD-660PRO55 & GH1

Fairmount Water Works Contax G 21mm f/8 GH1

Here's a few indoor shots just after I did the Contax G 21mm surgery to test for edge to edge sharpness with the Metabones adapter.


