Two step-up rings, two very different jumps
Step-up rings let you mount a larger filter on a lens with a smaller filter thread. The Dorr 43-46mm and 40.5-67mm rings both do that, but they solve different problems. One makes a small, incremental jump; the other bridges a much wider gap. Understanding the numbers printed on each ring is the key to choosing correctly.
The naming convention is consistent across both: the first number is the lens thread diameter, and the second is the filter thread diameter. That means the 43-46mm ring adapts a 43mm lens thread to accept 46mm filters, while the 40.5-67mm ring adapts a 40.5mm lens thread to accept 67mm filters.
What the catalog confirms about each ring
- Step-Up 43 - 46mm Lens Ring: Dorr Step-up 43-46mm Lens Ring: the first number corresponds to the thread diameter of the lens, the second number to the thread diameter of the filter. This is the smaller jump: a 43mm lens thread accepts 46mm filters. It suits lenses that are only slightly narrower than your existing filter set.
Step-Up 43 - 46mm Lens Ring - Step-Up 40.5 - 67mm Lens Ring: Dorr Step-up 40.5-67mm Lens Ring: allows a filter thread size of 67mm to be fitted onto a lens with a thread size of 40.5mm. This is a large jump: a 40.5mm lens thread accepts 67mm filters. It suits compact lenses that need to share a much larger filter system.
Step-Up 40.5 - 67mm Lens Ring
43-46mm vs 40.5-67mm: the practical differences
The main decision is how much of a size jump you need and whether the larger filter makes sense on the front of your lens.
- Size jump: The 43-46mm ring adds a small step from a 43mm lens thread to a 46mm filter thread. The 40.5-67mm ring adds a much larger step from a 40.5mm lens thread to a 67mm filter thread.
- Filter sharing: The 43-46mm ring is useful if you already own 46mm filters or plan to standardize on that size. The 40.5-67mm ring is useful if you want to use 67mm filters on a 40.5mm lens, for example to share filters with a larger lens.
- Handling and balance: A larger filter on a small lens can change the balance and may be more noticeable. The catalog does not provide weight or diameter figures for either ring, so check the physical size before committing to a large jump.
- Stacking and hoods: The supplied information does not confirm whether either ring can be stacked with other adapters or used with a lens hood. Treat those as open questions and test carefully if you need them.
How to measure your lens filter thread
Before choosing between these two rings, confirm the filter thread diameter of your lens. The number is usually printed on the front of the lens barrel or inside the lens cap, often preceded by a diameter symbol.
- Check the lens barrel: Look for a number followed by mm near the front rim, such as 43mm or 40.5mm. That is the thread size the ring must match.
- Check the lens cap: Many lens caps repeat the filter thread size on the back. If the cap fits the lens, its marked size is a reliable cross-check.
- Match the first number: The first number of the step-up ring must equal your lens thread. A 43-46mm ring fits a 43mm lens thread; a 40.5-67mm ring fits a 40.5mm lens thread.
- Match the second number to your filters: The second number is the filter thread you will be able to mount. Choose a ring whose second number matches the filters you own or intend to buy.
Step-up vs step-down: which direction are you going?
A step-up ring adapts a smaller lens thread to a larger filter thread. Both rings here are step-up rings: 43mm to 46mm and 40.5mm to 67mm. A step-down ring does the opposite, adapting a larger lens thread to a smaller filter, which can introduce vignetting on wide lenses.
If your lens thread is larger than your filter, you need a step-down ring, not either of these. If your lens thread is smaller than your filter, a step-up ring is the correct choice. Confirm the direction before ordering, because the first number always refers to the lens, not the filter.
Which ring fits your kit?
Choose the Dorr 43-46mm step-up ring if your lens has a 43mm filter thread and you want to use 46mm filters. It is the more modest adapter and keeps the filter closer to the lens size.
Choose the Dorr 40.5-67mm step-up ring if your lens has a 40.5mm filter thread and you want to use 67mm filters. This is a large jump, so consider whether the larger filter will suit the lens in practice, especially on a compact body.
If your lens thread is neither 43mm nor 40.5mm, neither ring will fit directly. Measure carefully and look for a step-up ring whose first number matches your lens.
What the supplied information does not confirm
The catalog does not provide dimensions, weight, material, or whether either ring supports stacking with additional adapters. It also does not confirm compatibility with specific lens models or filter brands. Use the thread sizes as your guide and check the physical product if these details matter to you.
