OGMA AP26-series cameras are often sold with a filter kit that includes a Zero Light Leak filter holder and a UV/IR 2'' filter.

Since these are full-spectrum cameras that only have an anti-reflections (AR) protective window in front of the sensor, you are required to use a some filter in order to achieve pinpoint stars. This is because different wavelengts of light will focus at a different distance. By using a filter, you are selecting a portion of the spectrum of light that focuses aproximatelly at the same distance.

If you don't use a filter, the stars will have a halo around them.

Depending on whether you own the monochrome or the color version of the OGMA AP26-series cameras, you will have to use a different strategy with your filters.

For the Color Astrophotography camera AP26CC

You should be ready to start imaging from day one by placing the addon OGMA UV/IR filter inside the OGMA filter holder. Attach one end of the filter holder to the front of the camera, and attach the other to your telescope. Done!

Depending on your optics and its required back focus distance, you may need to place some spacers between the filter holder and the telescope. If this is needed, you would have to adquire separately the spacers that match the diameter of your optics.

If you want to do narrowband imaging to reduce the influence of light pollution or moon light, you can purchase elsewhere a multiband pass narrowband filter or a light pollution filter that cuts down the type of light that's predominant near your location. 

For the Mono Astrophotography camera AP26MC

Some will suggest that you purchase an electronic filter wheel. If you have the budget for a filter wheel, you should buy one. If your budget is tight, keep reading because OGMA is on a mission to save you money. 

While an electronic filter wheel provides great convenience; it really isn't a requirement for a mono camera as long as you don't mind swapping the filters manually. In fact, owners of RASA telescopes, can't use filter wheels at all.

As mentioned above, OGMA AP26-series cameras are often sold with a filter kit. The OGMA filter holder from this kit can hold any standard 2'' filters. The UV/IR 2'' filter from this kit is a great luminance filter for monochrome astrophotography.

To start doing color narrowband with a monochrome OGMA camera, only two additional filters are needed: one for Hydrogen Alpha (H-Alpha) and one for Oxygen (OIII). Some reasonably priced 7nm H-Alpha and OIII narrowband 2'' can be found at Amazon.

Once your budget grows, you can gradually add the following items to your toolbox:

  1. Sulfur (SII) filter
  2. RGB filters
  3. Electronic filter wheel (to swap filters automatically)