Sorry...I think quoting +/-3 arc sec with PEC is like saying I can see 20:20 with my glasses on. ...but doesn't really tell me how well I can see. ( I recall Meade tried the same trick)
The Vixen Altux is an *excellent* mount.
But it doesn't run at +/- 3 raw. It also costs around $US5000 and (best guess) would cost $US600 to ship to Oz....$A7200 with GST?
The M8 pic was mainly gathered on a G-11/AP155. I did the H-alpha much later (complete with fishing line for diffraction spikes...duh...what was I thinking...) with, and you guessed it, the AP bolted to a very expensive RCOS14/PME...that I use more for faint fuzzies eg:
But, hey, at 1100mm or so, tracking with a self guiding camera is not really an issue.
I also suspect I am being mis-understood here.
All I am saying is most stuff that costs not a lot of $, because it is built to price.
You might get lucky and end up with Herbie the VW....then again no.....
If something is built to a sepcification, gosh, it costs more...but then you have have every right to front the manufacturer if it doesn't perform as advertised.
Love to play with the gear you get! Yes the landed cost of a new Atlux is around $7,200 - but the newest model is delayed and I hear the Starbook it uses is a flashy toy compared to the older SkySensor2000-PC. I would say PE raw is 6-9 arc secs on the Atlux - give me more time to master PEMPro and I'll soon know what before and after is like!
My major beef with the Atlux is its manuals only tell you a good 1/3 of what you need to know - if they re-wrote it or appended what is really needed to set this up and operate it to its fullest capability - I think most folk would be pleased. I love the way I can wake it up, slew to one star and check its spot on - it ifs more that 5 arc minutes out I re-sync, then the rest of my slews seem almost dead centre of chip at 2300m focal length. From power on to imaging is about 5 minutes - and most of that is calibrating PHD! Also they could have done a much better job revealing the SkySensor2000-PC capabilites with better drivers and ASCOM APIs. Not even half of what it can do is revealed via the LX200 emulator it most frequently deploys to.
I think a really level base, good initial GPS co-ordinates for a permanent pier, top quality dovetails (e.g. Robyn Cassidy or Losmandy), setting the motor type relative to load and good polar alignment if you want PEC are all essential to getting the most from this mount. Mind you the mount tracks brilliant on a 3 star align if you're within about 30 degrees of the SCP and set polar unaligned mode (which runs both motors to compensate and account for the air's refractive index by position). So its easy for a first year amateur to start to handle! Mind you its heavy - making the EQ6 look light!
It would be great to see side by side reviews of the mid-to high range mounts. Experienced folk comparing the Paramount and the Tak EM-500, the AstroPhysics 900 vs the Losmandy Titan vs Mountain Instrument 2500, all the way down to the humble CG5.
Brilliant M8 - I think the RCOS 14" goes with the PME as a brilliant couple. How heavy is the 155mm APO btw?
ummm, I dont see the term "PE" or even more important,"non periodic error", without them ,your pissing upwind . On the other hand, if you got pin point stars with a SINGLE 45min exposure, 1/ your in the wrong job, you should be making mounts. 2/ if you can make them that good at less than $20K youd be a very rich man in a very short amount of time 3/ I would grovel in the mud, apologising profusely.
gimme PE stats
I shouldn't be doing this, doesn't do my blood pressure any good.
Go to the library, pick up the book How to make a Telescope by Jean Texereau. Read the chapter on Sector Ribbon Drive. If you then understand the principle of that drive come back and tell me where PE comes into consideration. No offence meant. But I go back 40 years in AMATEUR Astronomy of mirror making, instrument making and deep space photography. CCD imaging is totally new to me. Taking photos of DSO's is old hat.
A few of us old blokes who read, not post, IceInSpace at times are rolling on the floor laughing at the some of the statements made re preccission euipment and that you can't do award winning work without spending tens of thoudsand of dollars.
To everyone who is so concerned about PE, precission and Chinese made Equipment, take a deep breath and then go and have a look at Mike Salways Lunar/Planetary and His START of DSO Photographs.
Then come back and tell me that you need $10000 worth of precission equipment to take award winning astro photos.
If attached thumbnail doesn't explain it enough let me know and I will try to get a close up of the cradle by itself.
Hi Aster, thanks for the pic. That's a huge scope. Do you have a couple of photos of nebulaes to share with your current rig? Just want to check what kind of objects you can take photos of with a large diameter?
On my experiences with 35mm film and CCD astro photography
Quote:
Originally Posted by Aster
>snip
But I go back 40 years in AMATEUR Astronomy of mirror making, instrument making and deep space photography. CCD imaging is totally new to me. Taking photos of DSO's is old hat.
>snip.
Hi Alexander
Nice to hear about your experiences and see a photo of your rig – both are quite impressive. Not too happy to hear about your blood pressure though – take it easy, we’re a friendly bunch here all doing the same thing and trying to help each other by sharing our experiences; whether long or short; correct and sometimes not so correct; often wise but occasionally naïve!
Anyhow, I have dabbled both in 35mm film and CCD astrophotography; not as an accomplished practitioner, more as a recreational amateur, for enjoyment and at times, relaxation. The demands on my mount, skills and technique were noticeably increased when I migrated from 35mm film DSO photography to CCD DSO imaging.
I used to attach my Pentax 35mm film camera to my 200mm F9 cassegrainian. Using an off axis guider (with built in x3 Barlow), I was able to keep a guide star centred in the (small) inner square of a 9mm illuminated cross hair guiding eyepiece and achieve round stars (mostly) through making manual guiding corrections on a Vixen GPDX mount. This was done by eyeballing the guide star in the reticule and pressing the Up/Down Left/Right motor movement buttons at a guide rate of x2 sidereal to keep the star confined in the square. Generally, a 30 minute session wasn’t too demanding, but once I headed into 45 and 60 min territory, boy it was tough work!
When I replaced the 35mm film camera with a CCD camera this technique proved impossible – I just could not get un-trailed stars using this set up. I would estimate that the CCD camera was some 3 to 4 times more sensitive to guiding corrections than 35mm film. I know that a few here, such as Scott (Adler) and Paul (Mayo) have manually guided DSLR’s, but very few have the will power and stamina to do that these days, so they resort to auto guiding.
Cheers
Dennis
PS – I know you are intimately familiar with much of the above re film photography, but I have included my experiences for those readers who will never experience film astro photography, as the digital age is well and truly here.
PS – I know you are intimately familiar with much of the above re film photography, but I have included my experiences for those readers who will never experience film astro photography, as the digital age is well and truly here.
Hi Dennis,
When this years comet rekindled my interest and I started to dabble with the DSI Pro, then started to stack a few images etc. my Wife said, THAT IS CHEATING.
I remember sitting on top of a 6 foot stepladder, eyeballing the dim star in the OAG, trying to see if I have to push the dome a bit more, in the process nearly falling of the stepladder. Or dozing of after a hard days work and spoiling 30 min of guiding. Hmmmm, was that the time when we were True AMATEURS ??? Couldn't purchase equipment we wanted here, importing was out of the questions for most of us. So we looked at the pictures in the astro magazines and tried to make them ourselfs.
Only looked at a stack of old black/white photos with some visitors the other day and they couldn't believe that we did things like that 30 odd years ago. Couldn't get over how sharp and clear the images were with home made equipment and without automatic guiding
Anyway, nice to see that there still are some around who have done it the old way.
Hi Aster, thanks for the pic. That's a huge scope. Do you have a couple of photos of nebulaes to share with your current rig? Just want to check what kind of objects you can take photos of with a large diameter?
If you go to the Deep Space forum and search for Aster you will find a couple of feeble attempts. Totally new field to me, CCD imaging.
To everyone who is so concerned about PE, precission and Chinese made Equipment, take a deep breath and then go and have a look at Mike Salways Lunar/Planetary and His START of DSO Photographs.
Then come back and tell me that you need $10000 worth of precission equipment to take award winning astro photos.
Thanks for the vote of confidence, but my DSO stuff is a long, long way from being award winning. I'm not even in the same ballpark/country.
But you only need to look at Gary Hill's, Scott Alders and Eric (EzyStyles) (as 3 examples) of very good (and award winning in the case of Gary) DSO photography on a budget.
Guys,
this has been a great tread, i love a good old fashion punchup!
I've learnt alot about mounts in a very short time
answer is.......each to thier own... everyone wins!
thanks
Alex's argument reminds me of an old gag...guy goes to a tailor and is fitted with the worst cut suit ever. Goes back to the tailor, who gets him to contort something like Quazimodo to make the suit fit. Guy leaves the tailor shop. Couple sees this poor bugger limping down the street, "Oh look at that poor cripple she says". " Yes he replies, but sure is a nice suit!"
Images that show elongated stars, noise, weird colour, and poor saturation might give some people a warm and fuzzy feeling (and hey this is good) but can be a little ho-hum for those wanting to push the envelope.
And it gets harder to avoid all of the above as you extend the focal length.
Deep Sky Imaging at 3000+ mm is downright demanding. But so far I haven't found a $1299 system that cuts the mustard...but am always on the lookout for excellent work that makes the suit fit.
Just to add some fuel to the 'cost of success' arguement. These images were taken by year 8,9 and 10 kids at the school where I work none of which had any experience in imaging. They were imaged with the Faulkes telescope at Siding Spring Obs.
I think they are very good.
I hate to think of the cost of the instruments they used.
Mike Salway does indeed do excellent planetary work but the required equipment and techniques are *entirely* different to long focal length Deep Sky imaging....which was still is my point...and my apologies if this was not made clear.
Bert held up some good examples, but at FL 300mm? Hardly a tracking challenge (but, sorry, the stars are square. Please compare them to those here:
O.K. so here's my current GEM pecking order, taking into account cost vis tracking accuracy and payload.
Paramount PME, Losmandy Titan, AP1200, AP900, Taka EM400, Taka EM200,
Losmandy G-11, Vixen Atlux, Vixen GP-DX, Losmandy G-8, Taka EM20, Taka EM10/11, Vixen Sphinx, EQ6, EQ5 (and Synta equivalents).
But, hey this is a very subjective call and I think some of these mounts are not made anymore..
Then again...what would I know...
Cheers
Peter
Interesting Peter. I don't think I'd rank the Losmandy Titan 2nd on the list. Don't get me wrong, its a nice mount, I had a C11 on it for sometime and it was "hit and miss" at 2800 focal length so doubt it would handle a 12.5" RC very well. I think I'd probably sell mine and go with an AP1200 or if feasible a PME. I recall you were operating the HGM200 with an RC for sometime. This is a different beast to the Titan of today as I understand it.
This thread clearly indicates a "horses for courses" principle. Ask yourself what you want to achieve in this hobby. Be realistic when entering the imaging realm. Use equipment that will meets your goals. Be it a 50mm lens mounted on a little GEM or a 24" RC on a eq. fork. The type of equipment you use does not determine if you're a professional or an amateur. Its what you do with the collected data that distinguishes this.
Also it depends how old the Titan is. The current crop have changed to Phosphor bronze worms and there have been a few other tech changes. I understand the last production batch had +/- 3 arc sec raw PE as a result....
That said for heavier payloads, I would in fact pick an AP1200 any day. While it is priced a good deal more it is physically larger and will indeed hold significantly more telescope and return a similar level of tracking performance.
Steve Crouch is using my old HGM200 these days and getting some great results from it....in fact I miss some aspects like being able to track for hours past the zenith which the PME can't do.
But I agree entirely, with the "horses for courses" summary. You'd be nuts to think a PME is required to adequately point a 50mm camera lens when an EQ3 would easily to the same job.
. On the other hand, if you got pin point stars with a SINGLE 45min exposure, 1/ your in the wrong job, you should be making mounts. 2/ if you can make them that good at less than $20K youd be a very rich man in a very short amount of time 3/ I would grovel in the mud, apologising profusely.
The list
