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View Full Version : JML lens of about 550mm

sun of sand
12-01-2007, 09:52 AM
I was thinking about one day making a simple box camera for fun and found this JML. Most people seem to like JML 210's soooo
I was wondering if the longer lenses have been tried as the lens is pretty cheap.

What would 540mm be in larger formats/ULF... Like a 70mm in 35mm?

blaze-on
12-01-2007, 11:18 AM
Closer to a 90 in 35 I think. I've heard good things about the JML's, but haven't seen much on this focal length.

Whiteymorange
12-01-2007, 03:40 PM
View Camera Magazine published a PDF that suggested you multiply the focal length of your 35mm lens by a factor of 6 to get an equivalent 8x10 lens. That would make your 550mm on 8x10 equal to about a 90mm on a 35. In 4x5 they suggest it will give you the field of view that is roughly equivalent to a 185mm on 35.
Here's a link to that PDF (www.viewcamera.com/pdf/VC_Getting%20Started.pdf)

sun of sand
12-01-2007, 11:34 PM
I just did the 8x10 figure equivilent in my head and for whatever reason I did it this way
210 on 4x5 =70mm -or so- or 1/3 the FL
540 on 4x5 = 180mm or 1/3 FL
then take 180/2= 90mm or 1/6 FL

I just hadn't bothered to figure out the increase in film footage over 4x5 because I'm just not into math

I was thinking more like 12x14 or 14x16 or so, though. Doing more of my simple crappy math I figure the 540mm would be just about "normal" on 12x14

Whatever

I was hoping someone had experience with the longer focal lengths they offer.
On their site they give MTF results but I don't understand them, really

The 210 seems to be the sharpest (at least one of the sharpest) they offer
The 540 they list as giving like 12 l/mm center and edge compared to like 54 C/E for the 210
But I don't know how they test or what effects sharpness in longer focal lengths.

PROBABLY pretty sharp for a 12x14 or whatever contact print, though. Too hard for me to pull the trigger.

jimgalli
12-01-2007, 11:48 PM
On 11X14 it would look like a 55mm on 35.

sun of sand
12-02-2007, 09:33 AM
Mr Galli, you've never tried one of these JML's?

I'm probably not going to get it since there are others that are of known quality for little more and my fun project ain't happening for a while

Hugo Zhang
12-02-2007, 09:35 AM
I bought such a lens not long ago and have not tested it with ULF cameras yet. The seller claimed that he tried it on a 12x20" camera and it covered that format and the negative was so good that it just put other lenses into shame.