I've been experimenting with Crowd Images, to try and see how faint objects one can pull out of all the data. That has also been very interesting, as I've learned a lot about apparent magnitude on the way.

Apparent magnitude is measured and calculated using different filters, and different standards. Sloan DSS uses at least five different filters. Some objects are a lot fainter in red than they are in green and vice versa.

I have therefore been searching for objects that were faint in both red and green wavelengths. The object with the highest magnitude I've been able to identify clearly in the image, is Gmag25.2 and Rmag24.2. I've found objects with one magnitude higher than 27, but then the other magnitude is much lower, like 22-23.

Object info @VizieR

This image was made in an attempt to get the field as deep as possible, so please disregard the aesthetics. The "glow" in the lower right corner is due to the star HD 98388 with a magnitude of 11.3.

I have included the image in full resolution, a half resolution with object marked, a closeup and a screen dump from Aladin showing the different magnitudes and the object ID.

156 images of Leo Triplet and NGC 3628 were combined. Minimum coverage is an average of 97 images (at the edges of the image).

Image Credits (thanks for sharing your data!

Adam Evans, Alvinillo, Andrea Pistocchini, Angel Requena, Anton, Armelle & Eric, AstroGabe, AstroGG, Astroluc63, Ben Browning, bert.seltzer, Bob Familiar, budman1961, Cano Vääri, Carsten Frenzl, chripell, Cobbler, Cody Garges, Creedence, David L Milligan, Eduardo Mariño, Epicycle, Eric Gorski, Ferran Ginebrosa, Flavastro, fragro, FranckIM06, Fred Locklear, Fredrik Ödling, Fryns, geco71, Gerardo Blanco, harbinjer, Heiko Günther, Hewholooks, jdiwnab, John Bowles, Jorge A. Loffler, jpstanley, Juan Lozano, Jürgen Kemmerer, Jussi Kantola, Ken_Lord, Ljubinko Jovanovic, Luca Argalia, M.W.Hoy, Marc Van Norden, Marcelo Domingues, Matthew, Maxvlt, Michael Karrer, Mike Durkin, Miodrag Sekulic, Morten Balling, Morten La Cour, NicolasP, PaulHutchinson, Pavel (sypai) Syrin, pfile, pbkwee, Pete Collins, Peter Williamson, Phillip Seeber, Ram Viswanathan, Rhett Herring, Richie Jarvis, RIKY, Rob Glover, Roberto Ferrero, s58y, Salvatore Iovene, Salvopa, samuele, Scott Mitchell, Sendell, Serge, Shane Poage, Stephen Rahn, Steve Elliott, Steve Yan, stevebryson, Surfus_1980, theilr, Tim, Tom Harrison, Vincent Bhm, Wayne Young, zemt-fr.