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I know im resurrecting an almost decade long post, but I'm about to get a D40 and cannot find the source for this very important statement. I'm sure Rawhead is correct, but can anyone confirm this or provide the source, or is this simply a personal observation? TIA Minos

Wonderful pictures, truly! I'm thinking of buying this camera and I was hoping someone could help with regards to where in the spectrum the IR glass in front of the sensor cuts off. Basically, is it above Ha (656nm); which judging from another awesome Ha picture you posted with this camera and the fact that it's an astronomical camera, it is. I have searched the internet high and low for this value and cannot find any info and would very much like to confirm this. Many thanks and clear skies to you all 😊 P.S. does it also cut UV? EDIT: my apologies, I confused the model number of the camera, I'm referring to the QHY163C.. EDIT2: FWIW, I found out from QHY that the IR cutoff for the QHY163C is 680nm and you can order it with an AR glass aswell...

Another small step towards maximising the 130pds! Thanks for sharing 🍻 Do you find you gain backfocus with the Lacerta rather than the stock clamp?

Indeed..I often get carried away by the details, but it's too much fun and I learn a lot, like the fact that I don't want to spend time erasing bad data from bright stars in PI. I'd rather go down to the nitty gritty road and effectively plan the time I invest with my imaging equipment to get the best data possible. I mean, what if I wish to keep the stars & detail et al., in the reflection that your editing out? I'd need as precise a configuration as possible, as ive learned with my refractor and to do that sometimes i need to get carried away with how many mm's are left in an M48 thread. Nevertheless, thank you all so far, sincerely, I have learned so much and I'm enjoying it in good spirits too 😊 can't wait for my 130pds 🚀🍻

The only reason i mentioned the custom adapter, is that it would have more M48 thread available in comparison to the FUFMPCC, which eats up about 2mm

One could order a custom M54x1mm male to M50x0.75mm female adapter and thread it to the synta drawtube, leaving the GPU CC's M48 thread fully exposed..

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p5836_GPU-Aplanatic-Koma-Korrector-4-element-fuer-Newton-Teleskope-ab-f-4.html In the technical specifications for this product, it specifies an M50 connection behind the M48 thread, see it in the picture. The SW seems to have a ring in place on the M50 thread, so I presume it unscrews.. EDIT: i meant this product, which is essentially the same as the above without the ring. http://www.teleskop-express.de/shop/product_info.php/info/p6706_TS-Optics-GPU-superflat-2--Coma-Correktor-for-Newtonian-telescopes--4-element.html

You are correct, in that you wouldn't be able to rotate the camera and live with it's final position, which I do with my short refractor as I prefer the threaded connection to clamping but with rotation ability.

The ring on the SW equivalent of the GPU CC is an M50 thread and should screw off.

There seems to be many M54x1mm male to T2 adapters on sale, but I have only found the Lacerta adapter provides an M54x1mm to M48x0.75mm female thread, but that adapter sounds like it has issues with its rotating functionality. Baader makes these adapters but the M54 side has a 0.75mm pitch (for filters) not the 1mm needed for the Synta drawtube. Perhaps the FLO bespoke adapter service is still in effect and people can order a straight-up M54x1mm male to M48x0.75mm female adapter (with no rotation functionality like the Lacerta adapter) for using M48 threaded CC's on synta focusers, like the one on the 130PDS. There should be enough market for this i presume, considering synta scopes are so widespread in the imaging world, and of which many imagers use M48 threaded CC's.

Thanks Rich for taking the time to reply. Vignetting with T2 did cross my mind when I was thinking of this adapter in use with the MPCC, as that's the connecting thread it uses. However, i'll be using the adapter with the GPU aplanatic CC, which has the wider M48 and would therefore avoid possible vignetting on APS-C sensor. This gave me hope that perhaps this Lacerta adapter is actually better suited for the GPU CC rather than it's advertised use with the MPCC. My concern is whether or not this adapter combination will give a secure enough connection to the DSLR flange ring, being that a 4mm long M48 male thread on the coma corrector hides approximately 2mm's inside the adapter. I think 2mm left over is sufficient to lock into the DSLR flange ring, but I don't think it will hold a lot of weight. Nevertheless, as soon as it arrives, i'll be using my 130PDS with DSLR + CC only, so not too much weight. Thanks again

How so?

Hi AdamJ, FWIW, when I image with my unmodded 450D on my short refractor, i use a CC <70mm> CMOS spacing for good correction, but with my full spectrum 1200D, I use a CC <65.3mm> CMOS spacing. I believe the reason for this reduction, is as you've described it, in that all glass filters inside the full spectrum camera are removed, which reduces the effective focal length required. Therefore, if you minimise your spacing as you say, would probably work better. Try it and see On a different note, a threaded connection to the focuser is assuredly always more likely to be optically aligned with the collimation than a clamped connection, with less flexure and more stability. I wonder if many of the aforementioned chromatic aberrations and bloating reported in certain CC's where also in part, due to being clamped in the focuser rather than threaded.. I understand that the drawtubes in Synta focusers found on the common newtonians utilise an M54x1mm female thread that usually houses the removable 2" clamp. Furthermore, all previously discussed CC's such as the SW 0.9x, MPCC, GPU aplanatic etc.. utilise a male M48x0.75mm to connect with a DSLR. Therefore, one would require an M54x1mm Male to M48x0.75mm female adapter, and they could adapt the Drawtube + CC + Spacer + DSLR combo in a threaded fashion. Uranium has successfully demonstrate this concept after loads of DIY with the SW0.9X CC. Such an adapter would not only ensure an improved connection, but also would provide a little more backfocus, allowing the drawtube to be racked out further, thereby minimising the intrusion that causes D-shapes on bright stars and negating the need to trim it down. Fortunately for us, the Hungarians at Lacerta make such an adapter (I've ordered one!) and there is also a T2 version (though it looks less secure). Food for thought.. EDIT: I saw on another thread here that the good folk at FLO used to do a bespoke adapter service. Maybe that's still on?

Hi Stamatis, Thank you so much for this information, it is very helpful! The TS website for this filter states 2.2mm under the specs. I will get in touch with them and confirm this as I bought it from them. I wonder if the 2.2mm is not for the glass thickness, but some other measurement. Thanks again😊👍

Ah, thank you for the correction. That translates to 54.3mm, which is 1.8mm more than the 52.5mm recommended. This changes things a little as now i need to get one of those thin EOS locking rings (thanks alacant) and build up the distance with spacers. Thank you again for pointing this out 😊