brenski

thanks, will give that a try

thanks. which is the tension screw?

3 minutes ago, Mandy D said:

Daft question: but, have you checked that the locking screw on the sie of the focuser is not too tight?

hi, Focus Locking Screw is underneath on my Dob - and yes, it's definitely loosened

300p Flextube with sysncan/freedom find. anyone know how to fix a focuser? the focusing knob doesn't engage properly - sometimes it works as it should, but sometimes it doesn't - when it doesn't, moving the focusing knob in either direction doesn't move the barrel at all.

even with a barlow?

tube extended another 3" or so - from its first click position. should this now focus correctly? how much of the extra extn tubing can i now remove?

thanks, will check

Sky-Watcher Flextube 300P 12" SynScan GoTo Collapsible Dobsonian Telescope With Freedom Find

Having trouble with focusing. I can focus with a 15mm 2" eyepiece, but 8mm is a struggle - and only (just about) doable.

As you can see from the 2nd image - i've around ½mile of extension tubing attached to the tube just to be able to focus at 8mm!

Ideally, I'd like to add a 2x barlow so that I can see some nice detail of Jupiter and Saturn. Currently the bands on Jupiter are (just about) visible, but my understanding is that the view should be bigger/clearer. How do i achieve this? Which 2" extn tube is the one to use to be able to focus my 8mm with a 2x barlow?

cheers

1 hour ago, Elp said:

You may have to do the infinity focus adjustment on the lens so you can focus slightly past infinity (loosen the three screws around the focus barrel, change the barrel position then retighten). You'll know when you've done it as your red star halos will disappear and turn to green as you move past the red and into green focus point whereas before the mod your stars are usually haloed red. I had to do it for my 135 and 200mm.

thanks, I'm not really confident enough to "not break things". I may have to find someone in the UK who can do this for me - happy to pay to get it done correctly.

that's brilliant ^ , thanks 

4 minutes ago, Clarkey said:

You can get m42 adaptors for 0.75 to 1.0 pitch. I think I ordered some from fleabay. Also, if you search online you should be able to get the back focus for your lens. If you get a variable adjuster it will give you some wriggle room.

thanks. what is a variable adjuster? is that the depth of the  0.75 to 1.0?

thanks

Hi

Just wondering if I can link my Takumar lens to the Altair 183c for image capture

♦ Altair 183c > Takumar SMC 300mm F/4 [M42]

1. Can it be done? what adapter is required?
2. What about backfocus?

thanks

thanks

41 minutes ago, vlaiv said:

What exactly do you want to achieve with that? What sort of effect?

Stacking is performed in order to enhance features that are repeating in the images.

Meteor trails are transient features and appear on single frame. With normal stacking they will be seriously weakened or even erased (if using sigma clipping).

If you want to achieve similar effect like in star trail images - background sky full with meteor trails - then stack with maximum rather then average function (just align on stars as you normally would) and then use max function.

Alternatively - you can combine two approaches for best effect:

1. Stack one image with sigma reject to get nice background image

2. Stack one image with max method to get all the star trails

3. Combine the two images by stretching first more and second less and again using max method (or some alternative with layers in PS/Gimp)

i think I was hoping for what now appears impossible:

I wanted to stack the Meteors showing the radiant with a starry background. I wasn;t intended to capture any landscape and don;t really want star trails - hence the tracked/stacked idea

Does anyone know of a simple method for stacking Meteor showers that were imaged using a tracked mount?

I can't find a method for this for either DSS or Sequator

Is it possible, if so what would be the workflow?

thanks

just an update to this:

for anyone with similar issues, this was my fix:

1] Lindy 10m active usb extn with 5v connector  https://www.amazon.co.uk/LINDY-10m-Active-Extension-Cable/dp/B00B9G4AZ0?th=1

2] USB Type-A Male to 3.5 x 1.35mm DC 5V 1A Plug Barrel Connector   https://www.amazon.co.uk/gp/product/B08JKQHVFD/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

♦ Connect 1 to PC and camera usb cable

♦ connect 2 to 10m 5v connector and other end to power tank.

So far, so good - having taken 100x captures it appears none have yet been dropped. Next step: try again longer exposures at night!

hi, Nitram.

cable length is important as the location of the imaging camera is >5m from the imaging PC located in our garage.

so the 1.8m basics cable won't do

Hi

the Zwo definitely has a fan, but runs off a separate cable.

I've heard from others that their Altair cameras work with a 10m USB  - so it's a mystery.

Hi Martin

thanks for your reply. it's direct PC to camera (no usb hub). This is the same setup that runs the Zwo and SVBony cameras without issue. The Altair, though is a different outcome.

I'm a bit bemused by this one.

Recently bought a Hypercam 183c [fan cooled] camera from Altair, however the USB lead I'm trying to use cuts out at random intervals.
this is the one i currently use with my Zwo183mc and SVBony 205 without any issue at all
https://www.amazon.co.uk/LINDY-43098-Active-Cable-Type/dp/B07B95S2NP/ref=sr_1_5?keywords=lindy powered usb 3 cable&qid=1690280715&sr=8-5&fbclid=IwAR3wlozee6DQpRT3ecoQPXG661zN4O5UQxRZ2IV-bJ1oBBE0oRjuI4jcTFg

However, the Hypercam is a frustrating story and Altair are suggesting my only way forward is with one of their cables meaning another outlay of £125

https://www.altairastro.com/altair-5m-usb30-optical-cable-for-cmos-cameras-type-ab-12309-p.asp?fbclid=IwAR0DG1cRVY4ntQW-AtijTHCGh-Owclsoghs7niy6tykmftkOa8VJbnZH3h8

why are Altair cameras different with regard to cable compatibility? Anyone know a way to get the Lindy cable working?

If not, does anyone know of a cheaper-priced cable that does work with the 183?

cheers

Looking to see if it's possible to connect a Zwo ASI585mc to a Takumar 200mm F/4 (M42 thread)

At present I've used a combination of the various connectors I have and infinity is nowhere near correct. Looks like a backfocus issue.

Has anybody done this successfully using the 2" ring connector?
if so, what connector/spacer did you use? how did you do it

no definitely not.

the whole thing is going back to seller via ebay returns.

thanks anyway