jonathan

I gave this my best shot...  Removed my blue filter today, started off with lens cleaner, didn't actually shift anything except perhaps some powder residue on the outside surface, then I moved on to bathroom shower soap scum and limescale remover (spray bottle), soaked the filter in some of that for a few minutes at a time to see if there was any change, leaving it longer each time, couldn't see much change.  So then I went all in, Harpic Toilet Cleaner with Limescale Remover (contains hydrochloric acid!)... I left a thin layer of it on the worst side but it didn't seem to have any effect at all after 30 minutes or so.

I cleaned the lens off and in the end I think all that was going to come off did come off, I'm left with what looks like an etched-on stain on one side (the inside), the outside surface almost looks clear except for two faint patches.  It's certainly far better than it was, the stain is more like a watermark on a piece of paper than a fungus so doesn't interfere all that much, but doubtless it has a small effect.

I have put the lens back in place (carefully, and including the blob of silicon sealant), gave it a go - wow what a difference!  The orangey red background is mostly gone, prominences can now be clearly seen against a 90-95% black background.  Thinking about it, the surface contaminant must have been dispersing the red light from the sun across the filter surface, resulting in low contrast and a redish background.

The filter still needs to be replaced (I didn't have any white vinegar to try, other than that I don't think there's anything further I can do to clean it, unless there's some nasty chemical I don't know about) so one way or another I'll do that soon enough.  I am a little concerned that the inside surfaces of the diagonal seemed to have the same sort of mineral deposits, I do wonder if fitting a new filter will only be a temporary solution and the real problem lies with the diagonal itself.  The red filter and mirror appeared to be fine though.

Oh and just incidentally I confirmed that the original case does contain a sachet of desiccant, has done since new, so I don't actually think keeping the diagonal in a separate tub with it's own desiccant would help that much (probably just end up getting damaged).

OK, I checked and it's the blue lens at the front end of the B1200 blocking filter diagonal that has clouded up with residue / deposits of some kind.  Email sent to Lunt so we'll see if they get back to me in the next day or so, otherwise I might as well go ahead and try the cleaning suggestions from that other thread, they don't sound too hard to do.

1 hour ago, laudropb said:

The proms were quite clear here. The seeing was really good and I think this might have made the difference.

Just confirmed it's a problem with a filter in my solar scope, will need to either clean it or get a replacement.  I suppose I have no excuse for not fixing it (or attempting to) at the moment, having some time on my hands!

On 17/04/2020 at 17:08, tooth_dr said:

@symmetal Alan thanks for the cleaning tip in the thread. I used some bathroom limescale spray, let it soak for a bit, and washed in soap and cleaned with Baader wonderfluid.  Looks as good as new.

Could I ask what brand / type of limescale remover you used please?  I might go down the cleaning route for my own blue glass filter.

I have been pointed to this thread as I have experienced the 'lack of contrast' in my LS60 (in my signature), upon checking the blue front filter glass I found that it was covered in a thin layer of some sort of hard deposit, I tried to remove it using Eclipse Optical Cleaning Fluid and a Pec Pad but this didn't do much, Baader Wonder Fluid took a lot of it off but not all, and this only made it more obvious that there was even more on the other side of the glass than on the outside.  Seeing as it's limescale remover that seems to do the trick to remove it, I wonder if it's some property of the glass that attracts minerals from moisture in the air and ends up growing on the glass surface like some sort of stalectite.  Ho hum!

As with others, my scope has been kept in clean dry conditions in the house, always in it's original foam-lined case, and only comes out on bright sunny days so the chance of it being condensation as might happen with a night time telescope are practically nil, although the idea of storing the diagonal in a plastic tub with some dessicant might help in as much as the atmosphere in the tub should be very dry, giving any airbourne minerals much less chance to deposit on the glass.

It could also be an effect similar to superglue, that can leave a white deposit on surfaces near where the glue is applied (no doubt it's the vapour), perhaps the deposit comes from some other component, paint, or glue used during the manufacturing process.

I have emailed Lunt to see what their advice is, and how to proceed.

1 hour ago, AdeKing said:

If you've not used it for a while, then you could check the blue ITF filter on the eyepiece side of the blocking filter diagonal, these have a habit of going cloudy.

If it's gone cloudy, you can either order a replacement from Bresser Europe or if you're happy to carefully remove it by unthreading the retaining ring then you could spray it with some Viakal limescale remover leave it to do its job for a while then rinse it off and gently clean it with Baader Wonderfluid.  

See thread here.

That sounds like an avenue worth investigating!  So long as I can't damage the filter by using chemicals...  I might email Bresser Europe first to see if they're able to send out a replacement lens (after I confirm if that is the problem).

Thank you all for your replies!

25 minutes ago, Davey-T said:

As mentioned the pressure tuner may need regreasing, mine stopped working after being unused for a while.

Dave

Hmm, I can definitely hear a brief hiss when I release the pressure tuner all the way (I don't remove it, but it comes to the end of the thread), perhaps it could do with a bit more grease though - will any normal car grease do? 

I'm hesitant to remove the PT completely, is it safe to remove and inspect?  It does appear to work still (gets stiffer as I tune inwards), difficult to tell how well though with the contrast problem.

I may be imagining things, but I've used my solar scope so little in the past three years that I've forgotten what it's supposed to look like, I'm sure I remember things being much sharper, clearer, and with greater contrast when we had all the solar activity before the minimum.

Presently when I view the sun through the scope I get quite a light red background in the eyepiece, almost like when there's a full moon, the proms are barely visible against it and I don't seem to be getting much granularity or filaments (feels like the contrast is missing).  Is there something I need to check on the scope?  I appear to have misplaced the instruction manual, perhaps there's something I'm not doing right during setup but I really can't think what.

I've tried different eyepieces so I don't think that will be the problem.  Check my signature for the precise model.

I had a look using my Lunt 60 but they seemed very faint, perhaps my contrast is out as I seem to have a very red background in the eyepiece.

9 minutes ago, Freddie said:

The GONG website gives Ha views of the sun updated every minute.

https://gong2.nso.edu/products/tableView/table.php?configFile=configs/hAlpha.cfg

That does give some nice views showing prominences, thanks! 

Just tried checking the sun's condition using this iPad app that I've used for years, it takes data from SDO (I think) which appears to be fine so I'm not sure what's wrong, has this happened for anyone else?

The actual error is 'Fehler 404 - nicht gefunden!' which translates to 'Error 404 - not found!'  Makes me wonder if the app developer's website is down (or been shutdown).

Anyone know of a good alternative iPad app for watching the sun?

With most of the air fleet grounded and weather patterns stabilised (they are here at least) perhaps it's the best time ever to launch stuff at the moment.

I really must get my solar scope out on one of these 'wall to wall' sunny days this coming week! 

After fitting a 2" diagonal, dual-speed focuser and 2" eyepiece to my 8" SCT I found that it was rather over the intended weight limit of the original mount, I had to abandon it in favour of an NEQ6 Pro.  It would also hit the mount when approaching the zenith, not good for a GoTo.

I considered a counterweight too but ultimately I think the extra weight would just put more strain on the motors trying to shift the weight around (or would in my case - the single arm Celestron GoTo mount that the 8SE came on).

Not sure on the 12" but the 8" should be quite comfortable on a 5EQ, the NEQ6 Pro is a bit overkill but has zero wobble!

There's also the SkyTee Alt-Az mount which should be able to cope (10kg per mount point), it's not GoTo though AFAIK and you'd need a suitable heavy duty tripod.

Did I hear somewhere that this could be a Chrome problem?  Maybe try a different browser to the one you're currently using (be it Chrome or otherwise), see if that helps.

When I cleaned my primary I just placed it on a face flannel in the bath and used a warm shower to rinse, then very lightly moved a blob of soapy (washing up liquid) suds around the surface with my fingers, rinsed, then used de-ionised water for the final rinse.  I didn't have any streaks after that.

I would suggest that you have another go with the soapy suds, don't bother with a cotton bud, just use a very light touch with your fingers (no pressure at all).  De-ionised water again, but leave it at a 45 degree angle somewhere warm on a towel.

Examine the mirror before fitting, flash photo it if you like to check for invisible streaks.

EDIT: Kind of surprosed you haven't flocked the inside of your tube, I did this on my Skywatcher 150P and I think it did make a slight noticeable difference in contrast, must surely be worth while for an imager?  I concentrated on the upper area near the secondary mirror (also flocked the edges of the secondary) so probably almost half of my tube is flocked.  Trick is to vacuum it (gently) using the brush attachment to pull out any loose flock bits before use.

Darn it, considered getting my solar scope out this afternoon as well but had a case of CBA.

Or at the bland pre-recorded dross or depressingly one-topic news on TV.

1 minute ago, JamesF said:

Well, closer to 49% of it, actually

But no, you possibly won't have seen 98 of them because IIRC a few are dependent on libration -- the Moon doesn't consistently face us exactly in the same orientation, but "rocks" a little.  This means that sometimes the objects are visible given a suitable phase of the Moon, whilst others may actually be facing away from us and not visible at all.

James

I meant 98% of the earth-facing surface.  I had thought about libration actually but didn't include it in the quip.

13 minutes ago, Kn4fty said:

Try knocking out some of the Lunar 100. Always a good time!

Rob

Tonight I must have seen 98% of the lunar surface, does that mean I've "seen" 98 out of the 100?

I tried my 3.5 Pentax with 102 refractor, a very good combo for planetary so I'm led to believe however atmospheric disturbance was against me, just couldn't get a decent look through all the wibbling and wobbling.  At such high magnification I was also getting significant mount wobble when attempting to focus (dual speed, don't have a motorised focuser... yet), perhaps if I can be bothered I'll get the NEQ6 out one evening, it would take an earthquake to make that thing wobble.  Couldn't discern any cloud structures, just bright white (with my ND/moon filter) with a subtle gradient at the crescent terminator.  Still was great to see Venus though, it appeared perhaps 1/4 smaller than the full moon does to the naked eye.

I use a drummer's stool.  It has three fold-away legs with rubber feet, some height adjustment, very sturdy, and no chance of accidentally falling off.  Good for use with long refractors or a large SCT.  I find reflecting telescopes don't usually need a chair if set up for a standing position.

2 minutes ago, Littleguy80 said:

That was with my 10” dob. Had some really nice views with 80mm refractor too. Was using TV Nagler Zoom and some Baader Genuine Orthos. 
 

I have a 3.5mm Pentax, how does that compare to those eyepieces (which I have no idea about)?

18 hours ago, Littleguy80 said:

Funnily enough I’m looking at Venus right now   Trying out a violet filter I just bought to try and see some cloud detail. Venus looks great at 200x magnification. Like a little Moon but without all the surface features   

What scope / eyepiece is that with?  I'm hoping to point my 102 refractor at it probably this evening.

It has to be aliens...  or just one, called Elon.