Bsrgvty

I have a film strip with TMax-400. Out of 36 frames, I pushed 10 of them to ISO 1600.

If I want it to develop in my local store.
How should I instruct them to develop my negatives?

Also what are scanning suggestions for this situation?

I have a film strip with TMax-400. Out of 36 frames, I pushed 10 of them to ISO 1600.

In the future, use the same camera ISO setting for the entire cassette. Push/pull development is done on the entire roll at once, unless you have your own darkroom.

If I want it to develop in my local store. How should I instruct them to develop my negatives?

First, decide how important the 10 frames are vs the 26. Then consider developing for the frames you consider more important.

• Standard development. The 26 will be developed appropriately. The 10 will be underdeveloped two stops.




• Push development by one stop. The 26 will be overdeveloped one stop. The 10 will be underdeveloped one stop. Based on Hueco's answer to your previous question, this should work fine.




• Push development by two stops. The 26 will overdeveloped by two stops. The 10 will appropriately developed.

Hueco mentions stand development. I know some labs do this, but it's mainly a home technique. I've tried it twice and ruined the film both times, so don't expect miracles. When starting out with home development, the best way to have it go well from the start is to do everything by the book. Then gradually start experimenting.

Also what are scanning suggestions for this situation?

As long as the density of the negatives is close to normal, you can adjust scanner settings using your "normal" process. If the negatives are too far gone either way, it'll be hopeless.

Just consider it all part of the learning process.

In case those 10 pushed shots are of great importance, there is a method to develop then without ruining (most of) the unpushed frames. This method requires scissors, a darkroom or changing bag, some basic maths and a dose of luck. Also, this will only work if the pushed frames are consecutive and on one end of the roll.

Things you have to know before you proceed

• The length of film before the first frame or the length of film after the last frame depending on whether the pushed frames are first or last on the row. You can determine this by looking at negative strips shot before with this camera.


• The amount of pushed frames (in this case 10)


• The length of the pushed frames


• How to handle scissors (most people will be able to handle this)

The method

1. Calculate the sum of the length from the first bullet with the length from the third bullet.


2. Mark the length on a tape measure and lock it, or use a piece of string (or any other material) at the calculated length


3. In a darkroom or changing bag, pull the film out of the canister. This can be done by putting two sided tape on a flexible strip of plastic or paper and inserting it into the canister until you think you might have a hold on the film. Then slowly pull out the strip. Make sure you have a light-tight container (or two if the pushed frames are at the end of the roll).


4. Using the tape measure/string, cut the film with an excess of the length of one or two frames, so you won't cut through the middle of one of the pushed frames. If the pushed frames are first on the roll, you cut the first strip you pull out of the roll. If the pushed frames are last on the roll, you remove the film entirely from the canister and cut the last bit of the film strip.


5. If the pushed frames are the first on the roll, rewind the rest of the roll back into the canister and place the cut strip in a light-tight container. If not, place both cut film strips in light-tight containers. You could use, for example, a bag for darkroom paper or a developing tank.


6. a) The tricky part is to get these strips developed. Many places that offer developing use fully automated systems and it is not unlikely their employees, expecting film rolls instead of loose strips, will mishandle the film. Therefore, make sure you explicitly communicate the state of the film strips, how they are packaged, and how they should be developed (mark the difference between the pushed strip and the unpushed strip.
   
   b) Develop yourself. In case you were thinking of starting to develop film yourself, now may be the time to do so. It would save you a lot of hassle were you to develop yourself, because you won't have to rely on a lab which could possibly mistreat the film strips given their unusual state.

n.b.

- Note that it is possible to do this if the pushed frames are consecutive but in the middle of the strip. You will end up with three separate film strips and more lost frames. Just make sure (if the pushed frames are more important) to cut through the unpushed frames, not the pushed frames.

As xiota said, don’t do this in the future. You have 10 frames that are underexposed, which would need more dev time to compensate. But, if you do that, then your 26 normal frames will overdevelop.

The best thing you can do is develop at home¹. If the 10 frames are all in a row, and preferably all to the beginning or end of the roll, then simply cut them from the roll and develop the 10 separate from the 26. This is your best bet.

If they’re interspersed (why oh why would you do this to yourself?) then I’d look at stand development². This technique relies on exhausting the developer anyway, so the impact between your over and under exposed shots should be minimal. That being said, a common developer for this is Rodinal or similar and it’s generally not used with pushed film because of the grain and acutance it really brings out of the film. Personally, I overexposed the film when it’s destined for stand development, not underexpose. But, it’s an option for you.

The final option (and probably the best for you) is to just pick a time and go for it. Do a 2 stop push and overdevelop 26 frames. Develop normally and underdevelop 10 frames. Pick a time in between and deal with the slight under/over.

I hope you’re ready to experiment. If taking shots of which you are not wanting to experiment...follow a process that you’ve established and never change the ISO mid roll!

_{1: Developing BW at home is one of the best things that you can do for your photography. Not only in finding a film/dev combo that you really love - but in having complete control of the process.}

_{2: With stand dev, you're purposefully exhausting the developer - but there still needs to be enough developer to work the film. I use Rodinal for this and use 5mL at 1:100 ratio per 35mm roll of film. Others out there use up to 10mL per roll. As xiota notes - it's an experiment until you fully understand how your process works with your film and exposures and even lighting conditions while taking the frames.}