zwo spacing

[brrttpaul]

Having just ordered the asi1600 and filterwheel I,m looking at the spacing I need? im sure its 55mm or 56, would I need anything else to acheive this? I have attached a photo of my current set up it has an adjustable spacer so that would do wouldnt it?

[brrttpaul]

no one?

[Merlin66]

I think the ZWO website may give you the answer...

The mini filter wheel is 20mm and the backfocus for the ASI 1600 is 6.5mm, you'll need a minimum of "some" T thread spacers to mount the front of the filter wheel to your set-up.....

I don't know what the spec is on your flatner but most are 55mm backfocus.... So: 55 - 20 -6.5 = 28.5 spacers.

 

[brrttpaul]

Thx for the reply but wouldnt that adjustable one shown in pic do?

[Merlin66]

I can't see the detail of the spacer....if it can be adjusted to 28mm then it should work.

 

[brrttpaul]

Thx it is very much appreciated, I am pretty sure it can be I will check later today and see exactly what the min max is

Cheers

Paul

[DaveS]

Don't forget to allow for the optical thickness of any filters in the train after the flattener. To a first approximation 1/3 of the physical thickness.

[brrttpaul]

will do cheers

[Waldemar]

ASI 1600 has a back focus of 6,5 mm, your flattener/reducer ± 56mm, so ± 49 left for the filterwheel and spacer.  The filterwheel is 20 mm thick, so ± 29 mm spacer is needed.

For the used filters you need to add 1/3 of the thickness to the optical path, so for 3 mm filters you need a 28 mm spacer. An adjustable spacer like Baader's VariLock is absolutely great to experiment with, so you can get the optimum distance.

[iapa]

Watching with interest as I have received the ASI1600 and filter wheel and am using the same field flattener on my Equinox

[iapa]

Just took a look and baader have two varilock 

20-29 mm and

29-46 mm

bummer if 29 is the magic number

[Oddsocks]

3 hours ago, iapa said:

29 is the magic number

As you are starting from scratch with this you can use the 20-29mm Baader Varilock and one 5mm T2 extension ring like this:

http://www.365astronomy.com/T2-5mm-Extension-Tube-5mm-Optical-Length.html

Used together this gives you a 25-34mm adjustment range.

I expect FLO do these too but can't find them easily on their website.

[Waldemar]

If FLO does not, AST will have them:  https://www.astromarket.org/accessoires/adapters/

[brrttpaul]

Just had to cancel my order as I ordered it last week now and there was no sign of it coming so email sent and its not in stock and they couldnt give me a date when it will be, which is no good to me as I need to know a day to make arrangements for delivery. not happy 

[Waldemar]

It freaks me out too, that some retailers (most) just do not tell you whether ordered products are in stock or not.
it would just be common decency to let one know when to expect his order.

[brrttpaul]

Well no idea what happened as I left my wife deal with it in the end, went to work yesterday and she phoned me saying it was all sorted!!. Woke up this morning and this arrived on my doorstep. Happy days!!!!

[brrttpaul]

Well I set it all up including the new computer, everything is up and running, the filterwheel, camera, eqmod so wernt as bad as i expected. The one thing though  I connected the camera to the filter wheel and the only way i could get it on the scope was by taking the varilock extender off. I did this then using sharpcap I was looking at the image and adjusting focus (mountain opposite) I wernt expecting it to focus but it did so is that it then no need for spacers? or am i totally missing something here

[Merlin66]

What about a photo of the set-up you ended up with?

What was the final spacing behind the reducer???

[brrttpaul]

I can sort that but all it is is reducer filterwheel camera and looking at sharpcap i could see a blur I just adjusted the focus out and trees came into focus wernt expecting it like I said, but i will re set it all up later today and try it again and take a photo

[DaveS]

The spacers aren't to do with focus but with the optical correction of the reducer / flattener. If it's too short you'll get radial stars, and if it's too long tangential. something like this:

Ignoring all the rubbish in this image, look at the stars in the corners. I had the spacing too short as it was taken through a 1mm thick Astronomik CLS-CCD for luminance, rather than the 2mm thick ZWO RGB that I had calculated for.

[brrttpaul]

I just learnt that i think, like a kid with a new toy I had to try it out even only for a minute, set it up and focused on the moon took a quick snap and it looked elongated so guessed it was the spacer (or lack of it). Lots of things,  cant see how that varilock reducer went on so going to try and find out what i need

EDIT  just had a look at the varilock that i have and its 29 to 46 mm so i have reduced it right down to 29 and put it on between the filter wheel and the reducer is that ok?

[Merlin66]

Should be a good starting point.....

[Waldemar]

maybe you will need the smaller one and an extra spacer as suggested earlier.
It is always a matter of trial and error. Arithmetic only gives perfect theoretical answers. Real life may be a bit different because of tiny flaws in the used products.
The optimal distance of spacing correctors or reducers is very critical...

[iapa]

On ‎07‎/‎05‎/‎2017 at 22:14, brrttpaul said:

I just learnt that i think, like a kid with a new toy I had to try it out even only for a minute, set it up and focused on the moon took a quick snap and it looked elongated so guessed it was the spacer (or lack of it). Lots of things,  cant see how that varilock reducer went on so going to try and find out what i need

LOL

not just me then. I set mine as soon as I got it to - with no reducers or anything.

Was trying to fix an f5 1000mm reflector (damage to mirror near centre - don't ask )

Managed these, no corrector or spacers, so lots of room to improve. When the rain stops.

Both a 4 x 300s each of LRGB, master dark from 40, master bias from 200.

LED street light west of me about 100'

Ordered the 20-29mm spacer which has arrived - so, will try sorting out later this week. How did you get on with yours?

 

[brrttpaul]

I suppose being boys we just cant help it lol we,ll I done what I wanted to achieve and that was get everything talking with each other, eqmod ,sgpro cdc etc and I even managed to take a few subs and stack and combine them so that was a bonus. It opens up other questions though like "when I set up sgpro and connect my camera the zwo logo comes up with highest dynamic range, unity gain etc (i click on unity gain) but if i wanted to take a load of subs in highest dynamic range how do i change it? do i have to disconnect from sgpro and go back in clicking highest dynamic range?