Still have questions re shooting film

Rob MacKillop

Edinburgh Correspondent
On Sunday I shot a roll of XP2 with the Canon AE1P. I used an orange filter, and changed the ISO or ASA to 200 instead of the recommended 400. I did this as an experiment, just to see what would happen. Well, nothing disastrous happened, the world didn't end, and all the shots came out pretty well. But I'm curious about what really actually happened. I have a few questions:

1. Is changing 400 to 200 pulling or pushing?

2. Is this the recommended action when using a filter? My thinking is that the filter would darken the exposure, and choosing ISO 200 would lighten it, balancing it out. Is this right? The point being that the filter would bring more detail to clouds, for instance, while the shift of ISO would preserve a "middling" exposure.

3. Should I have asked the Kodak Shop, who developed it, to compensate for my ISO choice? If so, what should I have said, and what effect would that have had on the outcome?

4. What would have happened if I had changed the ISO to 800 or 3200?

5. Why does the manual for the AE1-P tell me not to put film in when the shutter-speed dial is on Program (i.e. auto)? I forgot this proscription, doing exactly what it told me not to do, and the world didn't end.

6. Here are two of the shots that didn't come out as well exposed as the others. The first, a car, is reproduced here exactly as it came out:

Fab.jpg

In the second, I used Nik Silver to open up the shadows, as I was sure there should have been a student walking in the shadows, and here he is:

Gradus.jpg

He was completely in the dark originally.

So, has this anything to do with the use of the filter and the shift of ISO to 200?

7. Can you change the ISO for different shots in the same roll of film? If you suspected there might be problems with detail in the shadows, should you change the ISO to 800 or higher, just for that shot?

Any comments appreciated.

@Hamish Gill @Brian Moore and @anyone else!
 
1. Neither, it's just exposing the camera at a different exposure index. You are over exposing, to you could pull process it to compensate if you wanted to.

2. if the camera reads the light through the lens, and therefore through the filter, there is no need to compensate. Your camera is ttl metered, therefore you were still just overexposing the film

3. No, it would be unlikely that they would have been able to pull process colour film. Not many labs can.

4. You would have underexposed the film. Ei800 is within the specified latitude of xp2, 3200 is not.

5. No idea, sorry

6. It would appear that the large areas of white in the centre of the frame have thrown the camera causing underexposed areas of the frames.

7. Sort of. But you wouldn't change ISO, you would change the shutter speed or aperture

Does that help? :)
 
Yes, it does, thanks. So, with ttl metering, I don't have to make any changes - understood. I was just overexposing the film. Well, for the most part they turned out alright, so I guess it didn't matter too much.

I know I can change shutter speed and/or aperture to bring out detail in shadows. I was just wondering if a change of ISO would do the job more effectively. I suppose not.

Why would anyone deliberately overexpose, and then ask a lab to pull process it?

Thanks, Hamish.
 
It looks like Hamish has answered all your questions, Rob. Don't forget though that XP2 is really colour film that can only record black and white. It has a pretty wide latitude for exposure and normally there is no need to compensate for that in development - most high street labs can't / won't anyway. If Susan does take up developing she will almost certainly not be developing XP2 at home (at least not at first).

With something like HP5, a 'normal' B&W film, the factory EI is ISO 400 and it can record detail several stops either side. In low light conditions though you might want to rate it at say ISO 1600 and then compensate by developing it for longer to extract the detail. This has the (side-)effect of increasing contrast / reducing the dynamic range - the film has been pushed. Under very high contrast lighting one can go the other way and rate a film at a lower EI than its box speed. This can appear to increase the dynamic range (or at least change rate of change of density of a negative to exposure and 'flatten' the contrast), reducing apparent contrast and you compensate for developing the film for a shorter time than normal - this is pull processing. As Hamish says, this is a whole roll decision and it is nearly impossible to mix the two on a rolll - unless you are very good with scissors and guessing were you made the change on the film in the dark!
 
Did you see this one Rob http://www.35mmc.com/02/05/2016/overexposure-latitude/
Xp2 has a very comfortable 4 stops of over to play with. If you shoot it at EI800, you can effectively change the ISO to anything between 25 and 800 ISO (5 stops) as you are shooting, and provided you send it to a good lab that density corrects in the scan, you'd probably not even see a difference in the result
 
The lower ther ISO with XP2 the finer the grain and wwhile it does have latitude shooting at 800EIwould be far worse with that second shot. I used a lot of XP1 then XP2 but I was usually push processing it to 1200/3200 something Ilford left off the data sheets when they released XP2 as most labs won't push/pull C41 films and the major problem was XP1 needed a non standard tine in C41 and labs didn't like it for that reason.

So if there's a lot of deep shadows and you want detail then shoot at 200 EI.

Ian
 
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Hamish, I did read that ages ago, but will do so again later this evening. It is a really good article. Hopefully this time it will make more sense to me!

Ian, thanks for that. Simple, to the point, makes sense.
 
@Hamish Gill - great article. It seems my accident of setting the ISO to 200 instead of 400 was a happy one, and I was happy with all but two shots. I have some Portra 160 - I'm wondering if I should set it at 100 or even 50?

I use AG when I feel I have a set of shots worth the expense. With prints and a CD of scans, I'm afraid that runs to £30, so it's something I could only do once a month. Otherwise, it's Boots or the Kodak shop. I think the answer is shoot less, but shoot better.
 
Colour negative film is different you might drop the EI to 125 but that'll be enough.

At some stage it's worth looking at using a separate hand held meter, it's far more accurate once you know what you are doing. I may come and show you !!!! I may be up your way soon as one of my nieces recently strted her course at at Edinburgh University.,plus I have cousins there as well.

Ian
 
Your certainly doing no harm overexposing by a stop or so. Whether or not you should is open to debate, but I find the buffer is really the joy of it.
I tend to use an external meter, the iPhone/lumu for the most part these days, I take a reading for the area of shade I want too expose for, then just snap away. It's cheating really, but since I get the results I want, I can't see it matters a huge amount.
For those who just want to take photos and not worry about the finite details of perfection, it's an approach I recommend!
 
Your certainly doing no harm overexposing by a stop or so. Whether or not you should is open to debate, but I find the buffer is really the joy of it.
I tend to use an external meter, the iPhone/lumu for the most part these days, I take a reading for the area of shade I want too expose for, then just snap away. It's cheating really, but since I get the results I want, I can't see it matters a huge amount.
For those who just want to take photos and not worry about the finite details of perfection, it's an approach I recommend!

You're actually doing the opposite of cheating, your doing what Ansel Adams and Minor White advocate with the Zone System,meter for the shadows to set exposure and then highlights to optimise development time

With XP2 or Colour negarive films metering for the shadows and placing them where you want will give you negatives that once scanned will cope remarkably well with quite contrasty situations, without having to resort to changing development.

Ian
 
Yes Ian, I'd sort of agree. Though without the knowledge of the zone system to back up the process I think it is cheating a little bit...
Though does indeed pave the way for some spot metering fun
 
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