70mm moon 495 longpass

[neil phillips]

Another with the SW Capricorn 70mm F12.9 achromatic refractor. A specialist scope that cost me £39 

When you look at the prices of F13 doublets you quickly realize these are good underrated scopes. That perform like a good long focus doublet should. 

I love it

Baarder 495 longpass QHY UV IR cut EQ5 Mount ZWO 178M Camera

50% And Full size  23 degrees elevation

 

Edited November 2, 2021 by neil phillips

[Franklin]

Baader 495 longpass really works well at cutting the CA. Amazing images considering the equipment.👍

[neil phillips]

3 minutes ago, Franklin said:

Baader 495 longpass really works well at cutting the CA. Amazing images considering the equipment.👍

Hi Franklin yes it does. Ive found the UV IR cut And 495 nm filters seem to produce the sharpest images with Achromatic optics. 

Cheers

[Franklin]

The 495 works great for visual with achros too, as long as you can see past the yellow. I used one with a 6" f/8 all the time. I read on the forums how some folk can't stand the yellow, I don't see what the problem with yellow is. You don't hear white light solar observers complaining about a green Sun! The 495 sharpens things right up.

[neil phillips]

10 minutes ago, Franklin said:

The 495 works great for visual with achros too, as long as you can see past the yellow. I used one with a 6" f/8 all the time. I read on the forums how some folk can't stand the yellow, I don't see what the problem with yellow is. You don't hear white light solar observers complaining about a green Sun! The 495 sharpens things right up.

Agreed, by removing the out of focus blue light. It rids the scopes of that smearing effect. At F12.9 theres not a lot here. But the 495 still has a de smearing effect for what little is there. Grey scale still benefits. So no yellow here. But yes get your point

[vlaiv]

You should try Solar Continuum with achromats for the moon, if you have one.

I think that is the best filter for imaging the moon with achromats.

[neil phillips]

1 hour ago, vlaiv said:

You should try Solar Continuum with achromats for the moon, if you have one.

I think that is the best filter for imaging the moon with achromats.

Dont have one but if the light loss is not significant sounds good.

[vlaiv]

1 hour ago, neil phillips said:

Dont have one but if the light loss is not significant sounds good.

I think that light loss is quite strong. It could be considered NB filter.

I think it will be good for achros because it is centered at 540nm. Most achros are optimized for that wavelength so not much spherical. Filter is narrow enough so that CA is not issue at all. I used it visually with 102mm F/5 achro on lunar and view was razor sharp. It has better resolution than say Ha narrowband often used for lunar imaging because of wavelength.

Alternative is to use OIII NB filter. It is also good - at 500nm, again that is zone of good correction, and wavelength gives good resolution but it is more into blue part of spectrum where atmosphere causes more disturbance. Solar Continuum also has wider FWHM - which means that it passes more light.

 

[Trevor N]

4 hours ago, neil phillips said:

Another with the SW Capricorn 70mm F12.9 achromatic refractor. A specialist scope that cost me £39 

When you look at the prices of F13 doublets you quickly realize these are good underrated scopes. That perform like a good long focus doublet should. 

I love it

Baarder 495 longpass QHY UV IR cut EQ5 Mount ZWO 178M Camera

50% And Full size  23 degrees elevation

 

Always amazes me what a small refractor can do. Lots of detail. Trevor 

[neil phillips]

18 minutes ago, vlaiv said:

I think that light loss is quite strong. It could be considered NB filter.

I think it will be good for achros because it is centered at 540nm. Most achros are optimized for that wavelength so not much spherical. Filter is narrow enough so that CA is not issue at all. I used it visually with 102mm F/5 achro on lunar and view was razor sharp. It has better resolution than say Ha narrowband often used for lunar imaging because of wavelength.

Alternative is to use OIII NB filter. It is also good - at 500nm, again that is zone of good correction, and wavelength gives good resolution but it is more into blue part of spectrum where atmosphere causes more disturbance. Solar Continuum also has wider FWHM - which means that it passes more light.

 

Interesting Vlaiv. Larger refractors would benefit the most in situations of strong light loss. Could be worth experimenting with a solar continuum with my bresser 127l. Not yet though presently saving for a new planetary lunar scope

[neil phillips]

5 minutes ago, Trevor N said:

Always amazes me what a small refractor can do. Lots of detail. Trevor 

Especially for the moon Trevor. Planets can be more limited at this size. But for the purpose ive used here, they are useful, and a lot of easy fun

[PXR5]

Very nice captures 👍

I don't see any CA! 

[WestCoastCannuck]

Really nice Neil!    Love to see what these tiny apertures can produce.  :)))

[neil phillips]

6 hours ago, PXR5 said:

Very nice captures 👍

I don't see any CA! 

Its greyscale. So it wouldnt really show. But the fuzz often can. Cheers

[neil phillips]

11 minutes ago, WestCoastCannuck said:

Really nice Neil!    Love to see what these tiny apertures can produce.  :)))

Hi Mike. Have to admit i get a real kick from seeing what a good cheap small scope can do. its kind of satisfying 

Cheers