Hands on with Hydra (Not the Serpent-like Monster)

When I saw a new app called Hydra I thought about the monster with a lot of snake heads, but I was wrong. In this case Hydra is a Universal app that can do a variety of things including HDR photos and video, shots in low light conditions, better zoomed images, and high resolution photos.

Hydra Logo

I tried most everything with the app and I’ll show you lots of samples. I did this with version 1.0 of the app on my iPhone 6. Version 1.0.1 of the app was released earlier today just before I finished this post. I made a note of several things that I’d listed as issues that were already fixed by the developer.

HDR Photos

The app will analyze the scene and then decide how many shots it needs to take (based on the brightest and darkest regions) up to a maximum of 20. It then begins snapping a lot of photos. In most cases the app took about 10 to 17 shots. Every now and then I would get a “Couldn’t take picture” message (this might be due to excessive range in the region – but I’m not positive) as it was taking photos. Once the app has taken multiple shots it combines them to get the HDR look. You get the option of B&W, Medium HDR, or Strong HDR along with a preview of each before you click the check mark to save the final photo. I would like it if you could save all three of these as an option, but you can only choose one when you save.

Below are five images: original image, HDR with built in camera, B&W with Hydra, Medium HDR with Hydra, and Strong HDR with Hydra. There are a few key regions you can look at to see the various effects: the flower region on the left side of the image, the vase in the upper center, and the chairs in the front of the scene.

Original image.
Original image.
HDR using built in camera app.
HDR using built in camera app.
B&W option from Hydra.
B&W option from Hydra.
Medium HDR from Hydra.
Medium HDR from Hydra.
Strong HDR from Hydra.
Strong HDR from Hydra.

The HDR for the built in app is somewhat geared towards situations with bright blue sky and faces in the foreground, so it didn’t do much to improve the original other than drastically dimming the area around the vase. Hydra did a great job with the Medium HDR setting for this photo. The B&W was also great. The Strong HDR was a bit overpowering in this case (for me).

HDR Video

You can see my example on YouTube where I panned the camera from a bright scene to the interior of my office. Overall the HDR video did a good job, although during the transition stage from the bright outdoors to the darker office there was a lot more noise in the video than there was in the video from the built in camera.

Here are three still images for visual comparison.

In the bright outdoor scene the HDR gives it the more vibrant look on a partly cloudy day, as opposed to the ‘drab’ look of the standard video.

Here you can see the nice effect of HDR when you look out the window on the right. Hydra still shows the blue of the sky, and a greater vibrancy to the colors of things out there. However, in this transition phase between the bright outdoors and the office there were a lot of compression artifacts (and some noise) in the video from Hydra. Apple had a bit more noise, but not many compression artifacts. You can see it when looking at the ceiling area. It’s not miserable, but in the full size video it is easily noticeable. Here are closeups from the full size video:

Compression artifacts visible in video from Hydra when going from bright scene to dark room.
Compression artifacts visible in video from Hydra when going from bright scene to dark room.
Less compression artifacts (but a bit more noise) visible in video from built in camera when going from bright scene to dark room.
Less compression artifacts (but a bit more noise) visible in video from built in camera when going from bright scene to dark room.

For the interior scene Hydra uses the HDR to get rid of the really dark areas (such as the doors in the back, or the shadowed cubicle walls in the foreground).

Lo-light Mode

Hydra uses multiple exposures to ‘amplify the light by merging up to 10 images’. I did some limited tests in a dim restaurant. I didn’t notice a big difference in the overall brightness of the image, but I did see a big reduction in noise. This was the Hydra image:


At this size you can’t see a big difference between this and the default photo app, but here is a comparison of the ceiling in the Hydra app and the built in app.


It’s very easy to see the excessive noise when using the built in camera (on the right side). The Lo-light mode of Hydra did a superb job cleaning up the image.

Zoomed Images

The app lets you create zoomed images (2x or 4x). When snapping a shot it’s kind of nice that you see your zoomed rectangular region on top of the full image. This shows that I was about to take a picture of part of a lamp.


The next two shots are small regions from a photo I took of my keyboard using the built in camera zoom, and Hydra.

Photo taken at full zoom with built in camera app.
Photo taken at full zoom with built in camera app.
Photo taken at 4x zoom with Hydra app.
Photo taken at 4x zoom with Hydra app.

The clarity of the letter M and the region around the keys is vastly better with Hydra. However, there was far more discoloration/noise in the Hydra image. I noticed the same thing in several other zoomed photos I took in this mode.

Hi-Res Mode

Hydra let’s you take a super high resolution photo (32MP image measures 4896 x 6528 pixels!) so I tried this out while I was eating a bowl of soup for lunch.


I took a small portion of the image to show the difference between the high resolution image from Hydra (on the left) and the image from the built in camera (on the right).

Image on the left side used high resolution mode with Hydra app. Right side was built in camera.
Image on the left side used high resolution mode with Hydra app. Right side was built in camera.

Hydra did a great job with the high resolution image. It’s one of those things you won’t really notice when looking at the image on your iPhone – but if you choose to print the image in the future or want to do some heavy cropping you’d appreciate the extra pixels.


This is version 1.0 of the app. Here are a few quick thoughts about a few problems.

Hydra has a built in photo viewer within the app that doesn’t separate local photos from your PhotoStream photos, so it can be confusing which images you are looking at. I was briefly confused when I’d deleted all my local images but still saw them in the Hydra app.

Changing modes within the app seems a bit “twitchy” and will often jump over the one I was trying to get to. Just a minor annoyance, and probably just my fingers being clumsy. Update: This problem seems gone in version 1.0.1 that was just released.

When viewing the photos in the photos app, the location shows up as Xinjiang (China). When I view a photo taken with the built in camera app in Lightroom it shows 38°1’21” N 78°28’12” W as my location, but Lightroom doesn’t show the “N” and “W” for the photos taken with Hydra, so I think their EXIF data is missing some information. Hopefully that will be fixed in the near future. Update: This problem was fixed in version 1.0.1. I’m no longer in Xinjiang!

When things are moving around in the scene and you are using the HDR mode there are problems. My guess is the algorithm used in the app needs a bit of tweaking. I will often see large blue or red splotches in the region where motion was taking place. Here is an example from a picture at a coffee shop. The woman was turning her head at the time. Update: The description in v 1.0.1 of the app stresses that this app is not suited to moving objects. (I still would like it to handle the splotches in a better way.)


The one other thing that you may have noticed is that all the photos from Hydra see to have a warmer tone than the built in camera app. It doesn’t really bother me since that can always be changed at a later time in another app, and sometimes it’s nice to have the warmer tone. This was more of an observation than an issue…if you know what I mean.

In a future release I’d like it if there was an option for a 2 second delay (or adjustable number of seconds) after pressing the “shoot” button – since stability with these HDR and hi-res shots are important. Also, the volume button currently doesn’t trigger a shot to happen, so I’d like it if that would get included.


Hydra has immediately become my favorite HDR app. It makes use of many images to get a really great HDR shot (Medium strength is my favorite). I don’t think there are any other apps even close right now. Since it takes so many additional shots it takes longer to capture the image it can’t really deal with motion – but I’ll always be using this app when I want a quality HDR shot with my iPhone/iPad. I can’t wait to venture in to an old historic church just so I can get some lovely HDR shots.

The Hi-res mode is impressive and will be getting used whenever I am doing a landscape shot or a pseudo-macro of flowers and such. When doing the hi-res shots I tried to find something solid to brace my hand/iPhone on, but the handheld results were great (maybe I’ve learned to have a steady hand over the years).

There are a number of features I didn’t mention such as being able to change the megapixels for various shots (you can get a 12MP HDR!) having a grid displayed, locking the orientation, etc. The app has a really nice simple interface so none of those things get in the way or distract you. Once you select a mode you can just press the nice big button to capture your shot.

The developer came out with their first update very quickly after the initial release and fixed many of the problems I’d seen. The HDR capture seems faster than version 1.0.0, and version 1.0.1 hasn’t crashed at all during my late afternoon testing.

I’m sometimes amazed at what can be done with current technology. Hydra is one of those rare apps that amazes me. Hydra is a must-have app that will be on my iPhone for many years to come.

It’s currently on sale at an introductory price of $2.99. You can see many more examples and read about the app on the Hydra homepage.