8472

4 minutes ago, cmanley134 said:

Great, thanks! Any special tools needed, or just hacksaw and sand down any rough edges?

Not really, a hacksaw should do it and yes, you don't want to leave any burrs to lacerate your or any future owner's hands.

Upon re-assembly, I covered any exposed metal with black self adhesive flocking material.

Just be wary of how much of the drawtube you remove.

Take too much off and the tube will come off the rollers in the focuser when you wind it fully out.

Additionally, I shifted the primary up the OTA, so I wouldn't have to saw too much of the drawtube off.

Good luck!

No, you can completely remove the drawtube from the focuser, from your picture.

I'd go with RVO over DFO any day of the week.

16 hours ago, braybarr said:

Does anyone have experience dew heating their coma corrector? I live in a very humid area where my CC has been getting dewed over recently. What can I do?

Mount the OTA with the focuser at the 12 o'clock position.

Although I don't use one, a dew shield may also help. I've also made a secondary dew heater.

Yes, it should be fine with your intended setup.

Fantastic shot.

36 minutes ago, AL1 said:

I think it is surface area that gives light gathering power

i.e

(pi X (130/2)^2) - (pi X (47/2)^2)  =  (pi X R^2)

 

R = sqrt((130^2-47^2)/4)

R = 60.6 mm radius for equivalent refractor

Just over 120mm diameter.   I would double check my maths though

 

God, I'm stupid - of course it is! 🤦

Thanks!

Long time 130P-DS owner here who's performed a few mods (part flocked, primary mirror moved up the tube, shortened drawtube for zero light path intrusion, etc etc).

I'm not sure if this has been brought up before, but am I right in thinking the light gathering surface area of the primary mirror is roughly equivalent to an 80mm refractor (considering the central obstruction of the secondary is 47mm)?

(130mm X pi) - (47 X pi) = 260.75mm²

260.75 / pi = 83mm

Happy to be corrected and sorry if this has already been beaten to death and/or debunked.

Here's a newCepheus image of mine with my Samyang, QHY mono and HOO filter set.

Just over 15.5h, lens wide open

Of the 3, I'd go with the 294.

On 19/11/2022 at 17:10, scotty38 said:

Adapter I used:

https://www.modernastronomy.com/shop/accessories/adapters/qhy-small-screw-adapter-020063/

 

You may want this kit anyway and it includes the above adapter:

https://www.modernastronomy.com/shop/accessories/qhy-accessories/qhy-m42-all-in-one-adapter-kit/

Wonderful, thanks for those links.

52 minutes ago, scotty38 said:

I have a 294 and originally the S-US and it will connect with the supplied "dovetail" connector or whatever it is called. I did buy an additional adapter that will allow a bolted connection but then I think you will need other adapters possibly. I say possibly as I changed my mind, went 36mm and bought the medium wheel anyway 🙂

Thanks for that.

I'd like to fit an EF adapter on the camera side of the FW, so If I'm not mistaken, i don't think there'd be enough back spacing distance to retain the standard circular dovetail. Also that thing looks prone to tilt issues to my eyes

A quick look online at the bolt spacing of the FW and the camera minus dovetail seem to tell me they differ somewhat? 

Happy to be corrected.

Has anybody with a QHY163M or QHY294M successfully paired it with the above filter wheel? What accessories are need?

I know the medium fw is recommended, but I have 31mm filters. Asking here as neither UK or Hong Kong based retailers can be bothered to reply to my inquiries.

Cheers

Anyone have any recommendations as to what to cover the shiny silver drawtube with, as to potentially reduce internal reflections?

I haven't flocked any if my OTA, nor have I shortened the draw tube in any way.

Thanks.

My pick would be either the 533 or 294.

I've owned a Z61 for years and can tell you the 61mm aperture can no way resolve 1.37 arcseconds. Dawes limit is about 1.9, so the small pixels of the 183 are wasted.

I also have a 294m, and it's a great match binned 2x2 (2.65 arcseconds/pixel). Unlocked it is way oversampled (similar pixel pitch as 183).

23 minutes ago, newbie alert said:

Beltingonline can supply many different versions of pulleys and adapt the bore size and even reduce the face width if space is the issue..

Pe comes from the worm

Thanks for that.👍

I'm aware of the PE in the worm. Just thought maybe elimination of spur gear backlash may help, or is it an exercise in futility?

Yes, I've just been told the intermediate gear can be ignored, so I've calculated the setup to be 1:1.54167.

As said, the interesting bit will be finding a set that will fit...

Cheers all

Hi,

To reduce the PE of my tracker, I'm toying with the crazy idea of replacing the three spur gears with a belt driven system.

There's no off-the-peg commercially available solutions, so I'm weighing up doing it myself.

I've stripped down an tuned mounts, including the SA previously, but never undertaken a belt conversion.

So, my question is, the gear arrangement is a 24T drive gear going to a 42T intermediate spur gear, to a final 37T spur gear connected to the worm. What two size belt and pulleys would I need to replicate the gear reduction ratio?

Thanks,

Kev

If it hasn't already been mentioned due to the sensor position in each camera, it is possible to use smaller filters in the ZWO.

The QHY's sits deeper in the camera, hence potentially requiring larger filters.

First light with my Samyang, and I opted for a quick and dirty evaluation with just my Star Adventurer and modified mirrorless camera.

Sadr Region in HOORGB, using my l-enhance for bicolour and RGB stars combined. F/2 for both sessions.

I now have a unique-to-me "problem" where wide open, the lens is so fast that I am spending more time dithering between subs than imaging, even at base ISO!

It's clear this lens hoovers up photons way faster than any of my previous astro optics.

Can't wait to get some proper imaging done with my mono setup. 

Hi all,

I took delivery of my EF mount Samyang a few weeks ago, but with the curse of new gear, haven't taken any astro images yet.

That said, it seems great so far for daylight use and will hopefully come to replace my venerable 135mm F/3.5 and 200mm F/4 SMC Takumar lenses.

Although I already own a W.O. Z61 mount (which came with a free telescope lol) which fits this lens perfectly, I didn't want to share it between my Z61 and the Samyang, so I bought the Sigma 70-200 mount recommended previously on Amazon for £15.

As previously discussed, it is maybe a mil or two too big, but fits perfectly with the application of some foam tape I have lying around, applied around the inside of the clamp.

Hoping to put it to good use in some Bortle 3 skies down south next month!

Splitter has arrived and I'm pleased to say, it works perfectly. Both cameras activate their shutters simultaneously, as planned.

Now I just need clear skies...

Thanks all, some very useful information to digest.

I've just bought a splitter, so I'll see how it works out, when it arrives.

Judging by the useful link posted, I won't bother with the diodes as I am only firing two cameras.

Cheers

Hi,

As a mk1 Star Adventurer owner, I have happily been imaging with my M4/3 body for a good while using the SA shutter release port.

As I have 2 similar cameras and lenses, is there a way I can trigger two cameras from the shutter port?

I was thinking something like this.

https://www.ebay.co.uk/itm/2-5mm-Stereo-Audio-Jack-Splitter-Y-Adapter-Cable-Lead-Plug-to-2-Socket-Gold-20cm-/383003119126?_trksid=p2349624.m46890.l49286

Obviously, blowing either my tracker or cameras up is not high on my wish list, so any reason why it would not work?

Cheers

4 hours ago, Alien 13 said:

 

I would be interested too, dont have the Sammy at the moment but my Son has one which I might be able to borrow.

I know the Canon teleconverters push into the lens so cant be used with the EF/S range for example but have a feeling that my Kenko MC7 (X2 TC) might work with the Sammy as I can even uses it with most EF/S lenses like my Sigma and Nifty 50 as well as the full frame Canon 70-200 as detailed in my signature..

Alan

As Alan mentioned, it looks like the Kenko and maybe Sigma converters may physically fit.

I'd love to know if your son's lens works, if you do ever get to test, Alan!