plate size for HBH

[Ty G]

For those of you who have half plate Holmes Booth Haydens lenses, what it the diameter of the barrel? And, will a half plate lens vinette or slightly cut off the corners of half plate at infinity. At portrait distances, covers half plate great.

[Petzval Paul]

The question that arises is "what exactly constitutes a half-plate lens?" In the 19th century, Petzval portrait lenses were generally much longer FL's than we are using today. IOW, the 11 1/2" HBH that I sold on this forum a few weeks back, would have been considered a half-plate lens in 1860. Nowadays, we would often use it on a whole-plate, where did vignette slightly at infinity - most likely due to the very long lens-shade on that model. The early bell-shaped hoods maybe would cause less???? It darkened a bit on the edges, but didn't get a complete "key-stone" effect.

As many of us now consider an 8" lens appropriate for half-plates, things change, of course. I would venture that it might get a bit funky at infinity but I can't say for sure. I bet an HBH would look just amazing on of your sliding box cameras!

[Ty G]

Hey Paul, are you back from India? Thanks for the info. I shot some half plates today, and noticed that when viewing through the ground glass at infinity, the corners were vinetted off and black; yet when I developed the plate there was no vinetting or black curvature. The F.L. of my new lens is roughly 7"-8" to where the radial drive is.

[Petzval Paul]

Ty,

Yeah, got back about a month ago and am "home" for the summer. I would not be the least bit surprised if an 8" lens would vignette on a 1/2 plate. Check this link for some idea:

http://www.luminous-lint.com/app/photographer/Will__Dunniway/C/

If these lenses (I'd guess that they should be around the 8" FL mark by looking) would vignette on a 5x7 at portrait distances, then at infinity it wouldn't be surprising if they vignette on a 1/2 plate.

I use a Darlot 8 and 1/2" for 1/2 plates but never shot at infinity. If I did, I'd probably stop-down quite a bit (if possible - an HBH may not be cut for stops or you just may not have some) or unscrew the rear element and replace it with the front, then stop down to get a more even illumination of the plate. A quick and cheap landscape lens!

It goes w/o saying that you have to make sure that the rear elements are correctly placed, too. I've seen HBH's, Harrisons, Hermagis, etc. that had them set incorrectly and you get that blurred edge effect which also may not help the vignetting.

I know a lot of your cameras will be there, but are you coming to John's jamboree? I just booked my ticket to NY and ma very excited. It was an amazing experience last year and everybody was so wonderful that I couldn't think of not going again and again.

- Paul

[Petzval Paul]

I just looked again and maybe the HBH is around a 6". In any case, not to far off from yours. BTW, if you come across any juicy 1/6 to 1/2 plate HBH's you don't need, keep me in mind! I sold off all of my big lenses since I really don't shoot Petzvals on whole-plates. Wetplate is daunting enough w/o giant lenses, extreme bellows extensions, heavy cameras and darkboxes, tripods, silver baths, etc.! I am liking the smaller plates more these days :-)

[Ty G]

Hey Paul, thanks for the info. I'm tickled to death I finally got an American lens and all I shoot is half plate and smaller.

I will not be able to make it up there to John's this summer. I plan to make it a yearly thing starting the following year. I'll bring up display cameras and such, but at this rate of camera making, there may be a few of mine there this year. I can't wait 'til I can finally make it there to meet all the guys who I am in touch with on a regular basis, yet have never met in person.

Does your 1/2 plate HBH cover 5x7 at portrait distance? I am asking this because I am getting ready to start a camera to go around that lens and have not made up my mind to go 1/2 plate or 5x7.

Have a great day, Ty

[Petzval Paul]

Ty,

You won't regret coming to John's - it's unforgettable! An absolutely amazing bunch of folks up there.

If you are making up a camera with lensboards and bellows, then a 5x7 would be fine since you could always switch out if the lens wasn't doing what you needed. The bellows would make things more flexible for using lenses of different FL's, too. However, at 7-8" FL I would stick with a 1/2 plate if you are making up a sliding box camera. That's just my take it, however, but consider that in the 1860's a 7" lens would most likely have been mounted on a 1/4 plate camera, so 1/2 plate is about as far as you could reasonably go.

[goamules]

Hi Ty, I finally got internet access....been in London and Paris, now I got it in Dublin!

On your question of will an 8" cover 5x7 at portrait distance, it might...barely. And sometimes some vingnetting looks nice, but an 11" would be better.

[Ty G]

Hey Garrett, I decided to just build a half plate camera around it. Unless, of course, you want to get rid of your 11" HBH. "whisper," .....I know you got one.

[Gordon Moat]

The best old (time period) information I have found so far indicates that plate sizes were defined at portrait distances. This is very different than coverage of modern lenses, which is defined for infinity. However, if someone comes across different information from the 1850s era of photography, then I would be happy to include that with the current lens serial number list.

Ciao!

Gordon Moat Photography (http://www.gordonmoat.com)

[goamules]

Sorry Ty, that one is not for sale. One must keep a few, mustn't one?