William Optics RedCat 51 APO

[Ags]

Is there any way this could give a straight through correct image view with a 32mm plossl?

[Chris]

36 minutes ago, barkis said:

This little fellow is destined for a bright future.    I know I am not the best placed to make this assumption, I'm acting on pure instinct.   The wife and I have crossed swords on my interest, but I will wear her down ?.

Ron.

 

Go on Ron, you can do it  You only live once!

[RayD]

6 hours ago, Demonperformer said:

Watched the video and it looks like a clever piece of kit. I'm not sure I like the helical focusser, but I guess as it doubles as a TP lens it makes sense.

I thought exactly the same thing, and wondered how easy it will be to add a modified auto-focus kit to it.  However, I then thought about the benefit of no focuser draw tube sag and it made a bit of sense as far as imaging goes.

Edited February 9, 2019 by RayD

[Chris]

4 minutes ago, RayD said:

I thought exactly the same thing, and wondered how easy it will be to add a modified auto-focus kit to it.  However, I then thought about the benefit of no focus draw tube sag and it made a bit of sense as far as imaging goes.

I didn't know you had a YT channel Ray, I've off course subbed, That CEM120 is a beast!

As for the helical focuser on the 'Cat', if done right I think it could actually feel better than a single speed crayford fro example. 

Edited February 9, 2019 by Lockie

[RayD]

As a follow on to Steve's post, I am more than happy to run any tests or checks that people want, and include this in my review video.  Feel free to post here or PM me with any specific test that you would like, or certain dimensions etc. (I do tend to show these anyway).

I current aim to run tests with the following:

Atik 460 - ICX694

Atik Horizon - MN34230 (4/3" CMOS)

Atik 16200 - KAF16200 (APS-H)

Canon EOS 450D (APS-C)

I will also try to get some tests using a full frame sensor but, as Steve notes, I personally think it may be a little optimistic to expect this to cover this with a flat and well illuminated image circle but, who knows, we'll give it a go. 

Edited February 9, 2019 by RayD

[wxsatuser]

If you do get time or a chance would be interested in a full frame test.

 

[RayD]

7 minutes ago, Lockie said:

I didn't know you had a YT channel Ray, I've off course subbed, That CEM120 is a beast!

As for the helical focuser on the 'Cat', if done right I think it could actually feel better than a single speed crayford fro example. 

Thanks Chris, much appreciated.  

Yes the CEM120 is certainly a lump!!  I'm doing a long-term series of videos on that, so new videos will be going up pretty regularly on that one.

I agree, I think the helical could be a boon, certainly compared to a Crayford.  I think when you handle the OTA you can see why they have gone this route as it provides for a super compact instrument.

I'm quite excited about testing it and thank @FLO for the opportunity to do so.

[RayD]

1 minute ago, wxsatuser said:

If you do get time or a chance would be interested in a full frame test.

 

Definitely, Mike.  In fact I think I will probably do that first as I genuinely think that is what most people are going to be interested in. 

[wxsatuser]

[happy-kat]

Diagonal use tests please with a:

bog standard one

Erect image one

A posh dielielectric one

[Davey-T]

1 minute ago, happy-kat said:

Diagonal use tests please with a:

bog standard one

Erect image one

A posh dielielectric one

I doubt  if there'll be a choice other than the dedicated one, be interesting to see if it is indeed erect image, you'd think so if it's touted as a spotting scope.

Dave

[RayD]

5 minutes ago, happy-kat said:

Diagonal use tests please with a:

bog standard one

Erect image one

A posh dielielectric one

My initial thoughts are I think this is going to need the short WO screw fit one.  From what I could see it doesn't come with a compression fitting, only the M48 screw back on the rotator.

I'll definitely try everything I can to fit one, and have more adaptors than an adaptor factory so I reckon if it can be fitted, then I will make it fit.

Edited February 9, 2019 by RayD

[R26 oldtimer]

6 hours ago, Demonperformer said:

Watched the video and it looks like a clever piece of kit. I'm not sure I like the helical focusser, but I guess as it doubles as a TP lens it makes sense.

 

31 minutes ago, RayD said:

I thought exactly the same thing, and wondered how easy it will be to add a modified auto-focus kit to it.  However, I then thought about the benefit of no focuser draw tube sag and it made a bit of sense as far as imaging goes.

Oops!! That seems to be that scopes Achilles heel, that will kill it for astrophoto. I think no one will fiddle with 3d printed solutions and stepers to focus a £750 50mm scope.

[Alien 13]

8 minutes ago, RayD said:

My initial thoughts are I think this is going to need the short WO screw fit one.  From what I could see it doesn't come with a compression fitting, only the M48 screw back on the rotator.

I'll definitely try everything I can to fit one, and have more adaptors than an adaptor factory so I reckon if it can be fitted, then I will make it fit.

Looking at one of the videos it seems to suggest that the whole back end comes off including the rotator (not the focusser) which should give more back focus for a diagonal but looks like it needs to be special ...

Alan

[Alien 13]

8 minutes ago, R26 oldtimer said:

 

Oops!! That seems to be that scopes Achilles heel, that will kill it for astrophoto. I think no one will fiddle with 3d printed solutions and stepers to focus a £750 50mm scope.

I cant see that matters, the scope will probably spend most of its time on portable rigs like the SA and most likely with a DSLR or simple CMOS camera set up for hands on AP.

Alan

[RayD]

19 minutes ago, R26 oldtimer said:

 

Oops!! That seems to be that scopes Achilles heel, that will kill it for astrophoto. I think no one will fiddle with 3d printed solutions and stepers to focus a £750 50mm scope.

Hmmm  I'm not sure I entirely agree.  For me personally one of the biggest issues with larger sensors is star elongation often caused by sag in the focus tube, particularly when using filter wheels etc.  You can focus manually with the helical focuser, as you do with many Borg refractors, using the built in Bahtinov mask, which isn't a deal breaker, but a non orthogonal image train definitely is.

Time will tell, but I will certain do long imaging runs also to see how temperature affects focus.

I think, as with DSLR's, many people will come up with a cheap and useful 3D printed solution..........GINA!!!!!! (add this to your list please ?)

Edited February 9, 2019 by RayD

[RayD]

1 minute ago, Alien 13 said:

I cant see that matters, the scope will probably spend most of its time on portable rigs like the SA and most likely with a DSLR or simple CMOS camera set up for hands on AP.

Alan

This was my thoughts too, Alan.  I think when you see how compact it is, and the fact that the dovetail also has a standard tripod profile, it seems evident that WO intended for this to be used on a mobile set up, and not in an automated fixed observatory necessarily. 

It may even be that due to the small objective and fully aluminium construction it doesn't need lots of re-focusing anyway?  It may be an idea to spend one night just measuring FWHM levels to see how much this changes with respects to temperature change.

These are all good comments actually as it is helping me compile a list of specific tests to carry out.

[Alien 13]

7 minutes ago, RayD said:

This was my thoughts too, Alan.  I think when you see how compact it is, and the fact that the dovetail also has a standard tripod profile, it seems evident that WO intended for this to be used on a mobile set up, and not in an automated fixed observatory necessarily. 

It may even be that due to the small objective and fully aluminium construction it doesn't need lots of re-focusing anyway?  It may be an idea to spend one night just measuring FWHM levels to see how much this changes with respects to temperature change.

These are all good comments actually as it is helping me compile a list of specific tests to carry out.

Thanks Ray, manual focus camera lenses do fine on portable rigs and provided the focus ring on this one is smooth and without slop etc it will be a winner. 

Alan

P.S. As it will no doubt be cloudy during your testing it would be nice to know how it does perform as a "camera" lens in the daytime.

Alan

Edited February 9, 2019 by Alien 13

[Davey-T]

Any idea on delivery Ray, Cairds 1st / 3rd March , 5th / 7th April ? 

Dave

[RayD]

5 minutes ago, Davey-T said:

Any idea on delivery Ray, Cairds 1st / 3rd March , 5th / 7th April ? 

Dave

Hopefully, Dave, that would be the plan.

I'm not sure when FLO is expecting delivery, but I believe it is fairly soon, so will definitely bring it along to Cairds if it is here for then.  

[happy-kat]

I think we should keep tests appropriate for the product and not set as if testing a high end Tak or £2000 L glass.

[RayD]

1 minute ago, happy-kat said:

I think we should keep tests appropriate for the product and not set as if testing a high end Tak or £2000 L glass.

Very valid and important point. 

[Alien 13]

5 minutes ago, happy-kat said:

I think we should keep tests appropriate for the product and not set as if testing a high end Tak or £2000 L glass.

True but it is supposed to be the worlds sharpest 250 mm lens 

Alan

[R26 oldtimer]

And at the price of the Tak fc60....

 

[RayD]

7 minutes ago, Alien 13 said:

True but it is supposed to be the worlds sharpest 250 mm lens 

Alan

That's true ?

Mind you, if WO fan Trevor is even saying it's a pretty bold statement, then you can bet it's a pretty bold statement!