Magnum

I just added a bit more to my last reply while you were typing yours

Oh that's a good chart, yes the 2x does seem to have a negligible change doesn't it. OK, so I would go straight for trying the new Baader at 1.3x, but I would put the ADC and or filter wheel in front of the Baader 1.3x . if you keep the ADC in the middle like you have it now the spacing will be too much for the Baader and make it act at something like 2.5x. Though they do say that ADCs work better at higher FL, there is a point where the optical aberrations introduced by the ADC become more important than the gain from removing the dispersion, but as your scope is already f11 I would think its already above the point and shouldn't be an issue. You will need to have a play around with the order while previewing Jupiter to get the image size you want, a quick and rough way to check is to adjust your ROI box in the capture program if the planet just fits in the ROI then you know thats how big it is. You can set any custom sized ROI in sharpcap. I like Jupiter to be around 480 pixels at the moment now that its apparent size has shrunk a bit. Remember all the maths is fine and important, but doesn't hurt to test it with experiment 🙂 and I like to experiment by finding the best images in the world then replicating what they are doing. Mr Peach has been the best planetary imager in the world for almost 20 years he's working at 0.08"-0.1" so I find it very hard to argue with that. Saying that I think Marco Lorenzi has now surpassed Damian with his last few images since he upgraded to using a 21" dob on his balcony in Singapore, he's also working at 0.8"/pixel https://www.glitteringlights.com/Images/SolarSystem/Solarsystem/i-gJzz7J8/A Lee

Yes I think if you weren’t using an ADC then you could use the 2x powermate, but the adc will push it a bit too far so the Baader barlow will get you something in between. rember though that with barlows extending the spacing increases the magnification, but with power mates it’s the opposite, extending the spacing decreases the magnification. So you could theoretically back of the mag with your power mate by using a bit more spacing. do you have the ADC before the barlow or between the barlow and the camera? As that makes a big difference too. Lee

From UK 0.07” will be pushing it, but around 0.09 - 0.10” is doable

In Damian’s talks he classes anything below 0.06” pixel as oversampling, 0.08” - 0.10” as ideal sampling , and 0.14” as under-sampling. this is for scopes in the 30-40cm aperture range. im attaching screen shots from his talk. this is of course under perfect seeing In barbados, but I still find 0.1 works best for me. remember those calculators aren’t taking into account unsung lucky imaging with 10s of thousands of split second exposures.

Yes sorry I typed it wrong I will go back and correct it to avoid confusion in the thread

My jupiters measure around 500 pixels with my current sampling with the 12” scope, I’ve found that about the ideal. So about 0.1”/pixel, Damian and GO are a bit higher than that around 6-700 pixels or around 0.08-0.09”/pixel but that’s with 14” scope and perfect seeing.

Yes and to measure a simple way is to just crop the image in photoshop until it’s just touching the limbs the go to image size to see how many pixels it is. though first make sure it’s rotated so the equator is level and wack up the mid level slider to expose the limb darkening enough to see the true edge. alternatively win jupos can do image measurements precisely.

Chris told my personally that hes working at f24, this was a few weeks ago. Barlows never give the exact multiplication factor they claim and the adc spacing to the barlow will add a bit more, im sure hes measured jupiters disc in pixels to get a true value before telling me. as I do that with mine each time i change anything. i hope you like the baader barlow, at least it wasnt too expensive, i bought it after seeing an amazing saturn taken with one, Lee

Though can’t tell what size the rings are from the listing so would need to ask to see if they are larger than your Altair 80 tube diameter.

Yes I know its for visual, but you said earlier in the thread you were looking for a way to mount your Altair 80mm to the top for wider views, so I thought these guide rings would be the easiest option as they have the correct curvature for mounting to the front and rear cells and include rails with sliding rings so you can balance it. cheaper and more functional than buying another dovetail. Lee

My old 12" LX200 is still working fine on its original fork drive, but if it ever dies I will have to buy a 2nd EQ8 for it. you should do some planetary with the 14" once you have it mounted, the 12" is proving excellent for the task You can just see the Astro Engineering guide scope rings that I picked up as new old stock for from ENS for only £25. It's a good idea to vacuum out the screw holes after de forking before you put the bolts back to avoid swarf going inside. the tinniest smear of grease on the bolt threads helps if you are going to be removing them a few times.

Hi Olly, I have a set of these for my 12" LX200 but looks like he has sold out of 12" & 14" versions https://ensoptical.co.uk/index.php?route=product/product&path=126&product_id=13815 Though just found this rail and ring system on eBay which fit the 14" which include a cheap guide scope. If I had your scope I would snap these up fast 🙂 https://www.ebay.co.uk/itm/203925817273?hash=item2f7aed07b9:g:lvMAAOSwI9ViaByn&amdata=enc%3AAQAHAAAAsG%2FrUJ87uwu85svy6G%2FQ7RuVbCpcHjI0bg%2Bt1XxGIJriLvveM1KG3B7njz52%2Fbz0oURB5m9Cvn1mbdl2UL61Cam6yL9aDxG938i3SIO%2Fi%2Fuh2Eg7Ogb38hlNIZ6J272gpCrbQGMwk2cqxE4G0uPjRo%2Fx0osfTRUro3bKtOjC0vTrVv9Pi2UvTze0jmKOMTrEfPTyuT9wLJfj09N73MTUqCBsaJcJTYUd0Fc6j%2B7zDjza|tkp%3ABk9SR4St3NuHYQ Lee

Yes I do reduce my FL when using my 850nm IR filter and 889nm CH4 filter, though not by as much as that. I normally just take the spacer out of the Barlow. Oversampling doesn't bother me really but the 12" aperture isn't really enough to produce a bright enough image for using the CH4 at the same FL as with the other filters. Id seen a talk by Cristopher Go when he was using the CH4 filter with his 290 mono and he would bin 2x2. but once he got the 462C he stated that it was so much more sensitive in IR that he doesn't need to Bin with it, for ease of use he doesn't adjust his FL as that would mean re focussing and be more time consuming. So all of his images are taken at F24 with the C14 at 8.5m FL His CH4 images are still presented at a smaller scale, but I think thats because his 1.5x drizzle stacks his visible light captures but not the IR ones. Saying that though I may still try taking the Barlow out altogether for the 850 and CH4 next time as ive not been happy with either of them compared to my IR742 which always seems to do a better job, and there isn't as much detail to capture in CH4 anyway Lee

Hmm some mixed info going on there John, a 150 mm scope won't be able to handle as much magnification as a large scope anyway, so we have to be careful about recommending an optimal f ratio for a given camera. but all depends what Barlow you would be using, its not like deep sky where you can match the camera to the scope, its more about matching the camera to the FL its operating at depending on the Barlow, or look at it the other way around adjust the focal length with different Barlows to match the FL to the pixel size of the camera. I use both a 224 and 462 with my 12"SCT I have to vary the focal length with my Barlow spacing depending on which cam im using. the 224 needs about 8000mm FL to get same pixel scale as the 462 at 7000mm FL.

I saw a used one the other day but can't remember where

https://www.firstlightoptics.com/barlow-eyepieces/baader-classic-q-225x-barlow.html this is the Barlow I was talking about, gives 1.3x or 2.25x. but you can also adjust that further by altering the spacing

Yes I’ve read many debates on the 5x pixel size but others say 7x. But following Damian Peach’s example he’s normally working his c14 at around 7-8metres depending on the pixel size and likes to cover Jupiters disc with 5-600 pixels so that’s what I’ve been doing and have had good results. If it’s a poor night then I drop down to 6 metres, if it’s a good night then I go up to 7 metres. Lee

im not so sure Geof, depending on the seeing im using my 12" LX200 at between f21 & f25 with the 462. on most nights I find f23 gives the best detail for me, so thats around 7000mm FL, on poorer nights I go down to f21 which is just over 6000mm FL. I have just bought a Baader Q turret 2.25x barlow ( only about £45 ) which seems as good quality as my GSO2.5 App barlow, but has the benefit that the end can be removed and screwed straight into an ADC giving a more modest 1.3x mag so that could be a nice option for you to get just a little more if you don't want to go as crazy on the mag as I am. I think it would get you to about f17 & 6000mm FL which is about the same FL as mine at f21. Lee

Thanks chaps, really quite chuffed with this one. Lee

I guessed it was the 2nd image from the larger scale, to my eye the top image looks sharper I briefly had an ADC in September to use on my 12" SCT but after waisting several nights with it I found that all the captures with the ADC were lacking detail compared to without it, I was 95% sure I had it adjusted correctly as the captures with it showed less colour fringing, but also much less detail, so I concluded that I either had a duff one or the brand I bought was just crap but was able to return it. I don't have much patience with things like this and not enough clear nights to experiment I also tried on Saturn where it did remove the colour fringing, but I feel Saturn is too low for sharp visible light images at the moment anyway so prefer to just image low planets in IR Ive been getting what I think are very detailed Jupiter images without it so am in no rush to get another one. Lee

Nice images Neil, when you say recent brightening , how recent do you mean? I just looked at an IR image I took on the 6th but the whole pole looks dark in that one. Lee

Nice set Geof, what f number are you working at approx? Lee

Just getting around to processing some data from the last month, captured this image of Jupiter on OCT 6th centred on 22:54UTC Meade 12" LX200GPS + 2.5x GSO Apo Barlow @ f25 QHY5III-462C 9 x 60sec captures derotated each one was best 40% of 10,000 frames. Not sure I will be able to improve on this image from the UK, Jupiter is now past its best for this apparition and I dont think the seeing gets better than it was this night in the UK. I may be able to get another 10% out of it if I keep trying different processing, but pretty much hitting the seeing wall now, at least with the 12" scope.

Ive taken so many catures of Jupiter in the last couple of weeks but not got around to processing many of them. Here is a single capture from the Oct 11th taken in Infrared under pretty good seeing. have some hints of speckling in the north Tropical region which Is first time ive resolved that, so not bad for my UK location Meade 12" LX200GPS @ f21 QHY462C + Astronomik IR742 filter