So why did I recently purchase a 336mm f4.5 refractor over a 300mm f4.0 camera lens?
Here's a few positives...
- flat field (with flattener) no coma
- built in 10:1 focuser
- came with sturdy dovetail mount, rings & riser blocks.
- no 6 leaf iris star spikes
- handbuilt & tested before shipping
- purpose Built for AP
- fixed aperture
Others may have different opinions, but these made my decision easy.
Hope that's useful
Cheers
Andy