Lightwave 0.6 reducer

[Thalestris24]

Anyone had any (imaging) experience with the 0.6 reducer? Maybe with a 1" sensor (13.3mm x 8.8mm) or possibly (stretching it!) with an aps-c?

Thanks

Louise

[michael.h.f.wilkinson]

I personally am looking at this 0.6x reducer:

https://www.teleskop-express.de/shop/product_info.php/info/p7943_Long-Perng-2--0-6x-Reducer-and-Corrector-for-APO-Refractor-Telescopes.html

which should work for APS-C sensors according to the TS site.  That fits with the 26.8 mm diagonal of the APS-C sensor format, compared to 48mm * 0.6 = 28.8 mm image circle of the reducer. My SCT 0.63 reducer also shows little or no vignetting on my APS-C sensor cameras

[Thalestris24]

5 minutes ago, michael.h.f.wilkinson said:

I personally am looking at this 0.6x reducer:

https://www.teleskop-express.de/shop/product_info.php/info/p7943_Long-Perng-2--0-6x-Reducer-and-Corrector-for-APO-Refractor-Telescopes.html

which should work for APS-C sensors according to the TS site.  That fits with the 26.8 mm diagonal of the APS-C sensor format, compared to 48mm * 0.6 = 28.8 mm image circle of the reducer. My SCT 0.63 reducer also shows little or no vignetting on my APS-C sensor cameras

Yeah, I was looking at that but a) the exchange rate is pants and b) it looks identical to the Lightwave x0.6 one. The latter also says it's ok for f6 and greater scopes - but... The scope I'm thinking of using it with is an 80mm/f6. There is also the x0.8 version which is likely to give a flatter field. I've read about people having to adjust the x0.6 spacing to within < 1mm.... plus tales of vignetting. Hmm...

Louise

[michael.h.f.wilkinson]

19 minutes ago, Thalestris24 said:

Yeah, I was looking at that but a) the exchange rate is pants and b) it looks identical to the Lightwave x0.6 one. The latter also says it's ok for f6 and greater scopes - but... The scope I'm thinking of using it with is an 80mm/f6. There is also the x0.8 version which is likely to give a flatter field. I've read about people having to adjust the x0.6 spacing to within < 1mm.... plus tales of vignetting. Hmm...

Louise

I am also thinking of using it on an 80 mm F/6. Would be nice to try before I buy.

[michael.h.f.wilkinson]

BTW, I use a Tele-Vue TRF-2008 0.8x reducer with the APM 80mm F/6, and that produces good results (or at least, i like them).

Not perhaps perfect in the corners, but pretty good for a first go, without trying out any alternative spacing

[Thalestris24]

1 hour ago, michael.h.f.wilkinson said:

BTW, I use a Tele-Vue TRF-2008 0.8x reducer with the APM 80mm F/6, and that produces good results (or at least, i like them).

Not perhaps perfect in the corners, but pretty good for a first go, without trying out any alternative spacing

A lot depends on the size of your sensor, obv. If I don't get any positive responses re the x0.6 I'll play it safe with the 0.8

Louise

[michael.h.f.wilkinson]

1 hour ago, Thalestris24 said:

A lot depends on the size of your sensor, obv. If I don't get any positive responses re the x0.6 I'll play it safe with the 0.8

Louise

The above was shot with a Canon EOS 550D (modded), so APS-C sensor

[Thalestris24]

5 minutes ago, michael.h.f.wilkinson said:

The above was shot with a Canon EOS 550D (modded), so APS-C sensor

Yeah, you should be fine with that at x0.8. I have a x0.79 on my f7 and it's been ok previously with a dslr, now a Atik383l+   

Louise

[Thalestris24]

Hmm… I'm wondering about the 0.8x tsred80 now (from 365Astro) which is a bit more expensive than the Lightwave 0.8x but significantly cheaper than the Photoline TSRed279 which is likely a better match for a triplet APO and is the one I have on the 115mm/f6.96. They do say the tsred80 can work ok with f6 scopes but there's probably only one way to find out!

Louise

[Thalestris24]

Hmm... I'm having doubts about fitting a focal reducer at all now. The only thing it would seem to do is increase the fov. An 80mm scope is still an 80mm scope. They are essentially designed to illuminate the area of at least an aps-c sized sensor. Putting on a camera with a small sensor means I'm throwing away a lot of photons but there's an advantage in having a more sensitive sensor. Adding in a focal reducer won't help to shorten exposures? I'd probably lose resolution? What I'd really like to do is reduce the size of the light cone to more closely match the sensor size. Does anyone know a way of doing that? Maybe I'm overthinking things? I've got a headache ha ha.

Louise

[Thalestris24]

Just a quick update - I got a Lightwave 0.8x reducer and have fitted it to my 80mm F6.  Now F4.8 . I've not been able to try it out properly but had a quick go between clouds earlier. Seems to be ok - couldn't see any distortions, though only using a small sensor anyway. Hopefully I'll be able to give it a proper test before too long - fingers crossed!

Louise