Lenses for circular pictures on 8x10

[ic-racer]

8" is about 200mm so look for lenses with image circle around 200mm. There is a chart here with most info you will need: http://www.largeformatphotography.info/lenseslist.html

[Marko Trebusak]

8" is about 200mm so look for lenses with image circle around 200mm. There is a chart here with most info you will need: http://www.largeformatphotography.info/lenseslist.html

That chart is an usefoul resource, but not for what OP would like. Those data are for objective focused at infinity. On the other hand with a bit of trigonometry, one can calculate image circle at any distance.
Marko

[ic-racer]

That chart is an usefoul resource, but not for what OP would like. Those data are for objective focused at infinity. On the other hand with a bit of trigonometry, one can calculate image circle at any distance.
Marko

Yes, or if he has his camera and a lens handy he can use simple math and divide his (bellows draw) by (focal length) and multiply that by (image circle at infinity) to find his effective image circle.

[Leigh]

It's a linear relationship.

The IC diameter at 1:1 (life-size image) is twice that at infinity focus.

It also varies with aperture, getting smaller as the aperture gets larger (smaller f/number).
The IC you find on lens datasheets is usually three stops down from wide open, i.e. f/16 for an f/5.6 lens.

- Leigh