Lumicon DSF or IDAS LPS

[DonB]

I'm assembling my AP kit and trying to decide which light pollution filter to get for DSOs.

I'll be using an ED80t CF with an unmodded Sony A6000. The main source of light pollution where I live is the cool bluish streetlights. I'm in a small suburb with no large populations in the area.

Depending on who you read, both the Lumicon and IDAS are the best.

Would one be preferable for my situation?

If the IDAS, which one between the LPS-D1 and LPS-P2? Here too I've read conflicting opinions on which is more suitable for an unmodded DSLR.

Thanks,

Don

[cometcatcher]

I would suggest if you live in a small suburb to just shoot through it without a filter. Given your light pollution is mild, you would likely lose more light though the filter than any blocked LP. If you are shooting galaxies or star clusters, don't use one.

The exception is nebula. An LP filter can boost the contrast of Ha nebula even if you have no LP. The Lumicon deep sky would have the strongest effect, but also requires adding more exposure to make up for light losses. In a DSLR this can be problematic. Being uncooled, longer exposures introduce noise. In that respect, the IDAS filters which are more of a gentle filter may be more suitable, especially in summer. The IDAS filters are easier to work with though in general due to better colour balance and blocking less light.

The other thing that comes up is colour balance with filters. Any filter will shift the ratio of Ha to OIII in nebula the camera records. You will find with an unmodified camera and no filter, blues from OIII come through strongly but red Ha is weak. With a filter, red Ha becomes stronger. The stronger the filter the more dominant the red Ha will be, so the Lumicon would show reds more strongly.

There is no right or wrong filter here. All have their place depending on the effect you are trying to achieve.

[DonB]

Thanks Kevin for the reply, that's very helpful information. Even though I've read a lot on the web about these filters I wasn't aware of the relative strength of the filters and the tradeoffs that arise from that.

:thanx: