Louis D

If you go out to SearchLight Spectra Viewer and select the Astronomik and TV Bandmate II OIII filters, you'll see they're basically the same.

Add in some other OIII filters, and you'll see that these and the Chroma are a cut above the rest.  The Lumicons are as good in the OIII band, but bleed red.  I can vouch for this.  My 1990s Lumicon OIII shows OIII emission lines really well (no rust, thankfully), but bright stars have a weird green/red duality that I find distracting.

I wonder if my cheapie Zhumell OIII is like the StarGuy OIII and passes C2 comet bands as well.  The SG OIII is nearly identical to the Lumicon comet filter.  That would be neat to have gotten a comet filter for $16 because it makes for a pretty poor OIII filter. 🤨

Another diagnostic tip is to defocus the star and observe the undulations on a larger scale.  Put your hand in front of the objective and you should see heat waves emanating from it.  Remember, we're looking up through many miles of thick atmosphere that has all sorts of currents and bubbles in it.  It's one of the reasons professional observatories are placed high up on mountaintops that have fairly laminar airflow over them year-round.

And the AZ-GTi has a Point and Track mode that doesn't require prior alignment if goto is not needed (as for bright solar system and DSO objects) and the mount is well leveled.  That alone sounds very useful for high power observing.

Alignment of my Dob's DSCs can be an issue for me due to the narrow swath of sky I can see from my backyard.  I use the app SkEye to get me in the ballpark of dim objects since it relies solely on internal sensors.  It gets me close enough to know if the object is even visible at that time for me.

On 29/01/2022 at 08:07, DamianL said:

I don’t know how to do timestamps in YouTube links

It's pretty simple.  Just pause the video at the beginning of the section you want to highlight, right mouse click over the video, select the third option down (Copy video URL at current time), and paste that URL.  You could even edit your post above to fix this by clicking on the three dots at the far right of the gray bar with your user ID and post timestamp, selecting Edit at the bottom of the list of options, delete the original video inserted and paste in the corrected URL, and then fix up the text since you now know how to do all this. 😀

You'll definitely want a side mounted alt-az for visual use, as long as you don't mind manual tracking.  I've tried using a fluid head on a photographic tripod for astronomy with an ST80, but beyond a certain point vertically, the telescope tips back uncontrollably.

4 hours ago, LaurenceT said:

Astronomik have 2 UHC offerings, the UHC and the UHC-e. There is a considerable cost differential between the two, is this borne out in the observing effect?

From my understanding of their offerings, the UHC-E is a bit cheaper because it has a wider passband around the H-β and O-III lines than the UHC.  The general rule in passband filters is, the narrower the passband, the more expensive the filter, all other variables being equal.  The UHC-E also seems to pass a bit less of the H-β and O-III lines, but you'd be hard pressed to see this difference visually.

Astronomik also recommends the UHC-E for 5" and below telescopes and the UHC for larger scopes; although if you have both, I would get the UHC.

In use, having a narrower passband will eliminate more light pollution and sky glow.  This will in turn increase contrast making nebula features easier to see.  At a dark sky site, this would be of less importance.

UHC-E:

UHC:

Astronomik points out that the UHC-E filter passes at least one of the C2 carbon lines at 511nm and 514nm associated with comet filters like the Lumicon Swan Band Comet filter.  Thus, it might serve double duty.  I'm kind of surprised they didn't include them in the UHC-E passband image above for positive marketing purposes.

Lumicon Swan Band Comet Filter:

9 hours ago, 900SL said:

I remember when 'justintime' started and manufacturers jumped on board to cut inventory and warehousing costs.. 

Famous last words:

14 hours ago, Roy Cropper said:

Its not just chips. It's wood, building materials, steel,  all worldwide.  I'm  looking at ordering a new car and I've discovered theres a shortage of leather for trimming the so many now only come with the bits you sit on in leather and the sides and rears in faux materials.

It's a perfect storm of supply chain inconveniences. Covid affecting both production and supply chains, several massive building projects worldwide sucking up resources - including HS2 in the UK -, significant changes in demand due to different working patterns, and dozens of other factors. The ripples will be felt for a few years yet.

Absolutely correct.  I just don't know the details involved in other industries as intimately as I do semiconductors.

Stacking an OIII with a UHC will just pass the OIII lines if the UHC was designed correctly.  Of course, if the UHC passes OIII less efficiently than the OIII, the OIII lines will be dimmer.  If the UHC doesn't pass OIII (they all should, but some are off a bit), then you'll see basically nothing.

Short answer, don't stack nebula filters.

You can stack other filters types like the moon & skyglow filters with a yellow filter to more strongly cut unfocused violet light when using an achromatic refractor.  The combination can improve sharpness a bit in that usage case at the cost of some blue light.

The Technosky is Long Perng made, I believe, and many reports are claiming better quality control, consistency, and spherical aberration correction than the Sharpstar.  Long Perng is Taiwanese while Sharpstar is Chinese if that matters to you.  Even then, it's likely Long Perng sources some parts from China.

I have the older TS-Optics Photoline 90mm APO FPL-53 triplet for visual use, and the rear end of it looks almost identical to the 94EDPH.  They use really beefy thumbscrews that seem to be solid steel or brass instead of pot metal.  The machining and fit of everything is first rate as well.  I really like the camera angle adjuster for aiming my diagonal off to the side without loosening the retention screws or rotating the focuser.  I haven't tried removing the rear tube section to use binoviewers natively yet, though I'm sure it works fine.

Now my peeves with it:

It annoys me a bit that it shows spherical aberration on one side of focus.  I get a nice Airy pattern on only one side of focus.  The other is just an even blur.  I guess we'll leave it to AP, Tak, TMB, TEC, and LZOS to nail that detail.

The focuser is a bit mushy under heavy loads as well.  I have to overshoot best focus a bit near zenith with a 3+ pound load in the focuser because the fine focus knob tends to counter rotate a fraction of a turn once let go of.  This might not be an astrophotography issue with a motorized focuser, though.  I don't know if it would be up to the task of demanding AP.

It also shows pinched optics while acclimating (spiky stars).  This can take 30 minutes or more to settle down.  Again, I find this annoying in a smallish refractor.

False color seems well controlled in focus even on bright objects.  However, it shows green tinge on one side of focus and red tinge on the other, so it's no reflector.

Otherwise, it's been a decent enough visual-only scope, but it's far from what I would consider perfect for visual use.  Would it be good enough for AP?  I can't say.  For what I paid used for it, I can't complain too much.  It was way cheaper than an AP Stowaway.

I use a 6" long bolt of the same thread as a threaded hole on my DSV-2B mount with about a pound of washers I had laying around hanging off the end of it.  It swings up to horizontal when the mount is at zenith to partially counteract the effect of the eyepiece in the diagonal.

If you don't have strong astigmatism in your eyes, you don't really need to wear eyeglasses with binoculars.  Sure, leaving them on can speed up looking at the sky naked eye, and then quickly switching to binoculars without having to take off your eyeglasses first.

To diagnose your issue, take off your eyeglasses and then start by focusing the binoculars by closing the eye with the diopter adjustment and focusing through the other eye.  Next, close the first eye and use only the diopter adjustment to focus for the other eye.  Now open both eyes.  You should see two equally sharp images.  If you have astigmatism, you'll see a slightly blurry image in the daytime or spiky stars at night.

Now, close alternating eyes and see if the image jumps between two positions or remains stable regardless of which eye is viewing.  If you see the image jumping about, your binoculars need collimation.

Put your eyeglasses back on and repeat the above steps.  Do you see any differences?

There is a very slight possibility that your eyeglasses have prism correction which allows you to merge misaligned images naked eye.  However, you'd probably be well aware of it since it is usually diagnosed at a young age.  That, and you'd see double images without eyeglasses or binoculars.

5 hours ago, O2B3 said:

Which 3 eyepieces can you recommend are best ,to use with my skywatcher200p 

Mark

What's your budget?  What do you like to observe?  Do you have strong astigmatism in your observing eye?  What eyepieces do you already have?

Your question is a bit too open ended to make any specific recommendations beyond getting low, mid, and high power eyepieces to cover a broad range of objects.

Having worked in the semiconductor industry for 35 years, I can explain a few things about chip costs and manufacturing.

Chips were cheap when they were small and contained relatively few transistors.  Practically any company could afford to make them.  However, you could forget about portability or battery power for all but the smallest of chips.

People demanded more functionality in smaller and more power efficient packages.  This necessitated more transistors and larger chips.  This also necessitated shrinking transistor sizes.  This increased manufacturing costs and startup costs.

Chips being more complex required more and more process steps to complete them, requiring longer and longer manufacturing times.  If you cancel an order today, it can take 9 to 12 months or longer to get back in the queue during good times.  Automakers and others foolishly cancelled chip orders early on in the pandemic due to a panic reaction, not fully realizing the consequences of their actions.  Foundries simply filled those manufacturing slots with orders from further in the future that were going to wait for the automaker orders to complete.  PC, laptop, and tablet sales and semiconductor orders skyrocketed, more than making up for the lost automaker orders.  Future slots filled up fast.  The automakers and many others were shutout in the near term.

Fast forward to today, and it costs 7 to 10 billion dollars to build a cutting edge semiconductor foundry to manufacture chips.  Even mighty Intel is struggling to keep up with Samsung and TSMC (the two largest leading edge contract chip houses or foundries).  All the other leading edge legacy chip design houses have sold their legacy foundries and have gone fabless (outsourced their chip manufacturing).  Most legacy fabs in the US are owned by Global Foundries.  These legacy foundries make "good enough" chips for many purposes, but at an elevated price per part at yesterday's performance and power levels.  The US military is one of their biggest customers since they try to source as much from within the US as possible.  One problem for the US military is that there are no microprocessors made in the US anymore.

Unless governments such as China and the US are willing to subsidize new foundries in their own countries, it's unlikely this consolidation of semiconductor manufacturing will change.  You have to be able to sell billions of chips per year to recoup your foundry investment costs.  This requires taking in orders from outside of your own company even for companies like Samsung that sell hundreds of millions of consumer products a year.

Even building a small custom chip requires a $10,000,000 up front cost for manufacturing setup and reservations.  Thus, a lot of companies are moving toward FPGAs for low volume (less than 10,000 units or so) production.  These chips are programmable but cost more per unit on a gate level functionality basis.  It might cost $100 to $2000 for a single FPGA that a custom ASIC in full production volume might cost $5 to $100.  However, if you amortize in the setup costs, they come out cheaper for low volume production.  FPGAs are also larger, hotter, and draw more power than their ASIC equivalents, so they're not a drop-in replacement for all applications.  Also, no FPGA can hold an entire cutting edge microprocessor's worth of gates or run at their elevated clock speeds.  Thus, FPGAs are best for smaller designs and/or coprocessors to offload compute intensive operations from the microprocessor.

Well, I find the jump from 1 degree to 1.7 degrees with a 40mm SWA 2" eyepiece quite nice in my 127 Mak.  It's not widefield like a 72ED frac, but it does help with getting targets centered and for showing better context since it reveals 2.9 times as much sky by area and 70% more by linear measure.  Since I already have all the required bits, it seems silly not to use them just to remain a 1.25" purist.  That, and I can use my ES-92 eyepieces which are 2" only.

10 hours ago, Mr Spock said:

The semiconductor shortage is the reason why you can't get new cars. 

I realize that.  It's also why a lot of products with microelectronics in them are delayed.  There's also a shortage of workers around the world slowing things down.  A lot of folks took early retirement, older workers don't want to risk getting C19 and so aren't working or are working other jobs, and still others became self-employed during lockdown.  China is experiencing an energy crisis as well that is affecting factory production.  Texas had Snowmageddon last February that impacted petroleum refining and chemical manufacturing.  This then impacted other manufacturers like foam producers which impacted mattress and seating manufacturers.  The ripple effect is still sorting itself out a year later.  It's been a perfect storm of events leading to the current supply chain crisis.

3 hours ago, PeterC65 said:

The second eyepiece I bought was a 40mm Celestron Omni plossl which I don't use much.

Didn't you say you added a 2" Clicklock to your Mak in another thread recently?  Do you have a 2" diagonal and any 2" eyepieces for it yet?  Here's my setup with a 2" visual back and large 2" eyepieces.  The first photo has a decloaked Meade 40mm 4000 SWA in the diagonal while the second photo has a 35mm Baader Scopos Extreme in the focuser.  The 40mm Pentax XW would probably do well in it, but I haven't tried that combo at night since getting the XW a over a year ago.  I did take a snapshot with my cellphone camera through the combination as shown the third photo.  It's lighter than either the Baader or Meade.

I find fine focusing with the foam wrapped focus shaft on the 127 Mak easier than fine focusing with my single speed Crayford focuser on my Dob.  It's very smooth with next to no backlash or mirror flop.  The Crayford is a bit notchy due to the high preloading on it for heavy loads.  Thus, it takes a bit of grip on the knob to get it to move.

I love the fact that none of the visual back's load is transferred to the focusing mechanism.  It's all born by the rear cell which does not move during focusing.  No matter how much load is on the Mak's visual back, focus feel remains exactly the same.  It's such a refreshing change, especially from the fracs' focusers which can struggle at high altitudes under heavy loads.  The Dob's focuser load doesn't change much with altitude by comparison.  However, once I've got a Barlow, PBI, CC, and 17mm ES-92 in there, it starts to feel a bit boggy.

Starting out, I'd go for one of the cheaper zooms plus a 32mm Plossl for widest field views.  At f/12, all would perform excellently across the field.

7mm to 8mm is about as high as you can go on a 127 Mak due to small exit pupil issues anyway, so it's a good fit for the Mak.  Technically, you could go all the way up to an 84mm eyepiece for a 7mm exit pupil, but such a 1.25" eyepiece doesn't exist; and if it did, it would be like viewing through a straw since it would have about a 20° apparent FOV.

4 hours ago, Beardy30 said:

I want a quick simple set up

I just carry my 8" Dob outdoors in one go snugged up against my body using carrying handles on either side of the rocker box.  Next, I remove the Telrad from its storage box and attach it to the tube.  I then remove the scope's end caps and check collimation (usually still spot on), and I'm good to go in under 2 minutes.  Of course, it needs to cool down, so I do this 30 minutes to an hour ahead of time.

For the Mak or frac, I have to get the tripod out, spread the legs, level it, get the scope out of a case, attach it to the mount head on the tripod, remove end caps, retrieve diagonal from OTA case, remove caps, insert it into the scope, retrieve and attach a Rigel QuikFinder, lock the axis clutches, carry the top heavy tripod/mount/OTA combo out the backdoor, and set it down to let the OTA cool.  This takes no less than 5 minutes.  Honestly, I much prefer the Dob; but I do use the others just to mix things up a bit.

The Dob has much less assembly required and just sits at the back of the coat closet upright and out of sight.  The collapsed tripod/mount combo is tucked in toward the front corner of the coat closet since it is much slimmer.  The Mak and frac cases rest on the floor at the back of the closet in a stack.  The Mak/frac/tripod/mount combined take up less space than the Dob, but each has a much smaller aperture, so is it really a fair comparison?

I do like the DSCs on my Dob, but they're a pain to align because I have been reduced over the years to a narrow sliver of southern sky due to tree maturation in my backyard.  I generally can't see two bright stars at the same time, so I guesstimate on Polaris, align on a bright star, and then refine the alignment on easy to find objects like a planet or bright DSOs.  I've found SkEye on the smaller scopes to be really helpful since it needs no alignment and gets me within a few degrees every time.  It would be neat if the developer added plate solving using the camera and a 45 degree mirror like Celestron's StarSense.

Of course, I've learned to make do without tracking over the years.  I did make a crude, homemade EQ platform early on, but it was just one more heavy piece to carry out each time to observe, so it became scrap.  Perhaps an integrated aluminum one would be acceptable to me now.

Amateur astronomy is a journey, and preferences can change over time.

About a decade ago, someone local here was selling a complete Meade LX200 10" with field tripod for $400 on Craigslist, and no one would bite.  Maybe in today's used market environment you could get a decent price for it.  Big SCTs, like big Dobs, don't have good resale value compared to APOs and smaller scopes.

Do you like goto because you have difficulties finding objects or because it tracks or both?  You could always put DSCs on a Dob to find objects and the Dob on an EQ platform (with the DSCs in tracking mode) to get both with a large aperture.

I'm hearing that semiconductor manufacturing probably won't sort itself out until well into 2023.  I figure that most other industries are in a similar condition.  I'm glad we bought a new car in July 2020 despite the raging pandemic while inventory was still good.

And even the new ones can be converted back to the old Mak thread size by simply unscrewing the included SCT adapter ring.  The 127 Mak I bought for my daughter came this way.

20 minutes ago, banjaxed said:

I fitted a diy focuser motor to my 127mak and it is the best mod I have done because you don’t have to touch the focuser which negates any vibration.

What exactly do you use for a controller since it isn't shown?  I'm presuming a home-brew box with buttons or a switch and batteries?