In Search of the Holy Grail of Mobile Photo Editing

I occasionally use iPhoto on iOS to clean up pictures to share while I am on the go. That is, if I am using an image from the built-in camera app or uploaded from my Wifi-capable Canon PowerShot S110. If I shoot something with Hipstamatic I usually just share the shot without any editing, and then clean it up later on my Mac in Photoshop if there is something I want to change or improve.

I’ve been travelling a lot recently and I’d like to have a fully mobile, professional-quality, photo processing solution with me on the road. Usually I do all my post-processing on my desktop Mac after returning home from a trip. But for longer trips, I’d like to being to do some post-processing on the go. For example, I’m going to Europe for two months this spring and will only be taking my cameras, iPhone, and iPad — no laptop (well, I don’t own one anyway). Normally, I don’t even carry my iPad while travelling, but this time we will mostly be staying with friends and family, so I don’t mind lugging it along.

There is one serious limitation to using an iOS-only post-processing photography workflow — there are no RAW photo editing iOS apps. While the iPad can import RAW files via the camera adaptor kit, there is no software available on iOS with which to take full advantage of the RAW camera data. (BTW, Macworld has a nice article about using the iPad in your photography workflow.) The holy grail would be the equivalent of Lightroom or Adobe Camera Raw on iOS.

In the absence of the holy grail, I decided to compare a few iPad photo editing apps to assess there strengths and weaknesses. My basic evaluation criteria was to what degree I could use each app to do my basic post-processing operations:

• color balancing;
• contrast adjustment;
• selective dodging and burning (lightening and darkening for you new-school photographers);
• cropping;
• vignetting or de-vignetting;
• sharpening;
• black and white conversion;
• batch processing; etc.

The ability to apply filters or effects was secondary in my evaluation. I didn’t even consider sharing capabilities. Again, I’m looking for something I can use to make my images look as good as possible (100%) using only an iPad (or iPhone), so I can shoot, edit, and share professional-quality photos I can be proud of while on the road.

The Apps

Photos

The built-in Apple Photos app has some editing features, so let’s start there. The tools at our disposal are: rotate, enhance, red-eye (reduction presumably), and crop. The crop tool is useful, as is rotate for those times when your cameras orientation sensor gets confused (looking up or down at an extreme angle). But rotate only works in 90° increments so it does not work for straightening slightly crooked photos. The improvements offered by the enhance feature are minimal (basic contrast correction as far as I can tell). I can’t speak to the quality of the red-eye feature as I so rarely use flash that my subjects never have the chance to get red-eye. That, and the fact that my wife blinks a lot, so even if I use a flash, hers eye are probably going to be closed anyway. (Pro tip I learned from Steve McCurry who shot the last roll of Kodachrome ever manufactured and who needed to make every one of thirty-six exposures count: give your subject a countdown from 3 to 1, tell them to pre-blink on 2, and then take the picture on 1).

iPhoto

iPhoto was the first serious photo editor released for iOS. And in many ways it is still the best. The UI is a bit confusing and clunky, but generally usable. The functionality is excellent and for a $5 upgrade over the built-in Photos app you get an advanced straightener; contrast and saturation correction sliders; a crop tool with free, constrained, or ratio modes; local adjustment brushes; and effects including gradient neutral density, vignette, black and white, vintage, toning, etc.

I try to get things right in camera as much as I can. Correct composition and crop. Proper white balance and exposure. But I still consider images just out of the camera to be about 75% complete. With iPhoto I can elevate that to about 85% complete.

Photoshop Touch

The iPad version of Adobe Photoshop Touch has been available for a while now. Surprisingly, the iPhone version of Photoshop Touch was only released this past week.

Photoshop Touch for iPad is quite a capable photo editor. On the one hand it supports layers, which can be a good or bad thing depending on how you look at it. I do very little compositing. On my Mac I, when editing photos, I using Photoshop layers almost exclusively for adjustments tweaks after doing most processing in Adobe Camera Raw. The layers feature in Photoshop Touch is just in the way. Now if I could add adjustment layers, I’d be a fan. But not yet.

One of the tools I use a lot on my Mac, be it in Adobe Camera Raw or in Photoshop, is the curves adjustment tool. This goes way back to my days as a scanner operator in pre-press. Thankfully, Photoshop Touch has curves and levels adjustment tools.

Photoshop Touch’s crop and rotate tools are superior to iPhoto’s due to the fact that you can enter numerical adjustments. Skew and reflect tools are also available. There is a comprehensive choice of selection, drawing, cloning, and touch-up tools. I can’t say much about the supplied effects, except that there are some.

With Photoshop Touch I feel I can get done about 90% of what I usually do on the desktop (accepting the fact that RAW processing is missing).

Snapseed

Snapseed, by Nik Software (a Google Acquisition), is an innovate app with a large suite of both basic tools and powerful effects. The UI is unique among apps I have tried, but is highly usable once you understand the basics. It has almost all the features of Photoshop Touch minus layers and the drawing and selections tools. And in a lot of ways the Snapseed offering is better. It has a nice Structure function in its Details suite (equivelant to Adobe Camera Raw’s Clarity function). I often prefer to use this type of local contrast enhancement instead of making global contrast changes (which I usually do with curves).

For basic photo post-processing, Snapseed seems like it could get me to 93% completeness. There are still several things missing though.

In particular, a histogram would help to ensure whites and blacks are not being clipped and make overall analysis easier.

The white balance tool leaves something to be desired. Why can’t they just offer an eyedropper for sampling neutrals?

The effects suite of Snapseed is better than any I have seen elsewhere. For the occasions when I want to get a little messy this is going to be my go-to app. One of the reasons that the effects are so good is that they are all parametrically driven. Every aspect of an effect can be adjusted.

This brings me to a suggestion that would make this a 95% app. Since all the adjustments and effects are parametric, having the ability to store personal presets would be amazing. Well, in the mobile app world this would be amazing. In the real world, the ability to store presets and batch process images is a necessity. So far I have not seen any iPad/iPhone app with such essential capabilities, with one exception. Which brings us to B&W Lab.

B&W Lab

Between 5 and 10% of the images I shoot I end up converting to black and white (or some sort of monochrome).

More photographers should explore black and white. Just because most digital cameras capture color images all the time, does not mean this is the best way to represent a scene or the photographers vision. When the photo is about shape, line, texture, or structure, it would probably be a more powerful image if rendered in black and white.

B&W Labs is the best app I have found for making black and white conversions on the iPad. It surpasses Snapseed’s Black and White suite. In Beginner mode there are very usable presets provided. Additionally, after you choose a starting filter you can modify every parameter of the preset via sliders. (The method of choosing a starting point in Expert mode is a little different). There is even a useable Tone Curve tool. You are limited to five handles on the curve, but that is more than enough for most situations. Performance is little slow, but not horrendous.

B&W Lab allows you to load the settings from any previously edited image into the current session. The feature, labeled History, is a little counter intuitive as are most of the UI elements. I’ve gotten used to the idiosyncrasies though and have no problem making great black and white conversions with this app. If they could allow you to batch apply History settings, then this app would be amazing. A histogram wouldn’t hurt either.

For black and white processing only, this app actually gets me about 98% completeness.

Image Blender

Image Blender is a little different from the other apps reviewed here, designed purely for compositing two images together.

The art of multiple exposure is almost lost in this era where every click of the shutter button results in a separate image file. In the age of film, creating multiple exposures was easy. Most cameras had the option to cock the shutter without advancing the film. Other cameras, like my 4×5 field camera, required the photographer to change film after each shot, and if they didn’t they could keep exposing the same piece of film over and over. (There used to be studio techniques involving multiple strobe flash bursts, one after the other, that required the ability to do in-camera multiple exposures. Alas, those techniques are lost to us digital photographers.) But I digress.

Much like Photoshop Touch layers, Image Blender allows you to set the blending mode between two images as well as the opacity of the top image. The output file always has the resolution of the smallest input file (not a problem if both inputs are the same size). Image Blender also has some masking features that I haven’t played around with yet.

Image Blender wouldn’t ever be my first choice for general post-processing of course. That’s not what it is designed for. But if I want to make a conceptual multiple exposure from two images, I would probably use it over Photoshop Touch layers. And if I need to make an illustration or banner for a blog post, I might use its masking features, although I might just go to the more familiar Photoshop Touch instead.

Conclusion

All of the main photo editing apps mentioned here — iPhoto, Photoshop Touch, Snapseed — were released over a year ago. That’s not to say nothing new is happening in this space. These apps are actively being maintained with updates coming out about quarterly. They keep getting better, but in my view as a photographer, looking for a professional mobile editing and workflow solution, there is still a lot of room for improvement. Whichever developer first releases a RAW processor with camera profiles and lens correction capabilities is going to make a lot of money.

In terms of display quality, processor power, and connectivity, I still believe in the promise of the iPad as a professional, mobile, post-processing solution. But at the moment, even after editing and sharing some of my creations while on the road, I will still be going back into Adobe Camera Raw and Photoshop on my Mac to re-edit images in an effort to eek out those few remaining percentage points of quality. Nothing but 100% will do.

Samples

For each app reviewed, I used an image from my iPad camera as a starting point and pushed the software to see what it could do. In iPhoto and Photoshop Touch, I just tried to improve upon the output of the iPad’s camera. I didn’t necessarily do the same operations in each app. I just used the tools at hand to maximize the image’s potential (not that it was a great image to begin with). I did the same in Snapseed, but have provided here a sample of one of the Vintage filters instead. The B&W Lab and Image Blender samples are self explanatory, I hope.