Graflex.org
Get help with your Graflex questions here

Do it yourself lensboards
Goto page Previous  1, 2
Graflex.org Forum Index -> Lenses Help
AuthorMessage
Capitain Boar
Joined: 20 Mar 2011
Posts: 18
PostPosted: Fri Apr 22, 2011 4:26 pm

Ok, I have just got my camera.
I have adapted my Xenar and Toko Anastigmat lenses for it. I had to cut some metal from the lens fixing nut on my Xenar, so now it fits in Speed's lens mount.
The lensboards were made of 3 mm PVC (64 mm square). I have cut the circle first and then I had cut the lensboard.

The Toko really covers all the 6x9 frame without light fall in the edges. it's not so sharp at the edges and it's pretty sharp in the centre. In th future I want to adapt to my Speed two more "wide angle" lenses: Iskra's Industar 58 (it shows some vignetting on the edges) fn a T-22 from Lubitel.
Xenar is very good and sharp even when it's wide open. I will try it as a portrait lens.
The normal Kodak Anastigmat is a good lens too. Unfortunately I don't have working Compur or Moment shutters (rear component on Industar has a slightly wider thread like on Bessa or Super Ikonta, so it doesn't fit most shutters of this type).

My Speed is not very good, but it works well. The rangefinder needs a new mirror and a metal pusher to couple it with the carriage. I have removed the whole rangefinder indefinitely till I will find or make these parts.
The focal plane shutter is working good at all speeds, but it is very loud.

I have purchased a Busch Pressman Model C modified for the Graflok to use it like a field camera. Is the normal 3,5/100 coated tessar in Synchro Compur suitable for all the movements of the camera? Probably Xenar would be a better lens for it... Can I make lensboards for Busch as easy as for Graflex?
1banjo
Joined: 16 Nov 2008
Posts: 492
PostPosted: Fri Apr 22, 2011 11:48 pm

mey on the busch if it is a 4 screw or not it can be made out some thing like 5mm flat sheet Aluminum needs to be 60mm sq.
I use 2 peaces of it 1 peace is 60mm x 60mm
the other is for the inside and it needs to be 51mmx51mm
the 4 screws holes are 3mm
I have found the you can use the 4 screw lens board on the newer quickchange camera as it still has the 4 screw holes you only need to use the top 2 screws
I screw the 2 peaces togher

but to make the quickchange lens board you need to make a 90* bend in
it
but you don't have to use Aluminum youcould use ABS too

banjo
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sat Apr 23, 2011 4:45 am

Quote:
Is the normal 3,5/100 coated tessar in Synchro Compur suitable for all the movements of the camera?

Normal? Standard? Which lens does the camera have? 101mm seem to be the standard but most common would be a more accurate term. Searching the web for 100mm f3.5 tessar lens I did not find much nor did I find much information on a Busch Pressman C.

From: http://dbsi.org/~david/pentax/attic/large%20format%20camera%20film%20holder%20specifications.htm
we find the exposure dimensions of a 2x3 film holder to be 2.163 inches x 3.338 inches. Now we find the diagonal by the formula A squared + B squared = C squared, so: 2.163 square=4.678569 + 11.142244 = 15.820813. Taking the square root of that sum we get 3.9775 inches. Multiplying that by 25.4, the number of mm per inch we get 101mm.
Any lens that has a minimum of 101mm of coverage will just cover the 2x3 format with NO movement. A lens with more than 101mm of coverage will have some movement available.

Looking at http://graflex.org/lenses/lens-spec.html , Schnider Xenar 100mm f3.5 has 117mm of image circle so it will have 16mm of image circle wiggle room for movements.

calculation in mm:
2.163(inch)*25.4(millimeters per inch)=54.9402(mm); 54.9402*54.9402=3018.42557604
3.338(inch)*25.4(millimeters per inch)=84.7852(mm); 84.7852*84.7852=7188.53013904

3018.42557604+7188.53013904=10206.95571508
square root of 10206.95571508=101.02947943585575062714994623126mm
Henry
Joined: 09 May 2001
Posts: 1662
PostPosted: Sat Apr 23, 2011 2:32 pm

45PSS wrote:

Any lens that has a minimum of 101mm of coverage will just cover the 2x3 format with NO movement. A lens with more than 101mm of coverage will have some movement available.

Well, math formulae notwithstanding, the 101 Optar on my Century covers 6x7 without vignetting and with full front rise. Don't know about 6x9, tho.
Capitain Boar
Joined: 20 Mar 2011
Posts: 18
PostPosted: Sat Apr 23, 2011 4:04 pm

45PSS
My Busch has a Tessar like this:

Someone says it can cover a 130 mm circle, so I have at least 10 mm for shift or 15 mm for rise and fall.

But, I think, it is not enough for all full movements. I think I must adapt a Xenar for my Busch.

Also I would like to know maximum movements of Busch Model C:
Tilt......... (degrees)
Bed drop -----||----
Rise....... (mm)
Fall........ --||--
Shift...... --||--
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sat Apr 23, 2011 6:46 pm

http://www.cameraeccentric.com/html/info/graflex_19.html
gives some information on the Zeiss 100mm f3.5 Tessar but no image circle information, only angles of view.

I doubt you will ever need to use the maximum movement of the camera. A compact lens designed for a larger format can be used on smaller formats and give you more movement potential.


The image circle projected by a lens is not the same as the lens focal length even when the numbers are the same. 101mm focal length is not the same as 101mm image circle. Both are types of measurements of lens.
Henry
Joined: 09 May 2001
Posts: 1662
PostPosted: Sat Apr 23, 2011 6:53 pm

Sorry, I misinterpreted your previous post!
1banjo
Joined: 16 Nov 2008
Posts: 492
PostPosted: Sat Apr 23, 2011 9:18 pm

Also you would like to know maximum movements of Busch Model C:


Tilt......... (degrees) 25* back only
Bed drop -----||---- 30*
Rise....... (mm) 95mm to 127mm
Fall........ --||-- NA
Shift...... --||-- 12mm each way

this is what I get on one of mine

Banjo
45PSS
Joined: 28 Sep 2001
Posts: 4081
PostPosted: Sat Apr 23, 2011 9:27 pm

I kinda thought that second cup of coffee hadn't kicked in yet. :D
Capitain Boar
Joined: 20 Mar 2011
Posts: 18
PostPosted: Sun May 15, 2011 8:42 am

1banjo wrote:

Tilt......... (degrees) 25* back only
Bed drop -----||---- 30*
Rise....... (mm) 95mm to 127mm
Fall........ --||-- NA
Shift...... --||-- 12mm each way
Thank you, Banjo! But mine does not have shift.
Tessar is great! I think I don't need any other lenses for my Busch.
1banjo
Joined: 16 Nov 2008
Posts: 492
PostPosted: Sun May 15, 2011 9:52 pm

for side to side shift just push it one way or the other
it has NO locks
Capitain Boar
Joined: 20 Mar 2011
Posts: 18
PostPosted: Fri Jun 03, 2011 3:28 pm

It works!
Thank you!
All times are GMTGoto page Previous  1, 2