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View Full Version : Nikkor SW 120/150mm on tapered 8X10 bellows of Sinar Metering back?



Thalmees
17-Jul-2009, 14:35
Thanks in advance for any contribution. This will solve lots of troubles in choosing WA lens for 8X10.
1. Can 120mm Nikkor SW be accommodated on the standard tapered 8X10 bellows of Sinar Metering back, to focus at infinity ?
2. If not; how deep should the recessed lens board to use the same lens with the tapered 8X10 bellows ?
As far as I know the flange focal distance of Nikkor SW 120mm f/8 is 131mm.
3. And what about Nikkor SW 150mm f/8 on the same situation ? FFL ~ 166mm.
4. In another way; what’s the shortest possible focal length that can be used with tapered 8X10 bellows on Sinar Metering back ?
Thanks.

rdenney
17-Jul-2009, 15:47
Thanks in advance for any contribution. This will solve lots of troubles in choosing WA lens for 8X10.
1. Can 120mm Nikkor SW be accommodated on the standard tapered 8X10 bellows of Sinar Metering back, to focus at infinity ?
2. If not; how deep should the recessed lens board to use the same lens with the tapered 8X10 bellows ?
As far as I know the flange focal distance of Nikkor SW 120mm f/8 is 131mm.
3. And what about Nikkor SW 150mm f/8 on the same situation ? FFL ~ 166mm.
4. In another way; whatís the shortest possible focal length that can be used with tapered 8X10 bellows on Sinar Metering back ?
Thanks.

The 120 is marginal for 8x10, it seems to me. The f/22 image circle is rated as 312mm, and it's less at wider apertures, of course.

Looking at the Sinar catalog, the 8x10 tapered bellows appears to have about 25 pleats, which fits with its maximum bellows draw of 25 inches. That will squeeze down to a couple of inches. The 20-pleat 4x5 bellows, which is not tapered and therefore won't stack as tightly, will squeeze easily down to about 1-1/2 inches. The tapered bellows should accommodate the 120 without issue, except that the bellows might not allow shifting. But you won't be able to shift that lens anyway.

The ratings provided by Sinar assume that you'll be wanting to use their behind-the-lens shutter, a metering back, and camera movements. Those ratings are extremely conservative. I can use lenses MUCH shorter than they show in those ratings without those constraints. The metering back doesn't make that much difference.

You won't need a recessed board. I use a recessed board only for a 47, and even then only to give the bag bellows some room so I don't have to fiddle with the folds.

Rick "in case a wide-angle freak with an 8x10 Sinar doesn't answer more definitively" Denney

Thalmees
17-Jul-2009, 21:46
Thanks so much Rick.
I also did some calculations of the minimal practical Flange Focal Length based on very scanty information(some are not 100% accurate). Sorry I forget to add it to the first post.
* The depth of the front standard is around 16mm(by measurement).
* The minimum bellows Ext of the tapered 8X10 bellows is 50mm according to sinar catalog.
* The rest of the distance(the depth of Carrier Frame & Metering Back till the focal/film plane) should be within a factor of 1.65X of the minimum bellows Ext ~ 82.5mm(estimated based on some images that contains all elements of Sinar 8X10 Format Changing Set with the tapered bellows is in retracted position).
Adding all together: 16mm + 50mm + 82.5mm = 148.5mm.
So, I assumed that the shortest focal length lens that can be accommodated on Sinar tapered 8X10 bellows should have roughly a FFL of 148mm or longer. Then a 1.8cm or deeper recessed lens board should be used to accommodated Nikkor 120mm SW on the Sinar tapered 8X10 bellows.
.....................................................
Did I miss something ? Iíll not argue too much on this estimation.
I did my search in the forum but I failed to find specific information.
Real experience has an ultimate value here.
Waiting your response(Rick) and others to correct me if Iím wrong.
Thanks again Rick.

Clive Gray
18-Jul-2009, 06:39
I've never bothered to the maths ....however I have a P 10X8 heavy duty rear bearer a P2 Metering back conversion set and a long legged F 10X8 front standard I also have a bag bellows however when using the 120SW I find it advantageous to use the standard bellows with the lens and the bag belows with the binocular viewer.

This focuses at Infinity fine and you can tilt and as suggested there really isn't room for shift so thats no loss plus it guarantees that you get the 120SW centered.

I would say hear is the evidence but I haven't developed any film from that set up yet, previously I was using a P rather than P2 frame and P / Norma bag bellows either side.

If I get time later I'll lash it together with a standard P front bearer and check if that makes a difference.

With the 150SW I would expect you would find it next to impossible to shift with the standard bellows.

Thalmees
18-Jul-2009, 08:08
I've never bothered to the maths ....however I have a P 10X8 heavy duty rear bearer a P2 Metering back conversion set and a long legged F 10X8 front standard I also have a bag bellows however when using the 120SW I find it advantageous to use the standard bellows with the lens and the bag belows with the binocular viewer.

This focuses at Infinity fine and you can tilt and as suggested there really isn't room for shift so thats no loss plus it guarantees that you get the 120SW centered.

I would say hear is the evidence but I haven't developed any film from that set up yet, previously I was using a P rather than P2 frame and P / Norma bag bellows either side.

If I get time later I'll lash it together with a standard P front bearer and check if that makes a difference.

With the 150SW I would expect you would find it next to impossible to shift with the standard bellows.

Hi Clive Gray
Appreciate your input.
No need for evidence. Once you were able to focus Nikkor 120mm SW beyond infinity even little, it should mean that the lens can be accommodated perfectly on Sinar 8X10 tapered bellows. Also, it indicate that the minimum extension of the whole setup(in this case your Sinar 8X10 C2 with tapered bellows) should be shorter than 131mm. I know that the Image Circle of this lens is marginal as Rick said(312mm@ f/22).
But what really concerns me now is how hard should I find performing shift of Nikkor SW 150mm on a tapered 8X10 bellows. I could not realize that actually. Could you explain please ?
BTW: Flange Focal Length of Nikkor SW 150mm = 166mm. And its Image Circle = 400mm@ f/22.
For me this should be translated to easier shift/tilt(bellows is not squeezed/retracted too much & there is a plenty room for movements).
Waiting your explanation.
Thanks again.

rdenney
18-Jul-2009, 09:02
* The rest of the distance(the depth of Carrier Frame & Metering Back till the focal/film plane) should be within a factor of 1.65X of the minimum bellows Ext ~ 82.5mm(estimated based on some images that contains all elements of Sinar 8X10 Format Changing Set with the tapered bellows is in retracted position).

I don't really know what that 1.65x factor means. But I suspect your 82.5mm should include the compressed bellows, based on what I see in the pictures and what I know of how Sinar cameras go together.

With the 150, the bellows will be opened up a bit, but stiff pleated bellows don't like the shift movement unless they are opened up quite a bit. Tilting is no problem.

Sinar did make an 8x10 bag bellows, and were I use I'd make do with the tapered bellows, living with limited movements, until a deal on the bag bellows appeared. Changing out bellows on a Sinar in the field is really very easy.

Rick "sure enough that it will work to be worth trying" Denney

Thalmees
18-Jul-2009, 09:45
So, in the case of Nikkor 120mm SW, the limiting factor is the IC. While with Nikkor 150mm SW, the limiting factor is the stiff pleated bellows.
Really grateful Rick. Thanks.

Clive Gray
18-Jul-2009, 13:20
Some dodgy photos

Minimum belows extension
very roughly measured as about 85mm from rear of lens board to film plane marker

http://farm3.static.flickr.com/2596/3733149416_342e354c9e_b.jpg

Extremely approximately set as 165mm

http://farm3.static.flickr.com/2673/3732354125_8575de9530_b.jpg

As above but with 15mm shift and not liking it too much

http://farm4.static.flickr.com/3443/3732357203_8ca4bdf8fc_b.jpg

Bag belows distance the same but with maximum shifts the standards would allow and no problem at all.

http://farm3.static.flickr.com/2485/3732348247_8b938625b7_b.jpg

Different 10X8 bellows might vary in their compressibility certainly the Norma ones I have are more compact that the P era ones I have. The P2 format changing set ones I have appear to be a particularly good set and will compress down to about 25mm.

Hopefully the photos will illustrate the difficulty you might encounter using the standard belows with the 150SW and trying to use shift and demonstrate that the bag belows are a much more satuisfactory option with that lens.

The 120SW is absolutely fine with the standard belows and while the 150SW will work shift wil be very limited.

I am lucky that a friend looks after the Air conditioning of Teamwork Digitail in London and recently asked me to go there to fix a problem .... seeing a P2 there I asked did they ever get the bag bellows in to which the reply was rarely, however while searching for a screw I thought had gone down the stairs to the basement I noticed something of interest in a crate of bits. No charge was made for the Air con and I got a set of not to bad bag belows and every one was happy with the arrangement.

The new list price for them is frankly scary and they only seem to come up secondhand fairly infrequently.

Hope the photos are of some help illustrating the point.

Thalmees
18-Jul-2009, 18:25
Amazing Clive Gray.
Clear, informative, detailed and accurate answer.
This is above what I asked for.
Really great kindness Clive.
Thanks.
Also an excellent reference to anybody contemplating purchasing an extreme wide angle lens.
Best regards.