>>4343237>>4343254Greater focal lengths get you more distance from the subject which is mostly important for living subjects. However this assumes the minimum focusing distance is the same (say, 0.5m) which is measured from the sensor not the end of the lens. When using extension tubes the general rule is wider lenses are more effective than telephotos, and to keep the extension length to half or less than the focal length of the lens you're using, but going slightly over won't matter much. What you're mostly concerned with is your magnification level and working distance. Working distance is the length measured from the end of your lens to the subject at closest focus.
As you add extension tube length three things happen.
- You reduce the MFD and thereby increase your magnification
- You add length to your lens thereby reducing your working distance (and can come into scenarios where the focusing point is behind your lens)
- You reduce the amount of light reaching your sensor
>When i just threw them all on it was cool but the object had to be basically touching the [lense]Use a smaller length of tubes, your MFD is too close
>Which [extension tube] would be better and what length extension?Focal distance is not super important but most actual macro lenses start at 100mm, so use your 85mm and slap on the highest length extension tubes you can that leaves you some working distance
>>4343164>Can I really just shoot everything at f.20+ if I hate computation photography?Yes, at such short focusing distances your DoF is razor thin and you'll get pretty much nothing in focus below f/8 and won't have much to look at until you're at f/13~+. Also depends on what size sensor you're using since smaller sensors (like M43) have a greater DoF for the same FoV. Diffraction (the thing we don't like when using narrow apertures) is not great, but neither is having nothing in focus.
Pic rel shot at f/9 with fuck all in focus.
