david_taurus83

I've had a go at this in Photoshop as well and I have to say, I've never stretched an image so much and not reveal anything! I've brought it into Pixinsight and the background level hardly changes even if I hover the cursor over where there should be nebulosity. What camera did you use? 1 minute subs and 3 hours worth should easily bring it out. Its a very bright target.

It should be saving as a fits file coming from a ZWO camera. My Canon saves cr2 files but are debayered and stretched only for the preview window within NINA.

Whats your LP like? I struggled with a newt when I started. I noticed one night that a strange gradient started appearing on my subs. Turned out to be the bathroom light was switched on by one of the kids and even though the scope wasn't pointed directly (more like 45°) in that direction, the extra light still managed to find its way into the tube. I get the same effect now if one of the streetlamps manages to illuminate the inside of the dew shield on my refractor.

A dew sheild may help to keep stray light out on the 200P.

It doesn't look too bad on the 2600. Full frame is another matter. Did you get it for the Nikon? The spot diagram definitely doesn't show pin point stars at 20mm from centre though.

What reducer did you get with it Adam?

1 hour ago, vlaiv said:

It does eat into violet part of spectrum a bit - so might be part of explanation

To be fair, I wouldn't even consider imaging in broadband or L without some sort of IR/UV cut. The IDAS works well enough from my back garden but if I was to go to a very dark site I would still probably use my clear IR/UV cut filter as well.

11 minutes ago, vlaiv said:

Indeed - I was surprised as well to see that level of CA as well.

I do know that some images taken with ED80 also show slight CA halo and it is also FPL-53 and smaller objective lens and slower than 102 F/7 scope.

I do wonder if filters have something to do with that? I know that proper filters can remove CA blur even with not so well corrected scopes - that is why there are Astronomik L2 and L3 filters.

I've always used an IDAS D2 LP filter so it prob adds a decent IR/UV cut into the equation. Havent tried the DSLR on the 80EDR yet either.

13 minutes ago, TareqPhoto said:

Ok, what do you think about a doublet with reducer to give me about 280mm-320mm and using a mono camera with only Ha filter or only Lum filter?

And what about a triplet with FPL-53 and massive reducer and APS-C color camera?

If shooting mono then a doublet should be fine as your shooting individual channels so you have control from the outset with focusing for each filter and in post processing with regards to control of star sizes. Obviously, if it your having doubts, go for a triplet as they will have better corrected optics.

1 minute ago, TareqPhoto said:

What are you trying to tell me?!!!

That a good FPL53 doublet shouldn't produce blue bloating on stars like the image @vlaiv  has posted.

I used the Altair 102 EDR which is their version of the TS FPL53 doublet. I never seen any of the blue bloat that vlaiv is referring to. Twas a very nice scope and it prompted me to buy their 80EDR doublet as a general purpose imaging scope when I got back into mono. The images below were taken with the 102EDR and my Canon 6D.

I seen a Star Adventurer advertised for something like £500 a few weeks ago!🤯

4 hours ago, MKHACHFE said:

Do you have a link to those? Or a model/name?

 

Cheers

https://www.amazon.co.uk/dp/B0768RS2SB/ref=cm_sw_r_cp_apa_fabc_idreGb2Y8BPBR

The graph indicates that the guide star is off centre slightly on the Dec axis but the corrections are keeping it in place. What you don't want is it bouncing back and forth. Some mounts have excessive backlash and its recommended to guide Dec in one direction only, which would show a similar graph to yours. As you say though, stars are round so that's what matters. Might be worth checking balance and polar alignment next time out.

Can't you return the batteries to Amazon?

I bought 2 cheap ones for my old 600D and they were fine. Bought the same brand again for my 6D and also fine, in fact they probably last longer than the single genuine Canon battery I have.

1 hour ago, vineyard said:

 

FLO are showing the ASI 178MM at GBP346, and Altair Astro are showing the GPCAM3 178M at GBP299+change?

@Robindonne yes that's part of what I'm trying to get a sense of from more experienced folks, esp for lunar/solar.

Stay safe all

I was gonna say the ASI is USB3 but just checked and so is the Altair. But then all the Altair cameras tend to be cheaper. The new 26C is a good £200 lower than the ZWO and QHY variants.

Altair offer fan cooled and tec cooled cameras. Are you sure your not looking at the fan cooled Altair v the ASI183 Pro (tec cooled)?

I used to have the 6AII. The measurements quoted all assume 55mm taken up by the camera from the shoulder. The 6AII has been discontinued for nearly 2 years now so I'm assuming the OP has purchased the 6AIII.

You can get light leak from behind the primary. As Wim says, take the camera off and take your darks. I used the nosepiece that came with the camera, covered it with tin foil and then put the plastic cap over nosepiece. Done my darks during the day with the camera by an open window. No issues.

When you go to the guider tab in NINA, have you reselected PHD2?

18 minutes ago, ratskrad said:

Hi, I just received my WO GT81 IV last week along with the focal reducer. The two numbers to remember are 7.1mm and 60.2 mm. The 7.1mm is the setting for the focal reducer. Spin the pieces until you see the 7mm mark and turn the locking ring. The second number 60.2mm is the distance for the back focus/spacing to the image plane of the camera. There are no instructions for the WO 6AIII but on the webpage for the WO 6AII FR it at least shows the two surfaces that require the 60.2mm spacing. Scroll down and there is a good schematic of the 6AII showing details.  Here are the links to the WO pages for both the 6AIII and the 6AII. Hope this helps.

https://williamoptics.com/products/accessories/barlows-flatteners/2019-all-new-adjustable-flat6aiii-t-mount-not-included

https://williamoptics.com/new-adjustable-flat6a-t-mount-not-included

That's not quite right. The total back focus for the GT81 is 62.1mm. So if you used a DSLR and t ring (44mm + 11mm = 55mm) then you would set the adjustment to 7.1mm to make up the distance to 62.1mm.

ZWO cameras usually come with the spacers to make 55mm as well so in this instance I would recommend setting the the ring to 7.1mm and go from there. You will probably find that you need to adjust either way unless your extremely lucky and have pin point stars corner to corner!

Good choice! I miss mine. Took it to a rare clear night at the local astro club and everyone commented on how sharp the views were. Enjoy!

On 18/01/2021 at 19:02, StuartJPP said:

I see it as a long term hobby. I have no intention on chasing the tech, so will stick with the kit that I have got for as long as it continues to work.

But yes, it does get frustrating occasionally.

I second that though I have to admit I am a sufferer of chronic Gear Acquisition Syndrome or GAS for short!

Its a lifetime hobby for sure. There's plenty of things to image up there, just need to be dedicated and patient. Though it is very frustrating. Last 3 years November through to February has been awful.

I've had 3 SW mounts. EQ5, AZEQ6 and Star Adventurer. Not one of them had an aligned polar scope when I got them. The AZEQ6 was brand new and the polar scope reticle was loose!

How far out was Polaris in the polar scope? I use Sharpcap every time also. Its very good. But perfect polar alignment doesn't mean you will get perfect tracking. Still need to guide to compensate for periodic error etc