Focusing issues with Askar 71F and DSLR connection

All you should need is the photographic adapter and the ring that adapts to your DSLR. There isn’t a specific back focus requirement. What you might do is try focusing on something far away during the day. See if you can at least get it close. If you can then on your next night out you should be close enough to go from there. To do this manually you’ll just have to loosen the coupling to the EAF.

I feel your pain but most of use have been crushed many times in this hobby. I used to be 6’5”…

Hadi Zaheer · Mar 19, 2026 at 06:20 AM

Edit: I hadn’t completely read what Tony had written and went and repeated it all 🤦 Apologies!

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Out of curiosity, did you happen to try reaching focus by hand before you attached the EAF? If not, it may be worth trying to remove the EAF and trying to focus on a distant tree or building during the daytime.

If nothing else, it will get you close to where you need to be and then you can reattach the EAF and go from there at night.

If you're still unable to reach focus that may be a good indication that you may need extensions. But like Tony said, you really shouldn't, as the way you have it attached at the moment, it should just work because of the kind of telescope it is.

Hi Hai

I did try focusing during the day and that worked really well with and without EAF. But when I tried to focused the stars only big donuts and I was at the limit of the scope and I was unable to focus. Tried everything for hour, connecting and disconnecting the EAF. I looked up online and it seems I need a tude extension to increase the distance from the focal length point. But not sure which extension would be best. Thanks Cassio

Cassio Pieroni Trevisani · Mar 19, 2026 at 07:39 AM

John Tucker · Mar 19, 2026 at 12:09 AM

My 91F came with two big extension rings. These were needed to reach focus.

If you find yourself so far out of focus you aren’t seeing anything at all, try doing a 1 or even 3 minute exposure. You’ll probably then see some huge out of focus star. Tweek the focuser a couple of turns one direction or the other and take another long exposure. The big circle should get bigger (wrong direction) or smaller (right direction).

Hi John, thank you for your suggestion even when I got the best focus the stars where still very blown (donut like) . I also tried different long exposures to no avail.

Can you post a picture?

Cassio Pieroni Trevisani · Mar 19, 2026, 07:32 AM

Hadi Zaheer · Mar 19, 2026 at 06:20 AM

Edit: I hadn’t completely read what Tony had written and went and repeated it all 🤦 Apologies!

———

Out of curiosity, did you happen to try reaching focus by hand before you attached the EAF? If not, it may be worth trying to remove the EAF and trying to focus on a distant tree or building during the daytime.

If nothing else, it will get you close to where you need to be and then you can reattach the EAF and go from there at night.

If you're still unable to reach focus that may be a good indication that you may need extensions. But like Tony said, you really shouldn't, as the way you have it attached at the moment, it should just work because of the kind of telescope it is.

Hi Hai

I did try focusing during the day and that worked really well with and without EAF. But when I tried to focused the stars only big donuts and I was at the limit of the scope and I was unable to focus. Tried everything for hour, connecting and disconnecting the EAF. I looked up online and it seems I need a tude extension to increase the distance from the focal length point. But not sure which extension would be best. Thanks Cassio

Ah I see! Having had a bit of a read online as well it looks like a 15mm extension tube might be worth trying out (something like this for example). You'll have to make sure it's a M48 female thread and the male thread on it matches the threading on the DSLR adapter. Which DSLR adapter was it that you purchased?