071 without IR/UV

[alan potts]

What can I expect if I use my .79 reducer without a IR/UV filter in place, I cannot see  a way of using one in the Zwo tube set-up and the reducer is way too big on the scope side (67mm) to get a filter on.

Anyone any ideas how I can keep 55mm backfocus and get a filter in the line, I can get a 1.25 inch filter in but that is way too small for 071 sensor. Surely I cannot be to the only to have this issue.

Alan

[Laurin Dave]

Could you get a 67mm male to female adapter made up with a 2" filter thread in the middle to put before the reducer?

[DaveS]

You could put a Filter Holder in the imaging train. Without a UV / IR cut filter you will get considerable star bloat from uncorrected colour in any refracting telescope, yes even the eye-watering apos.

[david_taurus83]

I had to get a filter drawer Alan for my reducer, same as yours. M48 version, 15mm thick.

https://www.365astronomy.com/ts-optics-filter-quick-changer-for-2-filters-m48x0.75-thread-length-15mm-including-filter-drawer.html

[alan potts]

6 hours ago, david_taurus83 said:

I had to get a filter drawer Alan for my reducer, same as yours. M48 version, 15mm thick.

https://www.365astronomy.com/ts-optics-filter-quick-changer-for-2-filters-m48x0.75-thread-length-15mm-including-filter-drawer.html

David, this would be fine if this business ever replied to an e-mail, I asked 2 questions of them a long time back and got nothing. However the ZWO spacer where this would fit is 16.5mm and that would still leave 1.5mm to fill, shim maybe?

Alan

[alan potts]

I tried about 3 hours last night in damp and frosty weather but nicely clear. I imaged the Soul and part of the Heart (how big is this target).  Not processed yet but the images were poor for other reasons, stretched stars going into the corners.

The spacing for this is quoted at 55mm which according to Zwo you get exactly by putting the spacers together, this works very well with the Hutech flattener which is about perfect as I see it. Maybe this rather larger TS reducer at 360e is not all it's cracked up to be, pleased I didn't pay that for it, it may only be a minor spacing issue but one I don't really understand and best forgotten in my view.

I would soon buy another scope and use the Hutech, which is a very nice piece of equipment that was recommended to me by Steve, one of the Mod team, a man that knows a few things about imaging. 

Alan

[gorann]

I have te same reducer (if it is the 0.79x 3" version from TS) and have been using it on my Esprit 150 with the ASI 071. I also worried about the filter and TS told me that I needed to use a fliterslider as David did. However, I have been trying without a IR/UV filter and I actually do not see much star bloating. My main problem has been spacing. 55mm gave very long stars in the corners, and so did 54 (marginally better). Last session I tried 53 mm and it was better but still not good. I will try 52 mm next time.

[Laurin Dave]

Just now, gorann said:

However, I have been trying without a IR/UV filter and I actually do not see much star bloating.

That Goran, is because it's an Esprit!

[gorann]

2 minutes ago, Laurin Dave said:

That Goran, is because it's an Esprit!

Yes, I was about to say that.....

[alan potts]

15 hours ago, gorann said:

I have te same reducer (if it is the 0.79x 3" version from TS) and have been using it on my Esprit 150 with the ASI 071. I also worried about the filter and TS told me that I needed to use a fliterslider as David did. However, I have been trying without a IR/UV filter and I actually do not see much star bloating. My main problem has been spacing. 55mm gave very long stars in the corners, and so did 54 (marginally better). Last session I tried 53 mm and it was better but still not good. I will try 52 mm next time.

I actually seemed to get different results from this reducer even using 55mm and I am assuming the spacers with the 071 do give me 55mm. When I used my Canon this gave very good results and this too is or should be 55mm. With the scope F/L at 805mm I did wonder if the spacing should be a a little less as with scopes of smaller F/L the figure goes up, I.E.  58mm quoted at 600mm. I did try it without and can't say I saw much different at all but with the moon about my choice of target was a bit washed out.

The trouble with the filter slider in my view is it is just too damn expensive for what it actually is, I think I would rather buy another scope and have something to show for the outlay, as I had some sort of reflection issue with the reducer that I never found an answer to, it just went away.

Alaways fancied a 150mm Espirt, should have got one when my friend and local dealer offered me one for 3500e, I bought an 18 inch Dob instead.

Alan