Audubon mk 11 for Astronomy (1 Viewer)

Hi all. I have a chance to buy a pair of old Audubon mk 11. This pair has the gold stripe. From the late 70s I think . Says. there in near mint condition . Or do you think i would be better getting an Hr 5 pair Asking for --£120. Any advice would be welcome regards price . Thanks

Welcome to Bird Forum. I know a fair amount about Swift Audubons, but not much about astronomy. Still, I'll venture a few comments that might be of assistance.

The large body Audubons of the 1970's were fully coated, but not multicoated. They were very well made, but unfortunately prone to flares and reflections. The original HR/5 models issued by Swift-Pyser in the early 1980s had multicoatings, but not full multicoatings (see pgs. 14 and 16 of the report posted HERE). So, the value, in part, depends upon which HR/5 is available to you. Nowadays I think a Fully Multicoated HR/5 in excellent condition would be worth what's being asked for it.

Now, with regard to astronomy tasks, consider that all objects in the field are at optical infinity. Since the Audubon design does not incorporate a field flattener, how much appears to be in focus will be determined by the instrument's inherent field curvature and your visual accommodation capability. If you are above 50, for the most part your accommodation will be very limited and the outer field will seem to be out of focus. Fortunately, unlike other binoculars, the Audubon has very little astigmatism, so this can be largely rectified by refocusing the instrument.

Personally, I would recommend the newer HR/5, particularly if it's fully multicoated.

Ed

I have both models, and can echo everything Ed has said. My guess is that you would be paying £80 to £100 for the Gold model, if so, in my opinion the HR5 for £120 is a better buy, but as Ed said, try to get the fully multi coated version, it's a very good binocular. The Gold model does suffer from a little flare, the HR5 much less so. I am no Astronomy expert either, I have only looked at the moon now and then really, but these are primarily nature/birding binoculars, so I suspect there may be better options than either for Astronomy.

The Audubon (golden stripe or type 3b) is a very good binocular for astronomy. Of course there are better binoculars but the Audubon is performing well for astronomy.

I had the Audubon HR/5 too and sold it very quickly. The HR/5 is much more a birding binocular than the Audubon 3b. The sharpness of the HR/5 is at night not as good as the 3b and the image of the HR/5 gets soft to the edge too much by night, or dark conditions (the HR/5 is very sensitive for this). The overall sharpness of the Audubon 3b is better too and gives pin sharp star images. The HR/5 has (fully) multi coatings but the difference in brightness under the stars is small.

The 'problem' with the HR/5 is that it's a compact build binocular. For birding an important aspect but not for astronomy. Because of the HR/5 is so small it can't have the better (and larger) corrected eyepieces of the Audubon 3b. For astronomy you want a sharp image from the center to the edge as much as possible. And the Audubon 3b is without any doubt the better one for this.

The HR/5 is a fine binocular specially for birding. For astronomy go for the golden stripe Audubon.


@ EDIT My Audubon is stripped and the prisms plus eyepieces are used for the Swift Newport 10 x 50 MK II to improve it in an enormous way. Maybe an idea?

http://bino-blog.webnode.nl/news/swift-newport-10-x-50-mk-ii/ (sorry, you have to use Google translate)

Scorpius said:

@ EDIT My Audubon is stripped and the prisms plus eyepieces are used for the Swift Newport 10 x 50 MK II to improve it in an enormous way. Maybe an idea?

http://bino-blog.webnode.nl/news/swift-newport-10-x-50-mk-ii/ (sorry, you have to use Google translate)

Click to expand...

Hi Scorpius,

That sounds a great idea with the Newport, but fitting the Audubon eyepieces/lens will make it an 8.5x50 would it not? not a 10x50, or have I misunderstood what you have done?
Ben

No, it doesn't. The focal length of the Newport is not the same as the Audubon.

Focal length eyepieces for both binoculars are the same. Focal length objectives are different.