ollypenrice

1 minute ago, FLO said:

... but Baader's own website says it isn't in stock and my colleague, James, recalls they said it could be a few months. With that in mind I will put our product page back to 'unavailable'. 

Pity. Because there is clearly plenty of interest. 

Steve 

I was half expecting it to be unavailable but if you get them before TS I'll buy from you, Steve. It's just that mine is a Euro business and staying in the Euro is easier.

Olly

Hmmm, I hope this product isn't 'vapourware!' Just in from Telescope Service:

Dear Mr. Penrice,

The delivery of the following items you ordered 
is unfortunately delayed due to delivery postponed by our supplier:

Product No. 62162 – Baader Ultra-Narrowband 4.5nm OIII CCD-Filter 1,25"
We can probably ship this product on the 01.10.2019

Please let us know how you would like us to proceed with your order.
Should we not hear from you, we will just deliver your original 
order as soon as possible.

We gladly answer any of your questions by e-mail or telephone.

Best Regards

Customer Support Astroshop.eu

2 hours ago, Anne S said:

I've got 2010 vintage Baader nb filters. I'd be interested in how you get on with the ultranarrowband O3. I'd like to upgrade.

Anne

I'll do a comparison as soon as I'm able.

Olly

Just now, pete_l said:

Teleskop Express quote a field diameter of 70mm for their version and 35mm uncorrected.

Well done! I was on their site and couldn't find it. The 16803 has a 52.1mm diagonal so it will certainly need a flattener. I have to say that trying a chip this size in a GSO RC would make me nervous because it is going to have to be in superb collimation and tilt-free to hold up to the edges. However, Harry Page quite rightly called me a wimp in these matters! 

Olly

I guess you've searched for a corrected circle diameter and not found one published. I found none, either, when I looked. No marks for GSO on that one! I don't recall anyone posting images from such a scope on here and I found nothing on Astrobin. You might find someone on CN, perhaps?

Olly

Well, I just pressed the button on this one for the small format rig (dual TEC140/Atik 460/Moravian G3-8300.)  The Moravian already has an AD 3nm Ha in it so the ability to shoot good narrowband simultaneously in both barrels will be very nice. Planetaries do make great targets. I greatly enjoyed doing the Owl even with a rather old Astronoùmk OIII but both that and the Baader 8nm we have in the widefield rig require a lot of processing to hold down the star halos.

Olly

1 hour ago, pietervdv said:

Hi Olly, Sounds like you owe me a beer for this great tip. ? I'll also go for it, I can tweak my imaging train to fit the 1,25" version in. Want to get into the faint planetary nebulae, guess I'll find out what it's worth pretty soon. 

Pieter

Heh heh, I think I can stand you a beer next time! Being from Belgium you really like French supermarket 3.5% lager, no doubt??? ?

Olly

Hi Pieter, I've been waiting for this to appear because, like you, I don't think much of the 8nm one I now have. At this price I think I'll risk it. Thanks for pointing out that it's available!

Olly

13 minutes ago, Alien 13 said:

I am sure that the same was said of photographic plates but look at how a relatively tiny scope can now easily out perform the great 200 inch monsters even with a DSLR.....

Alan

I'm agreeing with you, not saying the opposite. I just think I'll probably die like a dinosaur, that's all!

Olly

I think that history proves astrophotography to be camera-driven...

If I were younger I might think differently but I suspect that I may turn into a CCD diehard dinosaur.

lly

Any telescope only becomes stunning when people have tried them and found them to be stunning.

Olly

Backlash in either axis does matter for guiding. Its negative effects in RA can be reduced by running east heavy and in Dec by being slightly polar misaligned, with only one guide direction active in the guide program. Hwever, a bit of wind can soon catch you out. Best to fix the backlash mechanically.

Olly

If there was no wind and the tripod wasn't sinking into a damp lawn  then, yes, it looks problematic.

Olly

PS It rather looks as if the movement might be jerky. The trails are not smooth but seem to have concentrated points, in the short sub at the left of the trail and in the longer sub at various points along it.

50 minutes ago, Trikeflyer said:

I thought that exit pupil eyepiece (not scope's) FL in mm divided by scope F ratio? Is that what you meant Olly? Or have I got it wrong?

Steve

Sorry, yes, typo. I'll correct it above.

Olly

When trying to split doubles the observer is not looking for an attractive view of the stars but simply for evidence of separation so a very high power may do that. When looking at the moon and planets the objectives are different since we are looking for fine details accurately rendered.

Unless I've missed it the thread has not mentioned a highly critical number which does not derive uniquely from aperture or magnification and that's exit pupil. Certain targets, and most famously the Horsehead, are dependent on exit pupil. (Exit Pupil in mm = EP's FL in mm divided by its F ratio.)

Olly

Edited because I originally said 'scope's FL' in a senior moment!  Thanks to Steve (Trikeflyer) for pointing this out.

Regarding heat, this has yet to do any damage here and we are often in the upper thirties in summer. I just leave things like doors and flaps open and this seems to do the trick.

I just had a long catch-up on this build and greatly enjoyed it.

Olly

I use two of Lucas' Mk1 200 mounts commercially and they just work. The older one is 6 years old and still fantastic. I like the look of this flip-free idea though. This is an exciting new product.

Olly

On 04/04/2019 at 12:49, continuum said:

I have just purchased through Ian King, a QSI 683 wsg which was built by Atik. eather has prevented proper use but attached is a  copy of IC1848 which shows banding on the left. The banding is moire pronounced in the SHo version than on the subs. There has been little processing but subs were Darks subtracted. I shall email Atik to get their view as I would have thought that m y QSI would have the latest firmware.

Ron

This looks like a different issue. You have one dark column rather than a regular banding. 

Olly

Like Dave, earlier on in the thread, the nearest I could get would be with a six inch (ish) refractor with large corrected field. With a full frame camera (or better still one with a 36x36mm chip) you can go fairly wide:

...and with a small pixel camera you can do as well or almost as well as with a much larger reflector on small targets:

Visually you don't have the light grasp for the faintest of the fuzzies but those which it can deliver it can deliver with exquisite clarity and a wonderful sense of immersion in space.

I'm glad the obligation to lose our short FL apo and larger reflector is only hypothethetical, though. 

Olly

The minimum mount is the mount which is a little above the minimum mount you need! But seriously, this really is the truth. If you joined an astrosoc you might find someone who could look over a mount for you. Buying second hand is certainly the biggest way to cut costs. A large majority of the kit I use as an astronomy provider was second hand, including 2xMesu 200 mounts, Takahashi FSQ106, TEC140, Meade LX200 14 inch and DMK planetary camera and Atik 460 CCD. It's all perfectly good kit and no different from new.

The HEQ5 is a good mount with plenty of backup available.

Olly

1 hour ago, RolandKol said:

Why it's so secret?

I am even getting curious

Skipper Billy started it with his submarines!

Olly

Yes, it is worth repeating that mount tops do not need to be level and this can simplify their construction. Polar alignment is not affected though it might need a couple more iterations of drift. Takahshi mounts and tripods have no facility for levelling, just in case you're doubtful about this!

Olly

Well, you have the data! That's beautifully processed as well.

Olly

Firstly I would only add star colour to a NB image which was aiming to approximate natural nebular colour in the first place, probably HOO.

Rather than try to 'fill in' the star colour on the HOO you could use Photoshop like this:

1) Process the RGB, the Ha and the OIII and align them to fit each other. In processing the RGB concentrate on the stars, keeping them small and colourful and don't worry about the nebula which will be coming from the NB layers.

2) Add Ha to red in blend mode lighten, making sure your Ha stars are smaller and fainter than your red stars. (Use multiple iterations of a star reduction routine like Noel's actions or whatever on the NB layers.) save three copies of this. Call this Ha to red.

3) Add OIII to green in blend mode lighten in one of the copies and call it OIII to green.

4) Add OIII to blue in blend mode lighten in another copy and call it OIII to blue.

5) Make a three-layer stack like this:

OIII to blue

OIII to green

Ha to red.

Now you can choose opacities for the top two layers which give you the most natural nebular colour. Your RGB star colour should be unaffected.  As you can see, this method does not work by replacing star colour so it gives a more natural look, yet the NB contribution to the nebulosity is the same.

Olly

54 minutes ago, John said:

I worry a bit when I see scope decisions based on the achivement (or not) of a very specific observational challenge.

Ten members here could say that they can easily see E & F Trapezium with a certain scope, then you get one, and can't make them out. I'm not sure where that has got you ?

 

I'm intrigued by this as well. I have a very dark sky, sometimes reaching SQM22, but the seeing is predictably variable. I have never found E and F 'easy' though this may be me. I'm not a double or multiple specialist. Sometimes I'd call E reasonably easy but never F. Possible but not easy. I've used 10 and 14 inch SCTs, 20 inch Newt, TEC 140 apo, and F has never been 'easy' for me.

Olly