RayD

On 25/09/2018 at 22:13, Andyb90 said:

Hi everyone,

I'm tempted to try the TS Optics 0.79x reducer with my Esprit 80 as it would give f4. Has anyone tried the reducer with this scope? If so it would be good to know about your experiences. 

I'd also be interested to know if anyone has used another reducer with the Esprit 80 and what the results have been like.

Andy.

If you are referring to the Photoline 2" one (4 element) it is a corrector as well as reducer.

9 minutes ago, Jkulin said:

I set SGP to refocus every 1 degree of temperature change and it is really is surprising how much difference it makes.

Spot on, John.  On my Tak I've actually just dropped this to 0.5 degrees (Esprit is still at 1 degree).

6 hours ago, souls33k3r said:

So now i'm at :

1. 54.8 out of 56mm required for my LRGB filters 
2.  55.17 out of 55.7mm required for my NB filters

I can add a 1mm delrin bringing the numbers to 

1. 55.8 out of 56mm required for my LRGB filters
2. 56.17 out of 55.7mm required for my NB filters.

Is this going to be good/close enough?

Hi mate, if you get the overall figure to 56mm you should be good enough.  I found with my Esprit that 0.3mm was about the critical limit that it was noticeable, so if you are inside this, then you should be fine.  However, that was being very critical, so you may find that it will work for you at a slightly higher figure.  Much depends on your sensor size also, and this was with the APS-H, so you may have a little more flexibility.  You also need to consider manufacturing tolerances in spacers and even the sensor position, so you often need to do a little fettling to get it spot on.

Spacing can be very confusing as there are 2 things which tend to get thrown in the pot together, but they are actually totally different; one is optical length, the other is physical length.  Camera and telescope manufacturers tend to talk in optical length, but we want to know how many spacers to add, so we talk in physical length.  

If you imagine a DSLR on a FF with 55mm requirement, and then add a filter.  If some advice you get, where you remove space as you have reduced the optical length is correct, it would be impossible to do this, and you could never have a DSLR on a system with a filter.  In fact, you add 1mm (if using an Astrodon filter).

Don't forget with delrins you can put them at both ends of a spacer.  This also helps prevent it welding, but it won't cause any other issues as it is quite a hard material.

1 minute ago, souls33k3r said:

Shitzer   was hoping that some day i might stick a LP filter in it and start using the LRGB filters ... oh well, you win some, you lose some ... Cheers for clearing that up matey. Muchas gracias

 

You could probably come up with some form of solution to build one in to the imaging train, but not directly on to the FF.  I suspect it would need a bit of a custom adaptor.

4 minutes ago, souls33k3r said:

Also what about provisioning for mounting a 2" filter inside the adapter/FF, is that true that Esprit 100 is the only Esprit size which doesn't have it?

Ah, not sure if it is the only one, but you certainly can't fit a 2" filter on the FF as it is M66.

That top one must be pretty old mate.  I've had mine quite a while, and it's one of the 'older' models, but mine has the bottom case, so I guess all the newer ones will.

40 minutes ago, souls33k3r said:

hang on, you said SPAIN? Well you only have clear skies there

Ohhhhhh if only that were true!  I just had 16 nights there, and only 2 of them provided any chance of imaging.  It's been a shocking couple of weeks, and at one point I was sat there hoping for clear skies, but logged on to my UK obsy imaging! 

Strange world ?

Well I'm certainly as happy as I could be with my latest delivery. Got home from Spain early hours this morning and still woke at 8 as I was so excited to open it. 

I hope it performs as well as it looks because it certainly looks the part. 

This is for the remote obsy in Spain so the through the mount cabling really appealed, and I can't afford a 10Micron or AP, so this was next on the list. 

2 minutes ago, Paul M said:

The posty bought me an early birthday present (we'll be away on the day): an illuminated Moon globe. It has a remote and can change colour etc. Quite effective in a dark room

They're great.  My Godson bought me one as a little fun thing and I love it.  Sits on my office desk.

To me that looks a little like the elongation is bottom left to to right across the whole field, so possibly some tracking issues?  What length subs are these?

I have used CCDI many times, and if you have a read up of the author's recommendations it is quite specific on star field, length and number of subs and orientation.  I think to test flatness of the field you need to totally eliminate any other possibility, so very short subs, and a number of them (20 or so) in a very even but dense star field.

Yes that does point towards a very slight tilt, but the spacing looks to be out as there is a radial pattern across the whole image, just a little more noticeable at the top.

I did a short intro video here showing the option of the screw fit.  This is what I use and it seems to work very well, and definitely an advisably option in my view for imaging.

I agree with mosie, it is probably spacing.  I use the same configuration and you need nearer 59mm between the FF and sensor.  I use all screwed, so long as you pop the FF in with the scope facing downwards and make sure it is nice and tight, then it should work fine.  I've not noticed any draw tube sag as it doesn't need much projection to reach focus.

Start with the spacing and once right (take short subs pointing straight at the Zenith) see if you then have sag.

4 minutes ago, souls33k3r said:

hehehe rubbed it, kissed it, prayed all around it, winked at it ... i hope i haven't missed anything

Yep....Imaged with it ?

1 minute ago, souls33k3r said:

And it's back

Woo hoo!!

Give it a little good luck rub 

The thing that is so odd is that the longer subs are not hugely different to the shorter ones, which pretty well eliminates tracking.  Have a little look at Louise's @Thalestris24 thread posted here where she has a really good video showing quite bad backlash, possibly caused by loose gear retention grub screws or similar.  Maybe try running it out of balance slightly to make sure the gears are engaged only on the driving side which will eliminate potential rocking in the gears.

5 minutes ago, alcol620 said:

Then I move the alt and az screws to get Polaris in the position on the reticle circle that represents the Hour Angle of Polaris?

That's about it.  You can also then rotate your mount through 360 degrees and Polaris should stay on the line all the way round.

It might also be worth just trying some subs with differing focuser orientation.  As well made as they are, my Task FSQ106 does not like imaging with the focuser upside down.

4 minutes ago, alcol620 said:

Ray what would you be looking for with the test shots at the Zenith?

This helps to eliminate draw tube sag and points towards other issues like mating surface not true or sensor misalignment.  Just make sure you are pointing up as close as possible to vertical, and take a few shots around this area.

Not sure if yours is similar to my TS80, but if so it isn't adjustable.

This is mine mounted on my Neewer carbon fibre tripod which was about £70 and it seems to be good at the minute.  I think so long as you can remove the head to screw the mount on, then any tripod that will take the load will do.  The one from FLO looks good, and if you are ordering other stuff then it makes sense to add that to the order.

As Dave says, few ways to attach a guider, but it depends on the guider you are planning, which largely depends on what you are imaging with.  You may be able to use one of the mini guider units from QHY, which are tiny. 

Hmmmmm that looks more like you have 2 issues to me, spacing and tilt.  The aberrations to me look variable across the screen, which they wouldn't do if it was tracking.

I'd take a few very short test shots pointing up at the zenith and analyse those first, as I really don't think tracking is your main issue here at this point.

7 minutes ago, alcol620 said:

thanks Ray for reassurance re trailing rather than spacing, although there looks to be a bit of it too.

Yes you could well be right.  Always hard to fight 2 issues at once, so you are doing the right thing in tackling the tracking issue first.

3 minutes ago, alcol620 said:

Hi Ray

As my earlier posting said, I did find some screws loose, I haven't had the opportunity since to run with stars in the frame - only the 24 hour test performed. So next time out I'm hoping for the best. I know that the TSAPO60 and the ASI1600, does struggle to get round stars in the corners with the flattener/reducer even when great care is taken to get the spacing spot on.

Ah Ok I hadn't realised you hadn't tested since.  If it was spacing it would be different patterns, but this is definitely trailing being across the whole field, either as a result of really bad PA (but I would think it would need to be really bad to show up this much in 30s) or some other mechanical issue. 

Hmmmmm I'm not totally convinced about PA with that much trailing.  I would be checking and eliminating anything mechanical such as clutch slip or a gear key-way grub screw come loose or something similar.

At last my long awaited custom adaptor from PreciseParts enabling me to use my Feathertouch focuser on my Tak.  It took longer to get from Heathrow to my house (10 days) than it did to get from Miami to Heathrow.  £54.04 in charges for the pleasure at this end also (although that was expected so not a problem, but still painful).

Very happy and very very well made.  Let's hope it fits ?

6 minutes ago, moise212 said:

I'm not trying to argue in any way, I apologize if I left this impression.

I was just trying to mention that there are alternatives to some items and this is not obvious at first glance. While the info about the flattener was added indeed by FLO to the site, the info about the other parts I was referring to is only on the forum.

No not in the slightest, that was the furthest thing from my mind.  It's a good thread in general and is giving me information which I never knew on compatible parts too.