The William Optics GTF 81APO, and some questions surrounding it

[tobblerone]

Hello!

Since this is my first time writing here I thought that a short introduction might be appropriate.

My name is Tobias and i live in a small town in the middle of Sweden, about the same height as Stockholm, giving me some pretty nice night skies in the dark part of the year. I've always been interested in space and everything it contains so a couple of years ago i decided to buy a small newtonian (4,5" I believe) on a EQ1 mount. Of course I'm craving for more so I have been saving up for an upgrade. I have already bought a couple of televue eyepieces, which are awesome btw. So now it's time for me to upgrade the rest.

What I have decided to get is the HEQ5. What I have a harder time with is the telescope. But I'm seriously considering the William Optics GTF 81Apo from teleskop-express.

First of all, I think it's sexy as hell! Would'nt mind having it as a decorative piece in my apartment when I'm not using it. Secondly I'm not looking for a newtonian. Living in a small apartment portability will be very important. And to be able skip the collimation part will be greatly appreciated. So an APO seems the way to go for me.

So to the reasons I'm writing here.. Is it a good piece to buy? I have tried looking for some information but not found much. Anyone here have any knowledge about it and can recommend it?

What I want to do with it is mainly astrophotography with my Canon 60D, if it's not too heavy? What will I be able to capture using that telescope? I want to learn taking good DSOs and I understand the process of taking them (Yes, I have ordered Making every photon count, it hasnt arrived yet though) but will some DSOs be out of my reach with the small apparture? Taking into account possible guiding in the future.

Also, will I be able to do any visual observing at all with the telescope if I would so desire? I would be fine with settling with just lunar and solar observing, mostly curious.

The one thing that I don't like is the "foot" to mount it. Will that be enough for astrophotography or should I buy mount rings instead? I'm assuming the foot can be detached.

Also, as of now I have been taking some photos of the moon using my dslr and a t2 ring mounted to my eyepieces. Is that an inferior way compared to mounting the camera in the telescopes prime focus?

It became quite alot of questions but I greatly appreciate any help I can get. I also hope I got the terms right and that you can understand what I'm asking, not being my native language and new to this and all.

Thanks beforehand

[Capricorn]

Do not have that scope, do have the GT-81 variant.

Should be very good for imaging, however from recollections FLO were not happy with some they received and I think returned a number. If FLO read they may be able to comment. Perhaps email them to ask.

Do TE perform a collimation check and adjustment on scopes?

After the GT-81 there was little noise about the GTF-81's when they appeared.

It should be OK as a visual scope, the flattener is built in so adding a diagonal and eyepiece should be possible. The 80mm scope is a nice size for general use, planetary. lunar and some DSO as well. You will not see the same as a 300mm reflector but you wouldn't expect to.

The foot, it can be removed and a set of good rings would be more stable, getting a set of 80mm rings could be more of a problem. Just about everything seems to start at 90mm.

Prime focus photography would produce a sharper image but a somewhat smaller one on the camera sensor.

What you can image will more depend on the duaration and number of exposures then the aperture, you collect say 4 hours of data then process it. A bigger aperture could simply mean collect 3 hours of data. As winter is coming up, and you are in Sweden so more darker hours, try the classic Orion nebula and the Pleiades as first attempts. So within reason all the DSO's should be available to you to image, you just have to find them and keep them in the centre long enough.

Keep in mind that even well set up and aligned you will not get exposures much above 30 seconds, without a guide scope and camera. However that means additional equipment and weight and also power for the extra bits. The mount needs power also.

Owing to the idea that FLO were not happy with some I would ask if TE will check and perform any adjustment before shipping to you. Other then that just buy it to look at.

By the way: Hello. :rolleyes:

[tobblerone]

Okay, thanks for the answer. I will check with the guys at TS if they can check the scope before shipping. Might get in touch with FLO and see if they have something to say about it aswell.

But about the rings, the description says that the tube diameter is 90 mm so that has to be the size of the rings needed right? And as you say, that isn't hard to find

And yea, the nebula in Orion and the pleiades are probably going to be what I'm pointing a new scope towards

Thanks again!

[Capricorn]

I recall that FLO had orders for quite a few, then there was a post by FLO saying that some orders would be delayed as they had returned some to WO, I think it was for them to be reset/collimated or something. Not even sure FLO said exactly why.

I guess they all came back and were sent to the customers. Do know they are dificult to find and I have seen the advert on TE for them, which I was a little puzzled about as the scope has gone from the FLO site and the Ian King site is 6 months out of date concerning it, WideScreen say they have the older GT-81 but not the newer GTF-81 and WO say the older GT-81 is not available. So I would ask a few questions before getting one, something is a little odd.

If they were in limited supply as the GT-81 was then maybe not many ended up here, which would explain lack of information.

[ollypenrice]

WO scopes are always pretty and sometimes good.

I don't think there would be anything wrong with the foot at that sort of focal length. I use the foot on a ZS66 and I use the clamshell on our Takahashi FSQ85. I don't see a problem. Long focal lengths are a different story.

Olly

[tobblerone]

Thanks for your help. I've mailed TE and they say that they always checks the telescopes in their technical department before selling them to ensure that they are working properly. So I will most likely order this scope in the near future

[Coco]

Seems like there is a short supply of William Optics scopes, strange considering they are not being fan-fared by users on here announcing there new kit purchases, seems the GTF was a dud firework .. shame really as the price seemed reasonable..