Lenses for FilmLab on 35mm films


U@ColSebastianMoran thank you forthe suggestions.
I’ve discovered that holding for a couple of seconds your finger locks focus in iphone default camera app.
This helps a little.
From the zeiss website:

The macro-zoom lens with a focal length of 40 to 80 millimeters is the first and only smartphone accessory lens with a variable focal length setting. In combination with the optics of the smartphone camera, turning the ring does not increase or reduce the field of view. The ring functions much like a manual focus with which different planes can be set into focus. Depending on the setting, objects that are three to five centimeters away or five to eight centimeters away can be captured, enabling the full-frame razor-sharp capture of objects approximately three to twelve centimeters in size using the macro-zoom lens.
The supplied detachable semi-transparent diffuser can be used as a spacer. This ensures that the object is illuminated evenly and enables convenient focusing, even with a short object distance and a shallow depth of field.

I have attached a screenshot of film lab positive because the app crash when I try to save the image to camera roll

My image has been taken on the amazon river in colombia two years ago. Thank you for the pleasing comparison :wink:


Interesting that the present it that way.

EDIT 12/19: Previous comments removed. See further posts below.


@ColSebastianMoran I would like to build some simple rig to make acquiring negatives with my iPhone as easy as possible.
The idea is to have the phone mounted on a support standing 35/40mm from the lightpad and to be able to move the film to the correct frame, scan and repeat.

What you are suggesting is to leave the focusing ring of the exolens to a fixed position, let say, half run and letting the iphone autofocus do the job, is it correct?
My question is: is there some method to know wich is the best focusing/focal ring position to allow the iPhone to get the best result?
If it depends on the distance between sensor and film let assume they are 4cm far from each other.
Thank you for your help


I have the same thought. A box about 1.5" high, maybe 3x5" horizontally. iPhone sits on top, held perfectly level. Hole in top for the lens to poke through. Black inside the box so there are no reflections. Set the height so that the lens focuses perfectly on the full 35mm frame.

One more tip: With a backlit subject (like our negatives on a light pad) you can get reflections off the lens hood. When I build my box, I might remove the lens hood.


Focusing with the Zeiss Macro lens: I have done more reading and experiments, and I have changed my mind from previous comments, which I have removed above.

Mauro is correct, turning the “zoom” doesn’t change the image size very much (but it does change a little). Instead, this mainly changes the range in which the iPhone AF can focus.

To focus on larger object, say 2" to 5" long, looking into the front of the lens, turn it clockwise. Zeiss says this allows focus from “five to eight cm away.” With my mount, the Zeiss label is now at the side of the camera, like this:


To focus on small objects, say less than 2", down to about 1" in length, looking into the front of the lens, turn it counter-clockwise.
Zeiss says this allow focus on objects from “three to five cm away.” With my mount, the Zeiss label is now pointing at the Apple logo, like this:


OK, then how to use the lens for capturing a 35mm negative area 1.5" in length? For this size object, the close focus setting on the zoom gives a much better resolution. I now suggest, for 35mm captures, use the close setting, looking into the lens turn it counter clockwise, and bring the camera right up to capture only the length of the negative image.

Here’s the resolution comparison, marks on paper, actual pixels, subject length 1.5":

This zoom control is incredibly confusing. My suggestion: Figure out for sure which setting gives closest focus by taking a photo of a 1" subject, filling the frame. Use that setting to capture 35mm shots.


@abe I am going to suggest a very specific feature request for macro lens users.
I know this sounds as (and probably is) a super specific request, but I’ve been able to find a camera app called “Halide” that allows visual and manual focus control via a slider.
More intestestingly the app lets you lock the focus to any desired distance, for example you can set the focus to the shorter distance available. It also offer a feature called “focus peaking” that uses a green noise effect to highlight the in focus area of the image:

You can barely get the same result by framing a very close object with the iPhone default camera app and touching the screen for a couple of seconds (focus lock).
This could be very handy with any external lens that has (a kind of) focus control as the exolens’ one.
So please think about adding some kind of manual focus control or a ‘set minimum focus distance’ option, hidden somewhere, in the future.
Thank you.


I think I’ve found a good workflow using the “focus peaking” and “manual focus” feature from a third party camera APP.
Here you can see a screenshot of the scanning process:

I place the iPhone on some kind of support at tge desired distance from the film (about 4cm)
I set iPhone focus ( via manual fucus) to the minimum distance.
I enable the focusing aid feature called ‘focus peaking’.
Then I rotate the Exolens ring since I have the perfect focus (think to a focus finder in a dark room).
Take the picture (this app also supports RAW format).
Open the file in film lab for cropping, perspective correction and color invert.

Note that the ‘manual focus’ + ‘focusing aid’ features are very handy also if you are not using an external macro lens.

Original shot (b&w negative)

FilmLab positive

Original shot (Color negative)

FilmLab positive

Final images looks overxoosed to me but the original negative may be overexposed to because I shot mostly without using an exposure meter (and I often fail) but it may also be related to the lightpad and iPhone auto exposure combo.


Mauro, I think you have a good approach. As long as you have the distance in a viable range for iPhone focus, this should work very well.


FWIW, and off topic for this thread: I find that FilmLab is generally giving a too-bright conversion.


I will. I definitely want to have appropriate manual controls for people who know what they’re doing and want to override the automatic settings.

It is. The new color conversion will fix this :slight_smile:. Stay tuned!



@abe thank you for your answer, your effords and your interesting newsletter on 2017.
I wish you and your family a great new year.


Some new test today using exolens macro, you can see a video of accurate focusing aid with third party photo app:

And here you can find the result:

The lens really does a good job!
Here thi final shot from filmlab and some postprocessing:


Looks good Mauro. I’m convinced with a good macro add-on lens, we will be able to do 12MPx “phone scans” that will print 8x10 or 11x14.’’

Just for clarity, that’s the Zeiss Exolens Macro. There is also a non-Zeiss Exolens that’s much less capable ($20 item).


Heads up to interested: There is an Exolens Zeiss on eBay right now from Adorama for reasonable price $120 or make offer. It’s the lens only, no bracket, so you would need a bracket or adapter from another Exolens by Zeiss item.

This is the best iPhone macro lens for shooting 35mm negatives.

(Note: There is another Exolens product, no mention of Zeiss. It’s junk. Their brackets look like they might fit the Zeiss lenses, but they DO NOT. You’ll need bracket or adapter from an Exolens Zeiss item.)

eBay search: “Exolens Zeiss Macro”


AND, even better deal from a UK seller. US $85 including shipping to US.

eBay search: “Exolens Zeiss Macro”


Out of curiosity…what is the cheapest lens you could get that would achieve to fill the 35mm frame as discussed here?
Or alternatively, the type of lens?
Such as from: https://www.surplusshed.com/search_lenses.php


There are cheap iPhone macro lenses. The quality (particularly distortion) is awful, but they are cheap. I don’t know if they cover the full 35mm frame.

I have two to recommend:

  • Moment Macro, probably $120, doesn’t quite cover the full 35mm frame. Superb quality. You can find this company on the web today and buy directly from them. You’ll need to buy a case matching your phone model.
  • Zeiss Exolens Pro Macro (Vario-Proxar), also superb, does cover the full 35mm frame. Find on eBay. Today, you can buy for $109 from a seller in Turkey (he’s a good seller; I’ve bought from him). Note: I think this only fits iPhones through 7 Plus.

While on the subject, I think the iPhone 6s is a sweetspot in current price/performance for shooting 35mm with these lenses.


Thanks for the info on these lenses.
I know the quality would not be even close to a $100 lens, but if one were to choose a lens from surplushed…would 25mm focal length ACH lens be the best? Not sure of diameter.
Mostly looking to experiment


@ColSebastianMoran I ask because the Moment Macro Lens you’ve mentioned has a 25mm focal length, same with the Sandmarc Macro lens. I think 25mm focal length = 10x


Sorry, I do not know the answer to your question.

Quick google shows the Sandmarc Macro lens was sold for close to $100, and it’s an iphone accessory, so it might be higher quality. I say give it a try.

I do have one of the very cheap (~$30) iPhone accessory macro lenses. It has wicked distortion, as in the image below.