Petzval lens for half plate

[mylek]

Hello,

i'm new to LF and as i'm starting to do some wet plate collodion. I'll like to know what will be the proper size Petzval lens to buy to be used on an old Deardoff 5x7 for half plates and 5x7 film. I understand that characteristics are different to contemporary lenses. I'll like to get moderate swirling.

Regards!

[Two23]

Anything at least 165mm should work, I would think.


Kent in SD

[goamules]

No, you'll need longer than that to cover 5x7. Petzvals are narrow. I'd look for an 8" if it's F4. A 7" might work if it was a slower F5.

[CCHarrison]

If you'd like moderate swirling - which typically means less coverage - you should probably look for a 1/4 plate Petzval. In doing so, you can use stops which will moderate the swirl (by stopping down and increasing coverage). If you get a 1/2 plate lens, you wont get much swirl (typically)... Depending on the brand, most fall into the 6 to 8 inch Equivalent Focus range (which would be approx 5 to 7 inch back focus).

See my Petzval article to check the specs on many different brands of Petzvals http://antiquecameras.net/petzvallens.html

Good luck

Dan

[mylek]

So, anything shorter than 8", will give more swirl and longer less.
How it is for Aplanat or RR since they have more coverage?
What will be a good length?
I've a lot to learn...

[C. D. Keth]

So, anything shorter than 8", will give more swirl and longer less.
How it is for Aplanat or RR since they have more coverage?
What will be a good length?
I've a lot to learn...

I think roughly a "normal" length rapid rectilinear is usual for a format. Something like a 6" would be usual for 4x5, but longer could certainly be used or sometimes shorter (perhaps a 4") could be used at small stops.

[CCHarrison]

RR/Aplanats dont swirl. Many Petzval lenses swirl, but only towards the edge of their coverage, so if you want moderate swirl, you need to shoot on a large plate than the lens was designed for (typically). This link should help you http://www.largeformatphotography.info/forum/archive/index.php/t-23190.html

good luck
Dan

[renes]

I agree with that, you should start on 8" if you do not want to have a swirl.