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Antares 2" 0.5x Focal Reducer
| Brand | Antares |
| Part Number | FR2 |
| Availability | available |
| Share |
Product Info
Manufacturer Description
Antares' 2" 0.5x focal reducer screws on to any accessory (such as eyepieces, camera adapters, etc.) that accepts standard 2" threaded filters and provides a nominal reduction of 0.5x. Use of this focal reducer effectively halves the focal ratio of your telescope, resulting in a wider field of view and significantly shortened exposure times for astrophotography. For example, use of this reducer will convert an f/10 telescope into an f/5 scope.
The 2-element reducer features fully multi-coated optics in a black-anodized aluminum filter cell. This focal reducer will work well for visual use too when coupled with the right kind of eyepieces and telescopes (it is not recommended for very fast scopes or very wide angle eyepieces for visual applications). This new, improved version also features a 2" female thread so you can screw/stack additional 2" filters on to this reducer.
The actual reduction will vary a little over or under 0.5x depending on exactly where the focal reducer is placed in the optical path. The focal length specification of this reducer is 158mm. Hence, the "working distance" of this specific reducer is 79mm, i.e., this reducer will provide a reduction of 0.5x when the center of its lens assembly is placed 79mm from the focal plane of the eyepiece or imaging device. Move the focal reducer closer to the eyepiece/camera and its reduction factor will increase. Move it away and the reduction provided will decrease.
By using additional spacers or extension tubes (sold separately), you can vary the amount of reduction you obtain with this reducer as follows:
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Extra Spacer Length
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Nominal Reduction Provided
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0" / 0mm
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0.50x
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0.25" / 6.4mm
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0.46x
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0.5" / 12.7mm
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0.42x
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0.75" / 19.1mm
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0.38x
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1" / 25.4mm
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0.34x
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Note that the use of any optical element like barlows and focal reducers changes the focus point of your telescope, requiring additional in-focus or out-focus travel. The exact amount of focus travel required will depend on the optics and mechanics of your specific set-up (telescope, diagonal (if used), barlow/reducer, and eyepiece). Hence, be aware that you may not be able to reach focus with all eyepieces or in all configurations with a given barlow/reducer.
Total length (including external thread) = 19.4mm (0.76"); Total length (excluding external thread) = 16mm (0.63"); Clear Aperture = 38.5mm (1.52"); Weight = 2.3 oz.; Made in Canada.
Reviews
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Jun 26, 2015
Reduce you focal length
Pros:Strong Construction,Easy to Use,Lightweight,Accurate,Compact,Quality Lenses
Cons: Comments:Very useful for getting wider views with good optics.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
crsrs New Member
- Skill Level
- Unknown
- Time with Product
- Unknown
- User Notes:
- Review by crsrs of San Tan Valley, AZ.
Nov 29, 2013Fantstic option for a reducer
Pros:Lightweight,Easy to Use,Quality Lenses,Strong Construction,Compact
Cons: Comments:This focal reducer works great with my eyepieces in my Nexstar 9.25 SCT telescope. I have plenty of back focus to work with, and I love the way this lens simply threads onto my eyepieces. I use it on my ES 100 degree 20mm eyepiece to acheive the the focal length of a 30mm eyepiece. The view is very nice with a somewhat corrective effect yeilding a flat field and no coma. This is a great option, and I like it very much.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Oct 11, 2013Works as intended
Pros:Compact,Easy to Use,Strong Construction,Lightweight
Cons: Comments:I used to have the SCT reducer but returned that since screwing and unscrewing from the back of the OTA of my Nexstar 8se got annoying after a while. I use this everytime I do my short exposures AP. The only downside of this item is that it doesn't flatten the field. Otherwise, works great for what I need for.
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
AstroGuy1 New Member
- Skill Level
- Unknown
- Time with Product
- Unknown
- User Notes:
- Review by prk9h of Virginia.
Dec 1, 2008Antares 0.5x 2" FR
Pros:Wider true FOV
Cons:Lens can be scratched
Comments:I've used this piece a few times visually with my Celestron C6-S and some 2" EPs. I really like the wider field views it gives with my 2" 30mm EP, and it also sharpens up the edges of the FOV. With it I can see the whole of Orion's sword. It's a great buy for the money. The only problem is that because of the design you have to be careful not to scratch the lens
Bottom Line: Would you recommend this item? YesThis review was provided courtesy of AgenaAstro.com
Oct 26, 2007Antares 0.5x 2" FR
Pros:Wider true FOV
Cons:Because of the design you have to be careful not to scratch the lens
Comments:I've used this piece a few times visually with my Celestron C6-S and some 2" EPs. I really like the wider field views it gives with my 2" 30mm EP, and it also sharpens up the edges of the FOV. With it I can see the whole of Orion's sword. It's a great buy for the money.
Bottom Line: Would you recommend this item? YesSort by
