Your valued advice wanted on the purchase of a decent AP refractor.

[Belcher]

Looking for some good advice please people. I did post this on the end of another discussion, but it was off-topic where it was.

I am in the market for a good quality refractor suitable for DSO AP but also just as suitable for visual. I think I have pretty much settled on the HEQ5 Pro Synscan mount which is £747. My budget is £1,300. Therefore, I am looking at a spend of up to £550 for the scope. I don't want to end up getting something that I might regret later as the aperture is too small, or the focal length is too long, so it's got to be spot on, and in budget.

I do already own a Meade DSi II which will get me by for now. I appreciate that a decent CCD is going to cost me twice the amount as the scope, so that will have to come later.

Spikey already kindly replied on the other thread with the following

I don't think you will go far wrong with one of these First Light Optics - Skywatcher Equinox 80 APO PRO OTA

or one of these;

First Light Optics - Skywatcher Evostar 80ED DS-Pro Outfit

Both slightly under budget, widely used, supported and rated by owners.

Any other suggestions please? I jumped in head first with a large f/10 Alt-Az SCT and realised after that it was perhaps not the best tool for the job. So I want to do some proper homework on this this time round. Where else am I likely to get great advice but on here

Suggestions ??

Many thanks

[The Viper]

i will be watching this thread with intrest,i have heq5,which i have a 200p and st80 for guiding attached.I am considering the ed80 for imaging as the weight of the 200p has the mount at its limit.Also is a focal reducer required with this scope.

[sologuitarist61]

I appreciate what Spikey has said but you mention not wanting to regret your purchase if the aperture is too small, so I wonder if something larger from the Skywatcher stable might suit you better? You can get a larger aperture with the Skywatcher Evostar 150 OTA for just under £500, though it has quite a long focal length - or there is the Skywatcher Startravel 150 OTA which is a few quid cheaper but is f5 as opposed to the f8 of the other scope.

A great deal really depends on what you want to view

[Carl M]

I appreciate what Spikey has said but you mention not wanting to regret your purchase if the aperture is too small, so I wonder if something larger from the Skywatcher stable might suit you better? You can get a larger aperture with the Skywatcher Evostar 150 OTA for just under £500, though it has quite a long focal length - or there is the Skywatcher Startravel 150 OTA which is a few quid cheaper but is f5 as opposed to the f8 of the other scope.

A great deal really depends on what you want to view

For AP you wouldn't really want to use any of those scopes as they are achromats resulting in chromatic aberration.

An ED80 is the best you will probably get with £550 budget for the scope. If you can get the focal reducer at a later date it will speed the scope up a tad and give a slightly wider field.

[Carl M]

If you are not too worried on the focuser ScopesnSkies are selling the ED80 for £290, you might want to contact them first though to see if they are still in stock. Sounds like a bargain for £290. http://www.scopesnskies.com/prod/telescopes/80mm/sky-watcher/proseries/edrefractors-special.html

[sologuitarist61]

For AP you wouldn't really want to use any of those scopes as they are achromats resulting in chromatic aberration.

An ED80 is the best you will probably get with £550 budget for the scope. If you can get the focal reducer at a later date it will speed the scope up a tad and give a slightly wider field.

What Carl says it quite true:evil6: , but I thought you might need to know need to know what other options you have, even if you then discard them.

[Belcher]

Understood, and thanks for the info so far chaps. £290 is indeed a bargain. So are these really the same thing? The price difference is substantial.

First Light Optics - Skywatcher Evostar 80ED DS-Pro Outfit

and

SnS Evostar ED80 PRO Apochromatic refracter OTA.

[E621Keith]

The SnS version is a reduced accessories model. FLO used to sell those at around £3XX but they don't have stock at the moment. The FLO model comes with a dielectric star diagonal and a dual speed Crayford focuser which the SnS model doesn't have.

SnS made a mistake in their description, the ED80 is a f7.5 not a f6.

A 80mm Apo is still a 80mm, so they would be limited if your tried to see faint fuzzy visually. The differences between a 80mm and 150mm scope is quite obvious. This is not a problem for imaging, because you can compensate with longer exposure, but aperture is the king for visual.

[steppenwolf]

The ED80 is the ideal scope for AP in your budget range but remember to budget for future expenditure for autoguiding as your AP interest develops.

The ED80 is fantastic value for money and highly recommended. Although its aperture does limit its use for visual astronomy with the dimmer objects, it has never stopped me enjoying the view of the night sky!

Its focal length of 600mm will not overtax the mount and when starting out in AP, you really want to make the ride as easy as possible.

[NickK]

Its focal length of 600mm will not overtax the mount and when starting out in AP, you really want to make the ride as easy as possible.

Agreed. From experience 670mm f/6.3 is a nice spot.

I think Olly's rule of sub ~f/7 is a good one - the longer the time required (higher f/number) will be very frustrating too.

[Belcher]

So I guess this slightly larger one that I could stretch to at a push is not as good because its slower? Even though it comes with a focal reducer?

First Light Optics - Skywatcher Evostar 100ED DS-Pro Outfit

Actually, just seen this thread which answers my last question.

http://stargazerslounge.com/discussions-scopes-whole-setups/171827-skywatcher-evostar-100ed-ds-pro-outfit-help.html

[NickK]

Focal ratio = focal length / aperture

A Focal reducer reduces the focal length. This then causes the focal ratio to drop.

It's certainly possible to image at f/12 however it takes four times the exposure time than running at f/6. So 5 minutes becomes 20 minutes.. 3 hours of exposures becomes 12 hours required...

The longer the focal length, the more accurate the mount has to be too. The NEQ6 can easily take a 12Kg load at 600-700mm focal length. At 1300-1400mm focal lengths things start to become far far trickier as the mount is on it's limit unless it's been tuned or setup on a pier.

[laser_jock99]

Focal ratio = focal length / aperture

A Focal reducer reduces the focal length. This then causes the focal ratio to drop.

It's certainly possible to image at f/12 however it takes four times the exposure time than running at f/6. So 5 minutes becomes 20 minutes.. 3 hours of exposures becomes 12 hours required...

The longer the focal length, the more accurate the mount has to be too. The NEQ6 can easily take a 12Kg load at 600-700mm focal length. At 1300-1400mm focal lengths things start to become far far trickier as the mount is on it's limit unless it's been tuned or setup on a pier.

As above - longer focal lengths are really for the more experienced imager, require better mounts, good guiding & fast (expensive) CCD's. I would stick to around the 600mm range for starting out- one of my 'mistakes' was to purchase an ED120/fl900mm refractor. Although a fine scope the long focal length gave a very small field of view even in DSLR sized CCD. I've got a focal reducer for it now but I will be shortly taking delivery of an 80mm/fl600mm apo anyway to fill the gap in my imaging capability. The ED120/fl900mm scope is a keeper as this will be better for when I want to get detailed images.

That said I am currently planing to have I an 10"/F4 fast imaging newtonian by Autumn ready for the next imaging season. This will of course depend on whether I can nail down the guiding issues.........

[Nadeem Shah]

My advice would be get a Evostar 80ED DS Pro Package, if your putting your budget at £550.00 for the scope...Even though the Skywatcher 100ED is a nice scope, but a tad too slow for Astro Imaging...

[Belcher]

Thanks all for the most superb advice. It's saved me jumping before I think again. Looks like my shopping list will consist of the following then:

First Light Optics - Skywatcher HEQ5 PRO Synscan

First Light Optics - Skywatcher Evostar 80ED DS-Pro Outfit

First Light Optics - HitecAstro EQDIR adapter

First Light Optics - SkyTron Power Supply Cable for Skywatcher & Celestron Mounts

That takes me pretty much right up to my budget so I am hoping FLO can do me some sort of "bundle" deal to allow me to afford an extra eyepiece (or two !!)

I want to have the option of controlling the mount from my laptop as I could with my LX200 hence the adaptor. Also, I am assuming it comed with a power lead, but no PSU. And I am guessing the optional lead is just a longer 5 metre one?

Thanks guys

.

[NickK]

The EQ mounts don't come with a power adaptor as standard. The EQDIR module takes it's power from the EQ mount by replacing the handset and then just plug in the USB cable. The Synscan handset possibly the best starting point - then move onto EQDIR/MOD after a little while doing unguided with the synscan handset.

The cable you have linked to is just a 5M cable with a cigar plug on one end. You will need a source of power... I use a battery and a cigar lighter socket thing from halfords that I've hacked to attach to the 12V battery. Others use a 12V power supply.

You may want a couple of 5m USB repeater cables if you want to image in sat in the warm The down side is that your laptop is away from the mount but it works great for winter star parties.

Also I'm not sure, but you may need a field flattener however that can wait until you have things set up and things like polar alignment sorted

[proflight2000]

My penny worth relates to the length of the refractor on the HEQ5. As you know the refractors are long old babies and even on my HEQ5 I had to at times literally break my neck trying to view at certain heights. I'd certainly recommend getting a 16 inch extension tube so as to make life easier, especially when aiming towards the zenith etc, and especially if you want to just put a camera directly into the scope.

[Belcher]

What is the total length of the scope then. I assumed they were not excessively long?

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[Belcher]

Just found that I can get the same scope and mount for the same price, plus a couple of free options, plus the choice of some further add-ons at a reduced cost from here:

http://www.opticstar.com

As much as I love FLO, I would be silly not to . . . . wouldn't I ?

Anyone know if these guys are OK?

Either way, someones getting my money tomorrow

[ollypenrice]

The ED80 is not an exotic choice but it is a good one. Exotic tends to be expensive!

Olly

[Belcher]

OK. The deed is done. Unfortunately, FLO had not replied to my emails, and I rang four times this morning and got voicemail every time saying to email. As I needed to get it ordered ASAP to ensure delivery on the day I was at home, I had no choice but to with Opticstar. Sorry FLO. I did try :-(

[sgazer]

If you want to image then you need a fast focal ratio like f5. F7. 5 is a bit slow. For visual you need 150mm of greater. &for usability you need something of a reasonable size and weight for the heq5 especially if you want to add guiding. Based on experience i would recommend a 150pds.

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[Belcher]

Yep thanks sgazer. All understood, and I also totally agree. However, (a) I didn't want a reflector (been there and fancy and a change!), ( I understand and agree about the f/ but I figured well f/7.5 is still faster than the f/10 I had before and just sold, © I wanted something still quite portable. Oh, and (d) My budget couldn't stretch to the larger frac.

So my thoughts were, invest in a decent mount up front, get the best scope I can get for the remainder of my budget that will perform "OK" for a bit of AP and a bit of visual, and start saving for a faster, hopefully bigger, scope that the mount will handle. The smaller 80mm in the future could then perhaps serve me as a future guide scope.

So I think I did OK

Cheers bud.

[daz]

I have an ED80 (older version)

You'll have to prise it out of my cold dead hands!!

It's great, versatile instrument!

[sgazer]

no worries, you're definitely getting some decent kit together. I really liked the HEQ5, strong and accurate, but not too big to move around. I still have my Celestron C80-ED, which is pretty much the same as the Skywatcher 80-ED, both have killer optics and I can understand the switch from a reflector, no messing around with collimation and always wondering whether it's right or not!

Just with regards to the size of a reflector, the 150pds is pretty compact and I found it ideal for the HEQ5, wouldn't really want to go any bigger, especially with a quide scope on there too. As you probably know already, most of the reflectors are f5 anyway, so all of equal 'brightness' on the imaging sensor, it's basically the focal length that's getting longer with the bigger scopes, which just makes imaging more difficult (needs better tracking and stronger mount).

I had a C8 SCT too, not too bad for imaging with a f6.3 reducer, very nice scope in fact.

ps, hope I didn't sound pushy in my last post, I was typing on my phone so could only manage a few basic sentences!!