Show Us Your Dobs

[Stardaze]

13 minutes ago, John said:

Mine is branded Astro Engineering but I think this is more or less the same thing:

https://www.firstlightoptics.com/dew-prevention/astrozap-light-shield-for-dobsonian.html

Where I mostly observe from, up until 11:00 pm or so, I do have lights going on and off and I found that shielding the upper end of the tube kept stray light off the secondary mirror and the end of the focuser tube - makes quite an improvement in contrast when deep sky observing. 

When I take the scope to to darker surroundings I don't use it.

Some folks use an all round light shield which are effective as well. My light issues tend to come from the same direction though hence the partial shield. I can slide it around the tube if needed and it pops on and off easily (velco strap).

 

 

My neighbours security light can be a nuisance!

[Stu]

16 hours ago, John said:

How does the 00 8" F/8 compare with the Mewlon 210 Stu ?

Or is the jury still out on that ?

Need some moe time comparing them John. Despite the similarities they are in some ways complementary. The Dob is good for single targets, just concentrating on the Moon or a planet for instance but is more of a pain to pan around finding different targets. The Tak is very useable on the AZ100 mount for finding more variety.

The dob cools a lot more quickly, and the collimation is very stable; I haven’t adjusted it for ages and it is still spot on. The Mewlon can take a long time to cool if it has been somewhere warm, and whilst the secondary collimation is very solid, I find the primary mirror flop quite frustrating. If you adjust in an upwards direction with the main focus that corrects it, and I then use the FeatherTouch for find adjustments.

Last night the seeing wasn’t so good, but the dob was still showing me the Hadley Rille, although not as clearly as the previous night when the seeing was better. I put the Mewlon out to give that a go, but it needed more time than I had to cool down. The views were soft and there were no hints of the Rille. No surprise really, it needs to be put out to cool an hour ore more before observing then it will have a chance. The dob lives somewhere cool to be fair so has an advantage.

They both split Zeta Herc a while back for me so are both very capable, as I recall the Tak gave the cleaner view of the two back then so is ultimately optically better I think. Less scatter at high power.

[JeremyS]

1 hour ago, Stu said:

Need some moe time comparing them John. Despite the similarities they are in some ways complementary. The Dob is good for single targets, just concentrating on the Moon or a planet for instance but is more of a pain to pan around finding different targets. The Tak is very useable on the AZ100 mount for finding more variety.

The dob cools a lot more quickly, and the collimation is very stable; I haven’t adjusted it for ages and it is still spot on. The Mewlon can take a long time to cool if it has been somewhere warm, and whilst the secondary collimation is very solid, I find the primary mirror flop quite frustrating. If you adjust in an upwards direction with the main focus that corrects it, and I then use the FeatherTouch for find adjustments.

Last night the seeing wasn’t so good, but the dob was still showing me the Hadley Rille, although not as clearly as the previous night when the seeing was better. I put the Mewlon out to give that a go, but it needed more time than I had to cool down. The views were soft and there were no hints of the Rille. No surprise really, it needs to be put out to cool an hour ore more before observing then it will have a chance. The dob lives somewhere cool to be fair so has an advantage.

They both split Zeta Herc a while back for me so are both very capable, as I recall the Tak gave the cleaner view of the two back then so is ultimately optically better I think. Less scatter at high power.

Thanks Stu. I was also looking forward to your thoughts. This is helpful. Hopefully more to come....

[Barry-W-Fenner]

On 03/05/2020 at 11:30, John said:

Mine is branded Astro Engineering but I think this is more or less the same thing:

https://www.firstlightoptics.com/dew-prevention/astrozap-light-shield-for-dobsonian.html

Where I mostly observe from, up until 11:00 pm or so, I do have lights going on and off and I found that shielding the upper end of the tube kept stray light off the secondary mirror and the end of the focuser tube - makes quite an improvement in contrast when deep sky observing. 

When I take the scope to to darker surroundings I don't use it.

Some folks use an all round light shield which are effective as well. My light issues tend to come from the same direction though hence the partial shield. I can slide it around the tube if needed and it pops on and off easily (velco strap).

 

 

I am now considering one of these light shields for the 200p. I really like the contrast gains from the astro zap dew shield, but I am starting to find that at low to medium altitude its weighing the front of the scope down and taking me of target. The only thing putting me off the light shield is the price.

baz

 

[John]

2 hours ago, Barry-W-Fenner said:

I am now considering one of these light shields for the 200p. I really like the contrast gains from the astro zap dew shield, but I am starting to find that at low to medium altitude its weighing the front of the scope down and taking me of target. The only thing putting me off the light shield is the price.

baz

 

You could probably make one from an old foam camping mat and some vecro tape. You could have the design that suits you then.

I've used a cardboard shield before and it did the job. Just didn't look too smart but who cares in the dark !

 

[fiestazetecmk2]

I made mine from a yoga mat.best £2:00  i spent.

[Barry-W-Fenner]

1 hour ago, John said:

You could probably make one from an old foam camping mat and some vecro tape. You could have the design that suits you then.

I've used a cardboard shield before and it did the job. Just didn't look too smart but who cares in the dark !

 

I think that might be the best idea John. I need to get all Blue Peter on it! I am not a huge fan of the shape of the Astro Zap Shield. I would prefer something more half circular like your Astro Essentials shield. I have had a look around but cant seem to find much from them. 

I have some left over flocking, I could cut one from card and line it with the flock, Then attach with tape!

Another little project to get on with in the down time 🙂

 

[Stardaze]

Still getting to know my new purchase but loving her so far. Need to add a handle this week I think but very happy new dob owner to date. The RACI only turned up yesterday, which is a very nice addition. I might add a dew shield to see whether that helps with some stray light, dependent on where it's positioned in the garden. This snap last night was in a new position enabling me to see Lyra from 12.30. I'll be no doubt be building my EP collection in readiness for the winter. Fancy an OO base at some point, but absolutely no rush for that. Thanks to those that have given me some great advice so far..

 

Edited May 16, 2020 by Stardaze

[John]

That's looking a very handsome scope

 

[Stardaze]

14 minutes ago, John said:

That's looking a very handsome scope

 

She’s not bad for a first huh! 😆

Not too big though, as long as my back is sound, she shouldn’t be too much trouble to cart around. 14 and above look just huge, but.. very intrigued just to see what something that big delivers (not practical for me thankfully)

Was looking at the OO site yesterday and the grades of mirrors are really something, not for the light walleted! Which grade of mirror is in yours John?

Edited May 16, 2020 by Stardaze

[johninderby]

Looking good. 👍🏻👍🏻👍🏻

Fitting OO 1/10 PV mirrors to the Bresser would be over £700.00 but would make quite an upgrade although the Bresser mirrors are pretty good though.

 

[Stardaze]

2 hours ago, johninderby said:

Looking good. 👍🏻👍🏻👍🏻

Fitting OO 1/10 PV mirrors to the Bresser would be over £700.00 but would make quite an upgrade although the Bresser mirrors are pretty good though.

 

Don't worry, not about to go that crazy, just curious as to how much better they actually would be for that kind of money. Eyepieces are my next endeavour, going to need a 6/7mm then a 11/12mm, can upgrade gradually if the bug bites...

You did say that the Bresser mirror is as good as anything for the money.Maybe she could have that upgrade for her 5th birthday 😀

[cloudsweeper]

@Stardaze - a fine 'scope indeed!

Here's mine on its homemade platform - makes it easier to view through.

Doug.

[Stardaze]

5 minutes ago, cloudsweeper said:

@Stardaze - a fine 'scope indeed!

Here's mine on its homemade platform - makes it easier to view through.

Doug.

There's a few of here with them then 😀 How long have you had yours? Looks like you've had to DIY your Rigel 👍

[johninderby]

23 minutes ago, Stardaze said:

Don't worry, not about to go that crazy, just curious as to how much better they actually would be for that kind of money. Eyepieces are my next endeavour, going to need a 6/7mm then a 11/12mm, can upgrade gradually if the bug bites...

You did say that the Bresser mirror is as good as anything for the money.Maybe she could have that upgrade for her 5th birthday 😀

On nights of average seeing you wouldn’t see much of an improvement with the OO 1/10 mirrors but when the seeing is good then you would notice the difference.

Had an Skywatcher 150 f/8 newt that I upgraded with OO 1/12 PV .993 Strehl mirror bought second hand on ABS. Shouldn't have sold that scope. Was an amazing performer.

Edited May 16, 2020 by johninderby

[John]

Its the usual thing with optical quality. Most of the time there is little in it but differences start to show when the conditions are good and when you are going for challenging targets.

 

 

[Alan White]

I think we should add to @John this and other comments:

When you are a seasoned observer and have learned to observe then and only then......

Its the usual thing with optical quality.
Most of the time there is little in it but differences start to show when the conditions are good and when you are going for challenging targets.

[Stardaze]

8 minutes ago, johninderby said:

On nights of average seeing you wouldn’t see much of an improvement with the OO 1/10 mirrors but when the seeing is good then you would notice the difference.

I take heart from the fact you’ve had most stuff and settled on the Bresser of late. 

1 minute ago, John said:

Its the usual thing with optical quality. Most of the time there is little in it but differences start to show when the conditions are good and when you are going for challenging targets.

 

 

It’s like most top of the range gear with anything, marginal gains. Mid-range kit normally gives you the biggest step up from starter kits, but the highest end tends to be less noticeable, but marginal for those that either need the very best, or

moneys not a concern. I’m intrigued with TeleVue eyepieces, I can see how quality glass can make a difference, but, it’s all relative. Probably no

point slapping an eyepiece on a scope of the same value.

[Stardaze]

1 minute ago, Alan White said:

I think we should add to @John this and other comments:

When you are a seasoned observer and have learned to observe then and only then......

Its the usual thing with optical quality.
Most of the time there is little in it but differences start to show when the conditions are good and when you are going for challenging targets.

Absolutely this! I do like to warrant the gear I’m using, and it’s good to have things to ‘aspire towards.’ 😀 

[johninderby]

The Law of Diminishing Returns

Making good mirrors isn’t that expensive nowadays but with any improvement costs rise exponently plus it’s a smaller market.

Edited May 16, 2020 by johninderby

[Stardaze]

14 minutes ago, johninderby said:

The Law of Diminishing Returns

Making good mirrors isn’t that expensive nowadays but with any improvement costs rise exponently plus it’s a smaller market.

I’d imagine they have to make very good margins on mirrors. I can only speak of camera lenses, but assume the same of EP’s (they’re essentially similar makeup), but camera manufacturers make their money on lenses with big mark ups. Camera bodies don’t provide much of a return. The only difference with all of this though is that I’d be confident of taking half decent pics with cheap glass, but in this game, the difference could be between seeing something, or not I guess.

Lenses are an investment in photography - they can last you lifetime across many bodies. To some respect, assume the same of EP’s..

[John]

19 minutes ago, Stardaze said:

... I’m intrigued with TeleVue eyepieces....

I caught that bug quite a few years ago and it has cost me dearly

There are other quality brands / ranges around now as well though - Pentax, Nikon, some of the Explore Scientific, some of the APM's, etc, etc.

I believe the profit margins on astro gear are relatively small, at least at the retailer level.

 

[Stardaze]

6 minutes ago, John said:

I caught that bug quite a few years ago and it has cost me dearly

There are other quality brands / ranges around now as well though - Pentax, Nikon, some of the Explore Scientific, some of the APM's, etc, etc.

I believe the profit margins on astro gear are relatively small, at least at the retailer level.

 

Most retailers get the blunt end of the deal. You have to wonder who will survive this current situation. I’d like to think that with pastimes such as Astro, people will continue to seek some escape and solace in this hobby, and others. I do a fair bit of cycling and one of the biggest wheel manufacturers has just gone under.

[JeremyS]

5 minutes ago, Stardaze said:

Most retailers get the blunt end of the deal. You have to wonder who will survive this current situation. I’d like to think that with pastimes such as Astro, people will continue to seek some escape and solace in this hobby, and others. I do a fair bit of cycling and one of the biggest wheel manufacturers has just gone under.

That's a shame as I see one area where sales have been soaring during the pandemic is bicycles.

[Stu1smartcookie]

3 hours ago, cloudsweeper said:

@Stardaze - a fine 'scope indeed!

Here's mine on its homemade platform - makes it easier to view through.

Doug.

Just bought one of these this week , my wife went a bit crazy when she saw the size of the thing but Venus quickly came to my rescue when she saw it  in the eyepiece .. i found a place for the scope in my wardrobe (glad i dont like clothes shopping   )  . Like the platform.. . and literally  love this scope . for its size its quite portable , which is just as well as where i live there is lots of LP .