# You call that a long lens? _THIS_ is a long lens.

Discussion in 'Digital Photography' started by J. Clarke, Jan 9, 2014.

1. ### J. ClarkeGuest

<http://www.mnn.com/earth-matters/space/stories/hubbles-frontier-fields-
photos-show-galaxy-35-billion-light-years-away>

In photographer's terms, they are using a galaxy cluster 3.5 billion
light years away as a lens to image other galaxies 12 billion light
years away. Think about it--that's a 33112556654032800000000000000 mm
lens. Have no idea what the aperture is--it would be measured in
thousandes of light years, but the f ratio would still be pretty small.

J. Clarke, Jan 9, 2014

2. ### RichAGuest

The article is LOADED with errors. 3.5 billion? How about 13.5B, the actual number.

RichA, Jan 9, 2014

3. ### SandmanGuest

In article <>, RichA wrote:

> The article is LOADED with errors.

Oh, and here's the long list:

> 3.5 billion? How about 13.5B, the actual number.

Uh, one item? And it's even wrong. 3.5B is the distance to the Abell 2744
cluster, and the news is the background galaxies that are *12* billion
light years away (not 13.5).

And it's all there, right in the article.

Abell 2744:
http://en.wikipedia.org/wiki/Abell_2744

"Distance: 3,982 Mly" - Which is the distance to its center.

They used the gravity of Abell 2744 to focus light from galaxies more than
12 billion light years away. Here is the news from Nasa:

http://www.nasa.gov/content/hubble-frontier-field-abell-2744

--
Sandman[.net]

Sandman, Jan 9, 2014
4. ### Whisky-daveGuest

On Thursday, 9 January 2014 11:55:47 UTC, RichA wrote:
> The article is LOADED with errors. 3.5 billion? How about 13.5B, the actual number.

I don;t think that's corect it is 3.5 Billion not 13.5.

The cluster they are talking about at 3.5 billion ly is used to magnify objects that are more than 12 billion ly away. 13.5 bilion is almost the know edge of our universe.

Whisky-dave, Jan 9, 2014