can a 180mm cover 8x10 at minimum distance.

[jesus_blazquez]

I have a 180mm that use with 5x7 film, today i put this lens in my 8x10 camera

and saw that at minimum distance aprox 60cm the lens covers the entire format.

is this possible ?

[nowherefound]

It depends on the lens, a 18cm protar can easily cover 8x10

[armin_seeholzer]

Hi Jesus

At 1:1 macro the lens has the touble covering power then with infinity!

Hope a bell rings now in your mind!

Good day, Armin

[jesus_blazquez]

Sorry the lens is a schneider symmar -s 5,6/180mm multicoated made for linhof serial number 14 101 614 mounts in modern compur 1

[pico_digoliardi]

Certainly it is possible, if I understand correctly that your subject is very close, about 23". The image circle gets larger as you extend the bellows.

 

How is coverage at infinity (approx 7" bellows draw)?

[michael_alpert1]

I believe that for a normal lens the image-circle at infinity is half the diameter of the image-circle when the lens is at used a 1.1 ratio. The sharp part of the image circle needs to reach 300mm or more. So any normal 5x7 lens will work on a 8x10 camera when used in the close-in "table-top" range or the macro range. Depending on the lens, movement might be restricted. Image quality is another matter; with some lenses, image quality might decrease significantly.

[dave_s]

Jesus, you are correct. At f/22, a 180mm Symmar should cover 8 x 10 when the lens is 80cm from the subject. You can get the optical data from the Schneider website. Your more conversative estimate of 60cm is probably because you were testing with the aperture open.

[mb81]

I've actually seen a 90mm lens cover 8x10. It all depends on the lens. But with a lens that wide, you would want an 8x10 camera that focuses with the rear standard rather than the front.

[leonard_evens]

Generally do the following. Take the ratio of the subject distance to the focal length and subtract 1. Then take the reciprocal. That will give you the percentage increase in the size of the image circle at that subject distance when compared to the image circle at infinity. In this case, 600/180 = 7.5. The increase in size would be 1/6.5 which is about 0.15 or 15 percent. If the lens covers 5 x 7 at infinity, it covers roughly 6.5 x 8 inches at 600 mm. So a lens that barely covers 5 x 7 at infinity wouldn't do it. But if it had an image circle at infinity of roughly 280 mm or more, it would cover 8 x 10 at 600 mm.

[jim_galli4]

It doesn't take much of an angle to cover an 8X10 diagonal from 24" away. I think you'd find your 150mm enlarger lens would also cover.