Ok so whilst leaving subjects behind......

[Stu Wilson]

I thought ok this is probably the last time ill get to image this subject also until next year i thought id grab a few subs and stack and see what happens, bearing in mind this is just after full moon.

This is a grab of 10 x 8 min subs with darks and bias frames.

moon spoiling everything, carlisle in very poluted skies.

imaged through my new ts optics photon f4 with altair quadband filter, superflat coma corrector, and QHY8L as imager with usual NEQ6PRO mount and Orion starshoot autoguider.

Quite pleased to say the least.

 

Clear Skies

 

Stu.

[Clarkey]

You need to move to Penrith for the clear skies and sunshine😉

The delights of F4 imaging. That detail would take me a few hours......

[Stu Wilson]

34 minutes ago, Clarkey said:

You need to move to Penrith for the clear skies and sunshine😉

The delights of F4 imaging. That detail would take me a few hours......

I'm impressed with the difference from f5 to f4 also.

Penrith probably does have some good views 🙂

[scotty38]

That's a great image, off to google the f4 photon to work out why my GT81 images of this subject are nothing in comparison....

[Stu Wilson]

On 01/03/2021 at 17:40, scotty38 said:

That's a great image, off to google the f4 photon to work out why my GT81 images of this subject are nothing in comparison....

Did you find anything out?

[scotty38]

Only that it's 600mm vs my 382mm and f4 vs my f5 so I assumed you cropped in a bit as I have an aps-c sized camera too. Regardless it's a great image that I'd be happy with.

[Stu Wilson]

6 hours ago, scotty38 said:

Only that it's 600mm vs my 382mm and f4 vs my f5 so I assumed you cropped in a bit as I have an aps-c sized camera too. Regardless it's a great image that I'd be happy with.

It's 800mm at f4 and yeah cropped but not hugely. 

Great ota so far though. I'm very pleased with the results I've managed so far. Looking forward to some galaxy imaging etc. Be nice to get to a really dark sky site. Very light polluted round here. Car lights flashing past very often too adds to the frustration.

 

Stu

[Clarkey]

How do you find collimating the F4? I have an F5 newt which is relatively easy, but I am lead to believe the F4's are much more tricky to get right? Having said that, I need to collimate my 8" RC which I am dreading😬

[Stu Wilson]

I took alot of advice from Alicant and Olly Penrice on here and as soon as the ota arrived I did some modifications. Mainly being 6 heavy duty springs instead of the jokes that are supplied I countersunk the three adjusting screw holes and added a kinda cone fit onto my modified bolts which stops alot of movement.

Collimation you gotta check every time to be sure but it either doesn't move or very slightly so 1 minute every time.

If I used out of the box without the pre advice of these guys I'd be sorry I'd bought it because you'd struggle like hell but I'm absolutely delighted with it.

🙂

 

Stu

[Macavity]

In theory (IIRC!) the "Sweet spot" size goes as the CUBE of f-number.
So an f/5 scope is about "twice as easy" to collimate as an f/4 one. 😉

You will have to check, but we are talking a couple of [mm] for f/4.
I reckoned the different "slop" between camera / collimator in the
focusser etc. must approach those sort of levels, so, "best efforts"? 🥳

[Stu Wilson]

The photon has an excellent solid dual speed focuser on so as long as you take a min to check everything is in place it seems great.

[Clarkey]

I think I saw some of the advice from Olly and Alicante - for some reason I thought this was for the SW Quattro. I think in a while I will be really looking at one of these when finance and financial manager (wife) approves. I quite like the idea of the Mn190 but the weight puts me off as I have to set up each night. This would be slightly easier to cart around.

[scotty38]

1 hour ago, Stu Wilson said:

It's 800mm at f4 and yeah cropped but not hugely. 

Great ota so far though. I'm very pleased with the results I've managed so far. Looking forward to some galaxy imaging etc. Be nice to get to a really dark sky site. Very light polluted round here. Car lights flashing past very often too adds to the frustration.

 

Stu

Ah ok read it as 600 so 800 makes it over twice my fl so explains a lot more too. Thanks for the info.

[Stu Wilson]

18 minutes ago, Clarkey said:

I think I saw some of the advice from Olly and Alicante - for some reason I thought this was for the SW Quattro. I think in a while I will be really looking at one of these when finance and financial manager (wife) approves. I quite like the idea of the Mn190 but the weight puts me off as I have to set up each night. This would be slightly easier to cart around.

I was going for Quattro but as there doesn't seem to be anything in UK for last 5 months got pointed to TS Optics version which apparently has better focuser and optics  etc but not certain parts mentioned above. 

So far highly recommended 👌

[alacant]

16 hours ago, Clarkey said:

F4's are much more tricky

Hi

There's a lot of negative hype written about this, usually sourced from old posts when f4s were first mass produced with their hopeless mirror support, inadequate metal tubes and rubbish focusers.

I'm certain early adopters all those years ago did indeed suffer, but it's 2021, the issues have been addressed and as @Stu Wilsonmentions, the only essential modification needed for his GSO was replacement springs for the main mirror. I am at a loss as to why the OEMs can't address this simple upgrade. Proper ONTC grade springs cost just €2.30. For a pack of ten.

Cheers and HTH

 

Edited March 5, 2021 by alacant

[alacant]

On 01/03/2021 at 18:40, scotty38 said:

my GT81 images

Hi

You may find that you need significantly longer than the OP's 80 minutes to get comparable detail.

Cheers

 

 

Edited March 4, 2021 by alacant