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April 28, 2016

Tips from theLoop: Skyline Images

As you expand your photography business, you don't know what you don't know. Asking questions on theLoop to expand your knowledge is a great place to start to learn about any area of photography! With 29,000+ PPA members behind you, there's bound to be someone who has been in your shoes and can offer a word of support or advice. 

This month, we're highlighting the thread concerning skyline images, specifically how to reduce the noise in them. Check out what your fellow Loopers had to say and the beautiful images their advice helped create (complete with before and after shots): 


Jonathan Andreas: Hello! I currently travel for work and aside from my day job I make it a point to get out and shoot skylines when I am in bigger cities. Most of the time I shoot around dusk and during the night. Typically I am shooting with a ISO of 100 and as slow of a shutter as I can with a f/22 (canon 5d mark III, 24-70 f/2.8) I just started using live view and manually focusing as well- I am just looking for some tips for how to reduce my noise during the low light shots as well as some post production tips. Thanks! -Jon 

Thomas Viceconte: Are you using long exposure noise reduction in-camera? Is there a specific reason you're using f/22 for all the images? How are you processing the files in post?

Jonathan Andreas: Thanks for responding Thomas, I did not know there was an option for noise reduction in camera. I will apply that and check it out the results. I have been shooting f/22 just so I could use a long exposer. Are there negatives to using f/22? 

Eugene Lugo: Shooting at F22 will cost you some sharpness due to diffraction. I would suggest using a neutral density filter and a larger aperture if you can do that and still have enough depth of field.

Jonathan Andreas: Got it, I didn't know that. I'll try the larger aperture and look into the filter. I have been using iPhoto to process my images. Once I get home in May, I will be able to use CS6 to process my images.

Leroy Moore: Jonathan, in-camera noise reduction takes two photos. It takes your photo, then closes the shutter and takes another.  So, if you are shooting a 3 minute shot, you lose another 3 minutes while the camera takes a dark frame.  It then subtracts the noise produced in the dark frame from your original image.  It's slower and sometimes works well, depending...  You set this up in your camera's menu system.

Suggestions:  DXO Viewpoint 2 is not very expensive and can be used to correct the optical distortion you are getting. 

Fair noise reduction software includes Lightroom and some techniques with Photoshop.  Topaz labs makes a great and inexpensive de-noising software called DeNoise.

But if you want to sell large copies of these great photos, your best noise reduction that can be had is by DXO Optics Pro labs.  It also converts raw files and is a stand-alone program.  The Prime de-noising algorithms of this software are currently the best available at removing noise, but leaving detail.  I am not sure, but I think buying the bigger program may come with the Viewpoint software included.

Have fun shooting...

Jonathan Andreas: Leroy, I appreciate the feedback, I'll take a look at the programs. For future photographs do you think the neutral density filter is the way to go? Thanks!

Kevin OConnell: I shoot mostly all long exposure and paint with light. I would suggest you try shooting different f-stops as well. See how more brilliant the light is at say f13. You will see a difference in the two scapes. Also find the sweet spot of your lens for optimum detail. Very easy to do with tutorials on youtube. You probably already know to shoot during the Blue hour for the best looking skyline shots, if not try that as well. 

Tim Gray: Another thing to consider is the higher aperture numbers create the nice star-burst flare effects from direct lights (ex: the streetlights on the bridge). The trade-off is that your lens provides sharper focus and less edge distortions at the middle f-stops (f/8 - f/13).

As for the noise reduction, are you shooting RAW or JPEG? If you are shooting in RAW, then noise reduction is not applied in camera. I have not done comparisons shooting RAW with long exposure NR setting but my guess is that would only be applied for JPEG. Has anyone else tested this for RAW images?

Thomas Viceconte: You're welcome, Jonathan. In addition to all the excellent recommendations from others, you can try applying the digital lens optimizer (DLO) in Canon's Digital Photo Professional (DPP) software that comes with your camera. You can download the software from the Canon web site. DLO reduces lens aberrations and diffraction. It would be interesting to see what it does with the images that you posted. If I apply DLO to an image in DPP, I set the sharpness/unsharp mask to 0 before using DLO and make no other adjustments in DPP. I then export the file as a 16 bit TIFF and process the file in Lightroom/Photoshop. It's not needed for every image, but if you're using the extremes of a lens, it might help improve the image quality. I used this process on the attached image that I took handheld at ISO 1600. It's not perfect, but if you look in the dark areas of the image I think the noise is minimal.


Jonathan Andreas: I attached the before and after canon photo professional, just from tweaking it really quick it is a huge difference! 

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