jetstream

2 hours ago, Alien 13 said:

You mention a tablet there, can it run the required capture software?

No idea Alan, they are 800 miles away atm and I need to find some more things out. I wonder what requirements are needed to run the programs? The nice thing is there is room to grow in many aspects of this project, but I do want early success.

Many many thanks and now its time for me to learn.

1 hour ago, Alien 13 said:

I found this information regarding sensor requirements here, I do think there are subtle differences between astro and microscopy cameras due to the latters requirement to take dimensional measurements in some applications. The big plus with microscope optics is that they nearly all follow a strict DIN standard so camera compatibility is easier to get right.

Alan

Perfect and thanks Alan, you obviously have this stuff figured out- very nice image of the slide in the other thread. Much to read and learn now, great info on Nikons site.

1 hour ago, vlaiv said:

Not sure what the question is,

Me neither lol!

I'm trying to figure out a nice USB microscope set up for the 10 yr old grand daughter, who has an interest in science, geology etc and I want to fan the flames with easy,early success and with a touch of "tech".

Thanks much for the info- I was actually wondering about the advertised 5mp and it seemed low on pixels to me, but I know zero about this stuff.

1 hour ago, vlaiv said:

3. Image can be viewed on computer screen in few different ways. One of those ways is 1:1 - or 100% zoom (sometimes referred native resolution - yet another usage of term resolution - btw native resolution can mean something else entirely

Ok, some info says the final "magnification" is dependent on the screen size? how so?

she has a small tablet- can this limit the resolution depending on its own screen pixels?

I have piles of questions actually, including how to automatically stack the images taken at different focus points to produce a razor sharp image across a 3d object... one manufacturer provides a on click stacking function at a deadly expensive price though.

And...lol! and I wonder if the "f ratio" or f stop as in photography plays a role with these cameras in regard to a large portion of the target in "focus". I would imagine but dont know that the f ratio or stop is fixed in these?

Thanks Vlaiv

3 hours ago, Mr Spock said:

Fixed your title - don't know much about microscope sensors though.

Usually sensor resolution depends on pixel size rather than the number of pixels. The smaller and more densely packed they are, the higher the resolution.

Many thanks Michael.

I'm hoping to get more response here than in the microscopy section, mods please feel free to move if needed.

Looking at some USB microscope cameras some have 5MP sensors another 1.3 MP (but more expensive) and I'm wondering about the relationship between the camera sensor pixel count vs actual resolution as seen on a screen? Does the screen itself play a role?

The 5MP is listed at 1600x1200 pixel array and the 1.3MP at 1280x1024 "resolution".

Any help or direction is greatly appreciated, Gerry

Could a mod please make the title sensor not sesnor

The ES 28mm 68 might be a good addition to your line up.

On 10/11/2019 at 09:46, Gervas39 said:

What range of focal lenghts, and eyepieces, do you reccomend? Thanks in advance.

Depends on the targets- the mentioned 28mm would be vg for emission nebula with a filter and your 11mm-12mm good for galaxies and planetary nebs , the latter with and without a filter (OIII,UHC).

On 10/11/2019 at 19:27, Harmony Smurf said:

Curious if anyone has had the opportunity to test the 18mm Tak abbe ortho with glasses on.  The eyepiece isn't common where I live so I can't test before purchasing it.  I wear glasses for astigmatism and also generally observe with a binoviewer. 

 

thanks in advance

The 18mm orthos have about 14mm of eyerelief. I have 2 Tak 18mm orthos that I use with the Denk Binotrons- they are very good. However I find myself reaching for the 25mm and 32mm TV plossls more often than not for the binos/powerswitch. The 32 TV plossl needs the eyeguards IMO.

On 27/10/2019 at 05:26, mdstuart said:

Update on dewing in the shed.

Good solution Mark.

I took a bit different approach that seems to be working well for my shipping container. We painted it a gloss white that I'm told is 90%+ reflective  (any gloss white is apparently).

So far the 24" mirror is within 4 deg f or less of outside and with a temp gradient across its surface of 34.3 deg F on the edges to 35 deg F in the center, +/- .1 deg F. When testing the gradient the mirror was within 2 deg F  of outside the other day. It might track better in the cold than the heat.

Without the white paint the temps with the stock brown were 140F on the surface when 85F outside. With the white paint the surface was ambient + a couple of degrees.

My brother in laws seacan has massive condensation problems, and has installed large vents and fans. Vents can pull in humidity...his sits on wet ground, partially in the shade.

I put the seacan on a crushed rock pad, graded so water flows though it and it also sits on treated 6x6's. The stock sea vents are used. Zero dew so far Mark.

Sorry to ramble but I'm always interested in passive climate control for scope buildings.

Eagerly waiting scope reports and very nice cell btw!

One thing- the process can be iterative - sometimes back to the sec after tweaking the primary etc.

10 hours ago, bond19 said:

Basically, once collimated using the cap, and then collimated using the laser (and lastly doing a final check with the cap). Suddenly everything looks totally out of alignment?

Your 12" f4 is going to need some precise collimation, at least my f4 scope does.

I use a sight tube to center the sec under the focuser and then use an accurate laser to line it up on the primary center marker.

Then a cheshire to line up the primary or Glatters TuBlug/laser.

If it looks like this its good.

7 minutes ago, bond19 said:

I (think) I had the secondary collimated using the colli cap. Then I inserted the laser to align the secondary with the laser dot in the centre of the primaries doughnut. So far all good. Then I collimated the primary using the laser. Again all good. Finally I reinserted the colli cap to check and everything seems massively off 😞

Whats it look like to seems massively off?

The easiest,accurate way to collimate is with a cheshire/sight tube combo tool IMHO.

https://www.firstlightoptics.com/other-collimation-tools/astro-essentials-cheshire-collimating-eyepiece.html

16 minutes ago, bond19 said:

I’ve read the website advice, I’ve watched the YouTube videos. Yet I’m still having major problems collimating my OO UK Dob. I’m using a collimating cap & laser collimator. 
 

Is anyone near or around the Blackpool area who can meet and show me hands on how to correctly collimate my scope? I’m losing the plot!!
 

Thanks 😊 

What is happening exactly?

30 minutes ago, domstar said:

@jetstream I use my 32mm plossl with a UHC. I have an Aero 30mm which shows a larger field but is 2 inch so I can't use my filter. It actually showed up non filtered on Thursday, which surprised me. I wish my Baader plossl had a bigger FOV. The sky is Bortle 4 - east is good for nothing but the Milky Way is clear. 

The Veil gives me a real thrill and is the dso I linger longest on. Maybe not the first thing I'd show a passing stranger, though, especially because it involves fiddling with a filter. Any tips would be greatly appreciated.

Bortle 4- I just cant get on with the bortle scale, SQM or NELM is what I relate to but so is the appearance of the Milky Way, so we'll use that.

Can you see the spur that goes into Cepheus from that location, just above Cass?

Overall I feel that a tight OIII that catches both lines and gives high transmission (high 90%'s) works better in most situations, in particular from rural but not truly dark skies.

Your 30mm-32mm is a nice spot for the low end of eye illumination and you can benefit from more ie a higher fl eyepiece, a 38mm-42mm would be good and work very well with the tight OIII.

Can you easily see Pickerings Wisp in your scope/UHC/32mm?

31 minutes ago, domstar said:

Very true. Had a great night on Thursday looking at the Veil. Amazing but not a great object for a quick look with unadapted eyes. 

Dominic, which fl eyepiece are you using on the Veil with the VG SW 100mm?  filter? one more how dark is the sky do you figure?

I ask because there are "tricks" to get better views of things like this.

45 minutes ago, domstar said:

I just thought it was funny, especially not being able to find the Andromeda Galaxy. It felt like 'Mum, look at me ride my bike'-crash. It's really true that I had about 10 seconds. I wanted to blow minds but actually, what we do is very subtle apart from the moon Jupiter and Saturn. 

Wanting to show a fantastic view of something is a nice idea, sometimes this desire can put extra pressure on, but really we (well me) are only observing for ourselves and if someone else likes it great. A neighbors grown children from far away expressed honest desire to see my equipment and outdoor obs, which I showed them. Next year they are invited to come over to look up and they are excited!

In truth the only jaw dropped on the ground I care about is mine lol! if someone elses does bonus!

IMHO most people could care less about astronomy and we should adjust our expectations accordingly, unfortunately.

I also could care less what people think about astronomy! I just love to observe.

@domstar no need for negative feelings and congrats for getting out observing!

1 hour ago, Northernlight said:

Hi Iain,

Thanks for the feedback. I'm trying to figure out if I need to replace the focuser for imaging or if I can get away with the stock one and save a bit of money as the price sharp creeps up when you add all the extras.

£819 for scope + £115 for 1/10pv upgrade + £220 for a coma corrector, + £50 for secondary dew heater + £240 for Baader focuser + £35 for focuser base plate + £319 for cats eye collimation kit.

So the scope suddenly doubles from £819 to over £1600

My VX10 has a pretty good focuser but fell apart when obs on the ice. I found the parts, loctited them and alls well. The 200mm f3.8's focuser is a complete piece of junk and is barely working now, its a new design with a unique 1.25" adapter.

1 hour ago, Northernlight said:

My only concern about buying the VX10 would be the customer service if I had a problem with the scope.

My 200mm f3.8's primary didn't fit their own cell 😃 so they siliconed it 🤣 causing massive astigmatism

My VX10 is good.

1 hour ago, John said:

Yes, but OO service attitude could be much better from my personal experience, alas

I wish I could say different because I love my OO 12 inch dob.

This is what I meant 😃

54 minutes ago, Northernlight said:

the guy was quite Arsey with me stating that " it's just better". Not helpful at all.

So their customer service still appears to be poor.

Honesty

1 hour ago, johninderby said:

Because it uses circles instead of a crosshair it is a lot more accurate. You move the drawtube in or out until one of the circles matches the outside edge of the secondary mirror. Rotate and move the mirror up or down until it is a perfect circle. This also takes care off offset adjustment. They do 1.25” and 2” versions. Takes eye of eye placement as well during setup.

https://www.teleskop-express.de/shop/product_info.php/info/p5506_TS-Optics-Concenter-2--Collimation-Eyepiece-for-Newtonian-Telescopes.html

Sounds interesting, I might try one. With the Teletube the end can be extended and the focuser racked so it gives a "circle" edge the same as the sec circle picture sight. This will show the position under the focuser very accurately as well.

How do you find the accuracy of sec alignment to the primary and vice versa using this tool?

1 hour ago, johninderby said:

The Telescope Express Concentre is a pricy but simple device for getting your seconday mirror perfectly set up. I had thought my secondary was perfectly set up but found it wasn’t after using the Concentre. Made me realise how imprecise a Cheshire or colimation cap is for setting up the seconday position.
 

Interstingly found my laser colimator gave much better results after setting up the secondary using the Concentre.

 

How does the Concentre work?