iPhone as negative viewer

[Jamie123]

Now I'm sure some of you know this already. The iPhone has a setting called "White on Black" (Settings->General->Accessability) which inverts all the colors on the screen. You can set it so it's activated and deactivated by a triple click on the home button.

This function is, of course, there so you can read white text on black for better readability but I just found out that it actually makes for a decent live neg viewer. Turn on the camera, activate the function and view some negs on a light table. Obviously it only works with b&w film and not with color due to the orange mask. It's also better for medium format and bigger sizes although 35mm works, too, if you only need a basic idea of what's on the image.

This made me think a bit further. For a tech savvy programmer it shouldn't be that hard to write an app that allows for the inversion to compensate for the orange mask and maybe do basic functions like contrast adjustment. Am I wrong? Or does Apple not let iOS app developers mess with the live image from the camera or the screen image in general?

In any case, I think if someone made this app I would pay a few dollars for it. Well, actually, I think I should get it for free because I came up with the idea but I'm sure others would pay for it

Such an app, together with an iPad as lighttable, would make for a very handy neg viewer while you travel

[keytarjunkie]

Yup the iphone is a pretty cool little gadget. Someone I follow on tumblr does this a lot using a loupe:
http://undertherain.com/post/1166356...ng-about-how-i

more examples:
http://undertherain.com/post/9719224...-loupe-kristin

It would be nice if there was an app that compensated for the orange mask.

[Jamie123]

Originally Posted by keytarjunkie

Yup the iphone is a pretty cool little gadget. Someone I follow on tumblr does this a lot using a loupe:
http://undertherain.com/post/1166356...ng-about-how-i

more examples:
http://undertherain.com/post/9719224...-loupe-kristin

It would be nice if there was an app that compensated for the orange mask.

Yes, that's not quite the same, though. The guy just takes an image and then inverts it in photoshop or some app on the iPhone. I'm also not quite sure why he uses a loupe as all it seems to do is distort the image. Zooming would probably yield a better result and with medium format you can get close enough so it almost fills the frame.

In any case, what I find interesting about the camera method is that it gives you a live image. Basically like a mini Tamron Fotovix.

[Jamie123]

Now we just have to get the attention of someone who actually knows how to develop iPhone apps

[RFluhver]

I've just tried this and it works! Absolutely bloody brilliant. Made my day.

But I have just added my own variation to this. What I did just now is to place my loupe on top of the iPhone to magnify the image. Works perfectly.

[hans voralberg]

Jamie can you post a pic? I'm not quite sure I got it yet.

[Jamie123]

Originally Posted by hans voralberg

Jamie can you post a pic? I'm not quite sure I got it yet.

I'll try to upload a picture or a video later. But anyways, the way it works is, when you turn on the 'white on black' option all the colors on the screen are inverted. So black is white, blue is yellow, green is purple, etc. etc. This means that when you turn on this function while you have the camera on, the screen will show you everything in inverted colors. So when you then aim it at a negative on a light table you see the inverted negative, i.e. the positive.
But like I said, it only works with b&w as the with color neg the inverted image is just blue due to the orange mask.

If you have an iPhone, do the following. Go to Settings -> General -> Accessability. Then scroll all the way down and select Triple-click Home -> Toggle White on Black. You'll then notice that everytime you click the home button three times you'll see the screen inverted.

[Ezzie]

I use an app called "Just Light" to view negs on the iPhone. A: Can be used a torch, albeit a very faint one. Or as a light table. Though you do see the pixels of the screen under the loupe. Not ideal, but better than nothing.

[Jamie123]

Originally Posted by Ezzie

I use an app called "Just Light" to view negs on the iPhone. A: Can be used a torch, albeit a very faint one. Or as a light table. Though you do see the pixels of the screen under the loupe. Not ideal, but better than nothing.

Yes, but that's not what I mean. I'm not talking about the iPhone screen as a light table, I'm talking about using the iPhone's camera to view the negs.

By the way, I searched the App store and it seem like there are a few apps that attempt to do something like I'm talking about. There's an app called "Negative Cam" which has the advantage that it gives a bw reversed image so you can at least view color negs reversed in monochrome.

What this app shows, however, is that there's clearly no restrictions for iOS developers to mess with the live feed image of the camera. So basically what would need to be made is a simple camera app that iinverts the image, allows for orange mask compensation and contrast control, all during the live camera feed.

[Pherdinand]

I have a friend who writes apps for iPhone, and his friend the same for Android.
His first reaction was, it is probably for such a reduced "market" that it's not really worth the effort.
But i'll try to convince him.

[Pherdinand]

Originally Posted by Jamie123

If you have an iPhone, do the following. Go to Settings -> General -> Accessability. Then scroll all the way down and select Triple-click Home -> Toggle White on Black.

i don't have an Accessibility menu there!! (3G phone here)
is it only on the newest OS?

[Jamie123]

Originally Posted by Pherdinand

I have a friend who writes apps for iPhone, and his friend the same for Android.
His first reaction was, it is probably for such a reduced "market" that it's not really worth the effort.
But i'll try to convince him.

Yes, please do . I'm sure the market is relatively small and no one will get rich from this idea but at the same time I think it should be relatively easy to program for someone who knows what they're doing. I could see people paying around $2.99 for it. Personally I would even pay $5 for it although I'm sure some people would then start complaining about the limited functionality in relation to the price.

Originally Posted by Pherdinand

i don't have an Accessibility menu there!! (3G phone here)
is it only on the newest OS?

I suppose it's only on iOS 5 then. I have an iPhone 4s and it's my first iPhone so I don't know at what point they added this function. But you can download an app called "Negative Cam" that will give you a monochrome negative image. The Lite version is free.
There's also an App called "Hello Photo" that serves both as a light table for iPads and inverts images after capture. But while it has a color balance and brightness adjustment slider for the light table part, there's no compensation for the orange mask with negative capture. And the negative effect isn't applied during the live view.

[Jamie123]

Ok, so I just figured out a DYI fix for the orange mask problem. Got out the Rosco gel filter samples and used a blue gel filter over the camera lens. Supergel *361 (Hemsley Blue) seems to work fairly well with Portra films. The image looks a bit washed out but it's ok to give you a general idea of what's on. The problem is that the camera underexposes due to the bright light source. You get a much better picture if you aim the center patch of the camera at something dark.

[willie_901]

It turns out the iPad has the same black on white option.

[Colin Corneau]

I have steady hands, but there's too much hand shake holding an iPhone above a neg on a light table...loupe works much better.

An aside: I often use an old 50mm lens as an impromptu loupe. Works very well

[retnull]

Brilliant trick -- very useful, thanks !!

[Jamie123]

Originally Posted by Colin Corneau

I have steady hands, but there's too much hand shake holding an iPhone above a neg on a light table...loupe works much better.

An aside: I often use an old 50mm lens as an impromptu loupe. Works very well

Yes, a loupe works well for judging sharpness in a neg and, as you say, old 50mm lenses work very well, but a loupe doesn't invert the colors.

Anyways, I did a few more tests and, unsurprisingly, it works best with 4x5 film. Together with the blue filter over the lens you get a really great preview of the image.

[sepiareverb]

my shutter speed dial image at left was shot with a loupe and my iPhone 4.

[Jamie123]

One more thing. If you use a camera app that lets you lock exposure (I have one called 6x7 that has a 6x7 crop) you don't have the problem of the camera adjusting for the brightness of the lighttable all the time.

I put the piece of blue gel filter in the back of my iPhone case so I always have it with me. Now whenever I pick up the film from the lab I can get a glimpse of what's on the negs by holding them up to the sky (on a cloudy day) and viewing them with my iPhone.

If anyone wants to design this app, here's what it needs to incorporate:

- Inverted colors (this isn't essential as the function is already there but you might aswell add it in the app)
- Orange mask compensation
- exposure lock, or better even, manual exposure setting.

That's basically it. Someone please make this

[f16sunshine]

Cool idea. Thanks!

[Braeside]

There is one on the app store - search for Positron.

[cambolt]

http://undertherain.com/post/1166356...ng-about-how-i

Old thread, I know

[Jamie123]

Originally Posted by Braeside

There is one on the app store - search for Positron.

Thanks! That app wasn't there last time I checked. Had to log in to the US app store to get it, though, as a search on my own countries app store only showed me a game app called 'positron' and a bunch of apps about sex positions.

The app is pretty nice as it lets you increase saturation and compensate for the orange mask. Only bummer is that it doesn't display the full screen image thus making the preview fairly small.

[Jamie123]

Originally Posted by cambolt

http://undertherain.com/post/1166356...ng-about-how-i

Old thread, I know

See first reply in the thread.

What that guy does is actually just using the camera from his iPhone to take a picture of the negs and then invert them in postprocessing. Nothing special about that as you can use any other camera or cameraphone for that. What this thread was about was using the inversion function that is already built in in the iOS preferences in order to get a live image neg viewer.

[larslp]

Hello all, reviving this to help out other googlers, googling their way to this thread. I use "Softbox Pro" for iPad to make a blue-cyan light table, and "Camera +" for iPhone to lock white balance, exposure & focus.

Along with the inverted screen trick (which I picked up from this thread, thanks a lot Jamie123), it works surprisingly well.