590nm versus 720nm conversion

[Welrod50]

All,

I tried to search for this and drew a blank, so hopefully someone here can shed a little light on my question please in this new thread

I have today been in touch with a company about astro conversions and had a very detailed discussion with the chap there about filter removal on my Pentax DSLR and converting it for astro photo use. Jolly helpful, but he was asking me what results I wanted and what I expected to achieve. Now, as I can only go off my own unmodded experience so far, I plumped for a 590nm conversion as opposed to a more expensive 720 nm conversion. Might I please ask, what would be the benefit to me if I plumped for the 720 ? He did say that a 590 nanometre conversion would capture some visible light, but would be a particular benefit to red right through to infra red, including the Ha zone. We also discussed quartz conversion, but the different focal points for the light wavelengths put me off.

Has anyone any experience of what I can expect and would it be worthwhile going for the more expensive conversion. I ask as I'm pretty sure I will see an improvement over my current unmodded camera, but to what extent between conversions??

Cheers all

Scott.

[Photosbykev]

720nm is at the start of near infrared and very little visible red will get through. I've ordered an IR conversion on a DSLR and went for the 665nm filter on the sensor which will let some of the visible red through, the 590nm filter will let plenty of visible light through including the Ha band

This will be your filter

and a typical daylight shot at 590nm would be

the 665nm filter gives this result

and the 720nm looks like

[Welrod50]

Thanks very much for that Kev. It seems like I will be making a good overall choice then, as I had hoped I might use it for daylight IR photography sometimes too. Cheers for that input!!

[melsky]

Kev is right 720nm is the start of the infrared, I'm on my third generation of infrared camera for daytime photography a Panasonic G1 (good electronic viewfinder) I have tried it for astro use but it's only really to be proved useful for lunar and planetary imaging in blue skies.

Mel