iPhone vs Henry Draper's 50min exposure

[MarkS]

Compare this 1 sec iPhone image of the Orion Nebula to the first ever image of it by Henry Draper in 1880 - a 50minute exposure:
http://io9.com/the-first-photo-of-the-orion-nebula-compared-to-one-tak-1535930753

[Rocket Pooch]

Also cars are quicker now.

[RobertM]

Have to admire the man doing a 50 min session guiding by hand, today there are words for people that do that sort of thing... Push Here Dummy

[MarkS]

Also cars are quicker now.

3000x quicker?

[JohnP]

Don't forget Mark we are also talking colour V's B&W... so we are talking 3,000 + 3,000 + 3,000 times quicker..

[Mac]

have you noticed the new star as well?

Might be just me, but.
Right hand side midle of the iphone image, One bright star, come in about 1cm to the left another star.

1880 image No star, ooking at the relative bightnesses, this should be visible on the original photo if it was there.

[MarkS]

There are a few stars missing in the old picture.  I wonder if it has anything to do with relative sensitivites at various wavelengths - film vs iPhone sensor - so the iPhone may picking up signal that the film was not sensitive to?

[Rick]

Good point, Mark. I'd guess it's very likely the film was sensitive mainly to blue, and not very sensitive at red...

[MarkS]

We might be able to confirm this by looking at the spectral classifications of the stars in the image.

[mickw]

Henry Draper's image is over 130 years old, and was hand guided.

With film grain and hand guiding he was lucky to get stars so tight.  There are also 2 other low mag stars to the lower left that have also disappeared from the iPhone snap.

The low mag stars probably blended into the nebulosity with camera movement.