FOT with Starizona Apex ED reducer

FOT(Founder Optics Telescope) widely-separated super triplet is the great optics. But the quality reducer is not currently available. Starizona’s 5-element ED reducer intrigued me a lot. So I made a quick test last night before the cloud came in.

FOT 106 with FOT’s 1.0x flattener and Starizona 0.65x super reducer

As expected, the result looks very good. FOT 106 is originally F6. So 0.65x reducer takes down to F3.9!! See at

Taken with Canon RP in 1.6x crop-mode.

0.65x reducer is so sensitive to the back focus distance like BORG super reducers. So I will continue to test and figure out the best possible distance for FOT 106 and FOT 86 respectively. I will prepare the optimized space rings as Hutech packages. Unfortunately FOT’s 1st shipment has been displayed. I’m expecting this March.

In my personal quality standard, I don’t mind using with full frame sensor although it is not the Starizona’s recommendation. There are some distortion at each corner. But star shapes don’t look bad to me at all.

I hope I might be able to more fine-tune by adjusting the distance. Only concern is the illumination curve. It was taken under the nearly full moon last night. So it might be more exaggerated. Actually Apex’s lens size itself seems not to be large enough for full frame. Let me test without the moon light anyway. If you are confident you can take the quality flat, it might be OK. At least I can say Starizona Apex reducer is well designed!! Great product, highly recommended if you are looking for high quality reducer and don’t need covering the full frame.

2- Since I got the wonderful ASI2600MC, I decided to use a cooled 6D for the wide-field. Basically no need a guide scope. But I’m curious how the dithered imaging makes the result better. This was what I didn’t try out yet.

Cooled 6D with Sigma 20mm/F1.4 Art.

Thanks to IDAS. Fortunately IDAS NBZ filter allows to use with this kind of fast optics as well. I know this Sigma 20mm performs best at F2.2. More stopped down, worse. So I need the well-designed filter like IDAS NBZ without losing the emission signal.

I shouldn’t miss the chance before the galaxy sky will be coming up. It is almost there.

~ by tedishikawa on January 27, 2021.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

<span>%d</span> bloggers like this: