Hi, I'm an amateur who just shot a few rolls of Efke 100 with a Holga. I know from past experience that my particular Holga tends to underexpose film...even when I have it on the wider apature setting, etc. So, with the Efke I manually held the shutter open for 5-10 seconds per shot on a partly cloudy to sunny day. I'd like for the final prints to look like they were shot in the late 1800's to early 1900's. They will be processed by the local "professional" lab, so I'm looking for any advice/info. I can give them to help advance my cause. I'm pretty sure they have very little experience with Efke. Thanks.