Ilford Ortho vs Tech Pan

I have used Tech Pan but have never used Ortho. Do you think you might be able to use it as a subsitute?

Depends on what you want to substitute...

Ilford Ortho is - orthochromatic. Red blind.
Tech pan has extended red sensitivity - just the opposite.

Thus the tonality given by the two films will be totally different, unless you're shooting monochromatic subjects.

I have used both, and they both have their uses. But for different reasons. BTW I still have a few rolls of 120 Tech Pan left

I've never used the ilford film, though I've shot TP once.

I've heard of good results from both. Some people seem to get better results from the microfilms such as copex and imagelink.

Personally, for fine-grained work, I use Efke KB25; it's not quite as fine-grained, but with the right developer, it's very close. It also has the distinct adavantage of being inexpensive.

Nice Avatar, by the way ...