Craft laser-sharp images with your DSLR camera by crafting this homemade microfocuser for your lens.
Up your astrophotography game with this homemade microfocuser for DSLR lenses! If you're into deep-sky imaging and don't want your stars looking like blurry blobs, this DIY project's for you.
This bad boy is a lifesaver since most autofocus systems aren't reliable for astrophotography due to limited light. With just the right focus, you'll capture pin-sharp stars!
The microfocuser fits Canon lenses with outside diameters ranging from 67-95mm but should be suitable for other brands too. Check out our DSLR microfocuser template (PDF) for building help.
Why go micro?
DSLRs are a popular choice for deep-sky imaging thanks to their affordability and versatility. They're brilliant for various types of photography and the option to switch lenses based on focal lengths. Nevertheless, their autofocus systems ain't always reliable for astronomy since there's a lack of proper light. In such cases, precise manual focus is a must-have skill, and this DIY microfocuser's here to make it a breeze!
Building your star-focusing wonder
We've got two plywood rings in this design. One's clamped to a fixed part of the lens body using three nylon bolts, while the other attaches to the rotatable focus ring. There are 'lugs' on each ring that hold the adjustment mechanism. By turning the adjustment knob (make sure the focus is set to manual first!), the focus ring moves towards or away from the fixed ring, adjusting the focus. One full turn of the knob moves the ring 1mm, giving you tiny, precise adjustments for ultimate focus control.
Being a do-it-yourself project, there are some tricks to make it work smoothly. You'll need a drill, saws, files, a piece of 15mm plywood, M6 threaded rod, knob, nuts, washers, a short metal tube, a spring, nylon bolts, threaded inserts, epoxy glue, and sandpaper.
Ready to take up the challenge? Take a gander at the step-by-step guide. And don't forget to share your microfocuser masterpiece with us by sending an email to contactus@website!
Step 1: Design and cut the plywood rings
To start, mark out the design on the plywood using the template. Cut the inside of each ring using a coping saw or by chain drilling and filing.
Step 2: Finalize the plywood rings
Remove the template, then use a coping saw to cut the outside of each ring. Be careful around the lugs for the metal tubes. Before removing the template, mark the three insert positions on each outer circumference for the nylon bolts. Once done, sand everything smooth.
Step 3: Prepare the metal tubes
Carefully cut two lengths of metal tube - one short (15mm) and one long (35mm). Drill 6mm holes about 7.5mm from one end of each tube length. Gently wiggle the drill while running, making the holes slots. Remove any burrs with a file.
Step 4: Drill the plywood inserts
Make generous holes for the inserts. These would usually be tight, but to avoid splitting the plywood, make them at least 10.5mm diameter. Once completed, the plywood can be finished and smartened with a coat of paint or varnish.
Step 5: Install the threaded inserts and nylon bolts
Drill a slotted hole through the side of the lug to align with the hole in the short metal tube. Add the threaded inserts and nylon bolts to each ring before gluing. We used epoxy glue to stick the metal tubes and inserts into their holes.
Step 6: Assemble the adjustment mechanism
Screw in the nylon clamping bolts and assemble the adjustment mechanism. Give it one last check; you might need to do a little filing to align and move everything freely. Fit it to the camera lens, keeping the rings concentric and parallel.
- The precision and sharpness of your astrophotography photos can significantly improve with the use of this homemade microfocuser, especially for deep-sky imaging where the autofocus systems of DSLR cameras often struggle due to a lack of proper light.
- Building this DIY microfocuser for astrophotography not only enhances your deep-sky imaging but also provides an opportunity to delve into the technology involved, as it requires a variety of tools such as a drill, saws, and sandpaper.
