picclock

Hi wulfrun I could just do that, but this is my portable setup and I'm trying to keep the weight complexity and size down to a minimum. Good point about the bulb setting, because as soon as you put a time on it it ceases to be bulb .. . I hope the skies have been kinder to you over the last few weeks as its been permanently cloudy (and wet) down here in Dorset. So hacking the firmware magic lantern style would be ideal, but alas the magic lantern crew have not caught up with the EOS RP yet. I may make a custom intervalometer and fit it in the battery box. I've heard you can get a pair of cheap headphones with a 2.5mm plug and just use the lead from them, so I might put that on my round tuit list. Best Regards picclock

Hi Alan My RP does indeed have an interval timer, however it does not seem to play with Bulb mode. Manual mode is only up to 30 second interval so a bit limited. When enabled it can take up to 99 shots, or, as I have just found out, an unlimited number if set to zero. By setting the interval at 30 secs. an exposure time of 28 secs is possible, allowing ~2 secs to save the image. Using an unlimited number is OK, so I think I will have to make do with up to 28 sec exposures. (Someone clever needs to hack the firmware .. ) Best Regards picclock

EOS RP How can I take sequences of longish exposures using bulb or manual mode?. Manual mode goes up to 30 secs, which is OK, but I would like to take sequences of say 1-500 exposures at 10-30 secs or similar. I can't seem to find a way to do this, although the camera has the ability, but not in the right modes, B or Manual. It is possible to do so wirelessly. I have the canon connect app but its not that good. Other apps claim to work but I'm not keen on using a phone, which turns itself off after a short time, or may be interrupted by calls or texts. So my last resort is to knock up / buy an intervalometer ??, basically a timer which will connect the contacts on the external bulb jack on the camera. I have a dummy battery pack which would likely have room inside it for such a thing. Any thoughts or ideas much appreciated. Best Regards picclock

I've just got a 6" sct and would like to use it with my EOS RP. But the sensor size in the RP is 35.9 x 24 mm which means that only around half of the sensor area is useable. I'd rfeally like a lens in an adapter, like an eyepiece for camera, that I can fit to the camera to get the use of the full frame. Do such things exist or are there alternative methods I could use. Any assistance much appreciated. Best Regards picclock

High Dean I'm far from an expert on this, but it might be possible to insert an off axis guider before the camera and use an eyepiece with that. Best Regards picclock

Hi I have an ioptron rc8 optical tube which I want to mate with a camera. ATM to get correct focus with an eyepiece I have to use 4" of extension tubes. Does anyone know if this distance is likely to change with a canon dslr camera? I am very concerned about the weight overhang on the back of the telescope. Any advice much appreciated. Best regards picclock

I've ordered one of these on the assumption it would do as in the adverts - balance a load up to 12kgs. However reading the manual it says the purchase of an extension bar is needed for loads more than 6kgs. If I can know the length of the original shaft, I can make a bar to the correct full length prior to the mount arriving, or at least get the 20mm stock. So if anyone has one of these a quick measure up would be very much appreciated 🥳. Best Regards picclock

I'm going in a similar direction using the CEM25 using an off axis guider, a small prism which splits off part of the primary optical path, hence no finder scope. FWIW my all up weight is ~8.5kgs. Good luck Best Regards picclock

@shimrod >> your current scope! Currently I have no scope 😪. A couple of decades ago I had an 8" sct, a meade lx10. This got written off by accident by one of my kids, resulting in the mirror and corrector plate being broken, beyond redemption. So kids, no time, no finance meant I had to give up the hobby. Now am retired and have a little cash, and time. >>You seem to have deviated from your original goal of a smaller and more portable version Smaller and more portable. Well it will be a lot lighter than the LX10., 13.1kgs vs 22.2kgs. So maybe more portable, smaller not so much. Will likely fix a carrying handle to the tube. Its difficult for me to downsize when I remember the really good seeing I had with my old one. >> The only reason I can see for getting the RP would be if you also wanted to use the camera for 'normal' photography as well - it's not like you're saving money over the purchase of a dedicated Astro camera. Having a 'normal' camera gives massive versatility. When 'she who must be obeyed' sees it, it will be recognised as a family asset, and I can even take pictures with it (of her of course). If I show her a small red cylinder and tell her I bought it for £900 there will be much weeping and gnashing of teeth, likely from me. It will be interesting to see how it stacks up against a ZWO ASI294MC-PRO, because after you subtract the dark frames I suspect there is not a lot in it. For a camera to have a QE of 68% is quite simply amazing. Should be a fun toy. @vlaiv Your quite correct about the off axis guider. That one you linked to seems really short. I think that must be the way to go. Many thanks for your comments and assistance. Best Regards picclock

@vlaiv I think the CEM 40 is beyond my budget ATM. I like the idea of an OAG, but I dont like the extra added length or the partial obstruction to the light path, so I think I'll use a conventional finderscope type guider if I need it. Just a couple of questions. If you have this scope what are the cool down times like?. The rp camera is very lightweight for a canon DSLR, @485g inc battery. How sensitive is the OTA to weight hung of the back, and does it affect the focus much. Best Regards picclock

@Main Sequence Thanks for that information. I have looked into this a bit more and have revised my list of purchases in view of your comments and further research. The mount is really important. I found with my old wedge alt azimuth LX10, that I could use the cooldown time to get the tracking sorted, and once done it was pretty good, just a case of getting the habit. I think I will be going for iOptron CEM25P. It has reasonable load carrying and is allegedy pretty accurate. Nice low power requirements. Most importantly its affordable. Re the OTA, Ive been looking at an iOptron Photon RC8 8" F8 Ritchey-Chretien. This seems a pretty good buy and with lots of aperture for the deep space objects. Only snag with this is it does not come with eyepieces, finder scope etc, which is a bit tacky (wish I'd kept my old Meade ones 🥴). Plus points are active fan cooldown, no dewshield needed, no coma, spherical or chromatic aberration (so it says), although its not a flat field. Re the sensor, Ive looked into it and think the Canon RP will be pretty close in performance to the ZWO ASI294MC-PRO and likely better than the uncooled ASI294MC. It has a larger sensor (35.9 x 24 mm vs 9x13mm) and larger pixel size (5.73um vs 4.63um). Without active cooling its power requirements will be minimal. It may be a bit noisier but should still give pretty good results., especially after a few reference frames. With a bit of luck and using zero drift alignment the exposure times will be relatively short, <5mins, so hopefully no guiding needed. I'm just about ready to go with these so if anyone can see anything wildly out of line I'd value your comments. Best Regards picclock

De ionised water at Tesco ~£2 for 2.5 Litres from memory. Sold for steam irons etc. Best Regards picclock

I was wondering if there is any performance difference between a normal equatorial mount and an alt azimuth one with a wedge (apart from not having to lug weights around 🤪). I remember having pretty good tracking with my old meade lx10, but that was ~20 years ago. Re the cmos camera. I've been looking into the Canon Eos Rp (35.9 x 24 mm CMOS sensor , 26.2Mp ) rather than go for the dedicated Astro cam. Conveniently this already has a filter to allow hydrogen reds through, so no modification necessary, leaving it available for normal use. My info (may be suspect) says 68% QE for the canon Rp. Does anyone have both for a comparison ? Any help or suggestions much appreciated Best Regards picclock

Jack of all trades ??, master of none - but perhaps good enough. I am returning to the hobby after a number of years and am looking to put together some kit for observing and occasional photography. My old telescope was a Meade 8" LX10 sct. I want to keep the size and number of parts down to a manageable level. The idea is to put together a new "goto" kit but a bit smaller and more portable than the 8". I'm thinking a Meade 6" LX65 sct. Not sure its worth it for the ACF version. Quite like the idea of being able to mount another scope next to the primary one. I'm wondering if I could get reasonable pictures using one of the sensitive ZWO cooled pro one shot cmos cameras. Because the exposure times are quite short I am hoping that I will be able to achieve good results despite the lx65 being an alt azimuth mount.. Any thoughts or comments on this odd marriage much appreciated. Best Regards picclock