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Old 07-06-2018, 06:56 AM
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Tak MT reducer - is it a coma corrector???

Hi all,
I have been using my tak MT-160 for a while not with the 0.85x reducer. Even with the correct spacing (56mm) i still have bad coma issues. This raises the question, is it even a coma corrector at all or is it just a reducer?
I hope i don't have to buy a coma corrector (which also means i have to image at f6/1m instead of f5/0.75m)
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Old 07-06-2018, 07:04 AM
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Just to be SURE LOgan, the 56mm is from the rear metal of the reducer (NOT the threads, the surround of the reducer housing) to the SENSOR plane (not to the end of the adaptor).

A photo with your reducer in train would be ideal (of the euipment, not with it lol)

I also recall the state of the reducer as you received it...hardly ex-factory (memories of silicon and a weird plastic or shoddy made aluminium ring come to mind).
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Old 07-06-2018, 07:08 AM
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Hi Lewis, "rear metal of the reducer" what do you mean? I am accounting for the 6.5mm to sensor by the way. pics in next post
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Old 07-06-2018, 07:10 AM
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Old 07-06-2018, 07:11 AM
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The train at the moment which adds to 56mm or so is Reducer > 1mm m54-t2 > 16.5mm spacer > 21mm spacer > 11mm spacer > sensor (6.5mm)
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Old 07-06-2018, 10:18 AM
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Are you accounting for the 4mm of the front T-adaptor as shown in the schematic? (or is this part removeable?) This will make it 10.5mm total just for the cam consideration, leaving you 45.5mm to account for from the T adaptor on the cam to the rear edge of the reducer
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Old 07-06-2018, 10:53 AM
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Not sure about that Lewis but i do know that i had the 56mm with the DSLR and it also had coma issues...
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Old 07-06-2018, 10:58 AM
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Shouldn't you be at school?
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Old 07-06-2018, 11:02 AM
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Sure you don't want a lovely FLAT FIELD VC-200L (and I include the reducer also)...plus an extra set of ultra thin spider vanes...

Direct swap
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Old 07-06-2018, 11:33 AM
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Quote:
Originally Posted by LewisM View Post
Sure you don't want a lovely FLAT FIELD VC-200L (and I include the reducer also)...plus an extra set of ultra thin spider vanes...

Direct swap
f/9? still 6.4 with the reducer
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Old 07-06-2018, 12:02 PM
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You can go DEEP and fairly wide, all built-in FLAT field. Win win....
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Old 07-06-2018, 12:05 PM
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ehhhhh no thanks - would take a lot more than that to convince me to sell
All these posts always end up like this dont they...
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Old 07-06-2018, 12:09 PM
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Of course

Now go fix your spacing.
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Old 07-06-2018, 12:11 PM
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Question still stands - is it even a coma corrector?
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Old 07-06-2018, 12:33 PM
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Quote:
Originally Posted by Lognic04 View Post
Question still stands - is it even a coma corrector?
"The dedicated reducer (f4.8) yields a perfectly flat field even on a 24mm dslr chip." - found that on the web. Tak reducers are traditionally reducer/flatteners. The corrected image circle with the reducer is 36mm - are you larger than that with your ZWO?

Can you show a picture of the inscribed label/data on the reducer please Logan - it may not be the right one
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Old 07-06-2018, 12:40 PM
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micro 4/3 with the zwo actually! I will check the label out when i get home
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Old 07-06-2018, 12:46 PM
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Edit: it says it is for mt-160 looking at an old photo. "for mt-160 reducer f4.8"
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Old 07-06-2018, 12:47 PM
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Also, is the coma equal in each corner? Please do show a good set of photos of the reducer, as well as images taken with it recently.
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Old 07-06-2018, 12:53 PM
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https://drive.google.com/drive/folde...2dSZWxTYlBmaU0 This is the reducer - although currently it is as shown in the photo with the ASI. I will show a pic when i can, and i will also check the coma
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Old 07-06-2018, 03:21 PM
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