Help deciding between two scopes please

[HughP]

The decision process on equipment has nearly been made but it is a choice between two scopes.

1) Skywatcher Evostar 80 ED Pro

2) Skywatcher Evostar 100 ED Pro c/w free offer of a field flattener

    Both using the HEQ5 Skyscan mount.

The price between the two set ups is only about £10

My thinking behind the ED 100 with FF is that it would reduce the focal length to about 700 and the f stop to f7 bring it to a similar spec to the 80.

With the 80 I would have to buy a FF (extra £150 and the focal length would then reduce to about 500 but with the benefit of a faster f-stop.

Am I missing something in my thinking?  Obviously from my choice of scope I would be limited to what I can do, but you have to start somewhere, Messier objects perhaps.

I aim to start with a DSLR then move on to CCD.

I must admit I did not expect any thing, but the image below gained the wife's approval.

Look forward to some your views.

Regards

HughP

[JR1987]

I would go for the 80. As many will tell you here.. f ratio is so important.. unless you live in hawaii and have clear skies every night.

every f number you increase, you double the amount of time it takes to gather the same data. (I should note I dont have personal experience of this but experienced imagers on here are very clear about this) 

[Apharov]

The effect on data gathering speed is not that drastic with the higher F ratios: a difference of sqrt(2) in F ratio multiplier results in a double the speed difference. https://en.wikipedia.org/wiki/F-number

[Mr Spock]

The problem isn't one of speed or f ratio, it's all about what focal length you can accurately track with an HEQ5. It takes a lot of skill and patience to image with longer focal lengths, and a better mount.

The 80ED is an ideal maximum for an HEQ5.

[Apharov]

The problem isn't one of speed or f ratio, it's all about what focal length you can accurately track with an HEQ5. It takes a lot of skill and patience to image with longer focal lengths, and a better mount.

The 80ED is an ideal maximum for an HEQ5.

This sounds a bit too extreme in my opinion. Many (many!) people have had great success with 130PDS (650mm FL) and HEQ5, and in non-windy conditions even the relatively huge 200PDS (1000mm FL) is within the capacity of HEQ5. 80ED is certainly easy, but certainly not the perfectly usable maximum for HEQ5.

[HughP]

Thanks all for the advice, so the 80 it is.

Now for a bit of research into the mount. My original thought was to go for the HEQ5 but was advised that it is a bit on the heavy side if transporting to remote sites etc and the EQ5 would be the better option.

I will check on the specs and see what the difference is, you can never have a good enough mount and the HEQ5 will allow for a bit of future proofing.

It is good I have the wife on side she will not mind the extra for the higher spec mount!

Thanks 

HughP

[JR1987]

HEQ5 is the way to go id say. It is generally regarded as the minimum spec for imaging (this is just peoples opinions however, theres far too many variables to make

a real statement) But Ive seen great images taken on an EQ5. 

The EQ5 is probably fine for your light 80, However what I will say is one day you might want to add something a bit bigger to your arsenal.. Perhaps an 8 inch newtonian for those smaller galaxies and what not, and thats when you might come into problems with the eq5.

[steviemac500]

I have a 200P on an EQ5 with synscan GOTO. I image with a Canon 1000d and a ZWO ASI120 through the finderscope and I have managed 10 minute guided subs with no weight issues. Yes its probably on the edge of limits but it's workable. The extra weight of the HEQ5 would put me off moving in and out indoors.

[Owmuchonomy]

I would urge that the priority decision for you is the mount.  You can never be over-mounted for AP.  Personal experience has taught me that the HEQ5 Pro is the benchmark starting point.  I owned one for 7 years and when nurtured it is quite capable.  i used it easily up to a FL of 715mm and also at 1350mm, which wasn't so easy.  If i was choosing a scope again (and I will be doing so in the summer) I would decide what I want to image and work backwards to sort out the FL range I needed.  Steviemac is right though, its not lightweight.

[steppenwolf]

Now for a bit of research into the mount. My original thought was to go for the HEQ5 but was advised that it is a bit on the heavy side if transporting to remote sites etc and the EQ5 would be the better option.

Noooooooooooo!! Stick to the HEQ5 - for astrophotography, the mount is the most important component, the EQ5 has little in common with the HEQ5! Don't falter on this choice ......

Oh, another + from me for the 80mm version of the refractor.

[Mr Spock]

Don't skimp on the mount. The HEQ5 is fine for an 80mm and isn't that heavy.

[HughP]

Well it seems that it will be the 80ED and the HEQ5.

Thanks for all the input. After taking a few shots with a standard DSLR and a 500mm lens I am amazed and what can be seen. Takes me back to my school days and that first view of Saturn, WOW never forgotten.

Thanks all.

[ollypenrice]

The HEQ5 could happily image with the 100mm but the 80mm with reducer-flattener would be a better idea. It's faster and, in my view, you enter a bit of a 'no man's land' in the middle focal lengths, especially with the smaller chips, when it comes to target choice. Many of the finest objects are very large and ask for a short FL. A mid focal length can be a disadvantage here without getting you into small galaxy territory. For these you need a long FL and mount capable of guiding it.

The only way to beat an ED80 and an HEQ5 is to spend a lot of money.

Olly

[HughP]

Olly, that seems to be the views from most of the forum. The HEQ5 is what I would like but I have a concern of the weight for transportation. Next step is to go see one for myself.

HughP

[HughP]

Noooooooooooo!! Stick to the HEQ5 - for astrophotography, the mount is the most important component, the EQ5 has little in common with the HEQ5! Don't falter on this choice ......

Oh, another + from me for the 80mm version of the refractor.

Thanks Steve, just ordered a copy of the book - direct.

HughP

[ollypenrice]

For transporting by car I think you'll find the HEQ5 perfectly OK but having a look in the flesh is the only way to be sure.

If you find it too much then I'd re-think your imaging from scratch because the HEQ5 would be my personal minimum for focal lengths in the 500mm region. For somethjing more portable I'd look at an Astrotrac and maybe a Canon 200L prime lens (readily available second hand.)

Olly

[HughP]

Olly, totaly agree with your comments, going to see a mount is my next move. I had considered an Sw Star Adventuer, with my D750 + 500mm but  it would still require a good mount. My Manffrotto 55 is fine for normal photography but not astro!

HughP

[ianaiken]

I started with a 100ed and heq5.  It was a great all rounder scope but master of nothing.  It had a very nice pixel scale amf the detail was great.  It also gave nice views visually.  Bit it was slow for imaging in comparison to an 80ed (which I've also had).  As has already been stated go wide as a lot of targets are big.   So the 80ed on the heq5 is ideal.   I would recommend a finder guider too so you can guide with ease, plus it weighs nothing. And you could use that with a Canon and lens if you went that route.  Once you've mastered that you can then get something for galaxies :-)

I've currently got a 71mm refractor for nebula and a reduced 9.25 for galaxies (and planetary plus visual).

[DaveS]

I would definately go with the 80 pluss FR. F ratio is too importent with a DSLR to sacrifice it to a bit more apperture or FL. I would also ignore the free offer unless it was something I really *needed*.