First telescope 6"Dob vs 8"Dob

[Da Vinci]

Hello everyone. 

I have been studying the sky for last six months through my 7x50 Nikon acculon binoculars, and now I wish to buy my first telescope. 

After a LOT of research on the internet I have narrowed it down to two options :  A 6" 1200mm dobsonian and an 8" 1200mm dobsonian. But now I am stuck.

Since I have never owned a telescope I am not sure what to expect from a 6" dob as against an 8" dob. Will I be missing too much if I opt for a 6" dob instead of 8"? Or should I go for a 6" dob and save some money to invest in some eye pieces later? I wish to have a balanced telescope to see some deep sky objects, and occasionally some planets or the moon. I should mention that I intend to drive up to a nearby mountain for my weekend observation sessions. Will it be too much to carry an 8" dob? 

 

[NGC 1502]

Hi and a warm welcome to SGL 👍

If you can afford it I’d get the 8” f6.  The 8” will be better for deep sky and be excellent for the moon and planets. A telescope like that can be a lifetime instrument.

If you’re averagely fit you should have no trouble lifting the 8” base from your car, then place the tube assembly on the mount. When I’m transporting my Dob by car, the mount goes in the boot, the tube fits across the back seat. You can secure the tube using one of the seat belts, or tie it to the headrest supports, then if you have to brake hard, the tube doesn’t get damaged.

Having said all that, the 6” would still be a great scope.

All the best in your astronomy venture!    BTW, I have good friends in Andhra Pradesh, they lived in the UK for a while, we keep in touch when they join our church services on Zoom 🙂

Best wishes from Ed.

[Ricochet]

25 minutes ago, Da Vinci said:

I intend to drive up to a nearby mountain for my weekend observation sessions. Will it be too much to carry an 8" dob? 

When you arrive at the location, how far will you need to carry the telescope from the car? Can it be done safely in more than one trip? (i.e. can you carry the base to the location and then go and get the OTA?) 

If you are only going to observe a short distance from the car so that you can carry the telescope in a couple of trips, or if the ground is flat and even so that you can safely carry in one piece I would definitely go for the 8". If you need to carry the telescope quite far or the ground is uneven and difficult to walk over, a smaller, more transportable telescope is going to be better. 

[Da Vinci]

24 minutes ago, Ricochet said:

When you arrive at the location, how far will you need to carry the telescope from the car? Can it be done safely in more than one trip? (i.e. can you carry the base to the location and then go and get the OTA?) 

If you are only going to observe a short distance from the car so that you can carry the telescope in a couple of trips, or if the ground is flat and even so that you can safely carry in one piece I would definitely go for the 8". If you need to carry the telescope quite far or the ground is uneven and difficult to walk over, a smaller, more transportable telescope is going to be better. 

I could easily do two trips for the OTA and the base, as the location is not that far from car parking. 

 

I have been saving for last 4 months and have saved enough for a 6" f8. Now I can't wait to get my hands on it.  May be after couple of months I could buy some decent EPs as well. If I am going for an 8" f6, I would have to save for couple of months, and I am dying to hold a telescope, sir. 

But I am aslo concerned about the optical performance of 6" f8. Is it good enough for a decent telescope? Is 6" too small an aperture for faint objects?

[bish]

Although there isn"t a massive difference, I would go for the 8". Star clusters will be that little brighter and some galaxies/nebula might be just visible when you might not have picked them up in the 6". Use it for a while then look into eps

[dweller25]

Both scopes are good but It’s worth saving a little longer for the 8” F/6 telescope as it is a better allrounder.

[Ricochet]

8 hours ago, Da Vinci said:

I could easily do two trips for the OTA and the base, as the location is not that far from car parking. 

 

I have been saving for last 4 months and have saved enough for a 6" f8. Now I can't wait to get my hands on it.  May be after couple of months I could buy some decent EPs as well. If I am going for an 8" f6, I would have to save for couple of months, and I am dying to hold a telescope, sir. 

But I am aslo concerned about the optical performance of 6" f8. Is it good enough for a decent telescope? Is 6" too small an aperture for faint objects?

Well then really it is down to how desperate you are to have a telescope now. If you absolutely have to have a telescope now then the 6" is a good choice and will be a good performer. If you can bear to save for a few more months then the 8" will be just a little bit better on DSOs due to the additional apperture and is worth saving for. Of course the 10" is then a little bit better again than the 8" and the same again for a 12" over the 10". You have to draw the line somewhere and where you draw that line is up to you. 

Edited February 26, 2021 by Ricochet
Correcting auto correct

[AlentejoSkies]

I still have and use my 6" f/8, although the 8" f/6 I used to have was noticeably better on the fainter stuff in a side to side comparison. In my case it came down to what I was happy to carry. The 8" was just a touch too bulky and heavy. Only a small difference, but in practice the 6" was and still is my first choice. The 8" primary is under my bed in a box.

Good luck. Take a good look at the details. In my opinion you can't go too far wrong either way. Choose one and use it. A good dob around that size is enough to last anyone some years.

[Wintersun]

The 8" has a collecting area of 50 sq inches as compared to 28 square inches with the 6" one which is quite a difference. 

For transporting gear from the car there are foldup wagons and carts that have large diameter wheels and pull handles. The ones designed for hunters hauling game out of the woods would work well for moving a large scope from the car to the viewing location. Do a search on Amazon for "game cart" and you will find many to choose from. Add a pad and some bungee cords and you are good to go.

[Spile]

One thing to bear in mind in terms of budget is the possibility that you might want to "add to" your collection. I definitely wouldn't consider this yet, but once you have go used to your telescope, you may feel the need to get a Telrad, right angled finder and additional eyepiece(s). These things can add up as I know 😞