Will Extreme Stretching of Bellows Effect Sharpness?

[bakerbang]

Hello,

I am using a Sinar P for Macro work. The Bellows extension is just over 1000 mm using two bellows and 3 Standards.

One of the bellows is slightly older than the other and is incredibly stretched to reach the required distance. Focusing is extremely difficult even with several extra redheads on the subject just for focusing.

My question is because of the bellows being over stretched is it possible it's making focusing difficult and effecting overall sharpness on the final image? I appreciate there are a number of possibilities that could make an image soft but let's imagine I have spent weeks eliminating them!

Thank you
www.jon-baker.co.uk (http://www.jon-baker.co.uk)

[David A. Goldfarb]

At max extension I'd just be concerned that the front standard might be flexed out of parallel, even on a Sinar P, but you can look at the bubble levels to confirm that.

[Ken Lee]

I shoot macro with a Sinar P. Keep in mind that the focusing mechanisms don't have locks. They are very sturdy but I have noticed that if I point the camera straight down with a heavy lens on the front standard, some focus shift is possible. It happens slowly, while you are loading the film and making the shot.

One recommendation would be to use a shorter lens. At macro distances, even a modest decrease in focal length translates to a large savings of bellows draw.

For example at 1:1 a 250mm lens requires 500mm bellows draw. A 200mm lens requires only 400mm of draw, a savings of 100mm or 4 inches: enough to make the difference between comfort and... agony :rolleyes:

Another suggestion is to shoot in horizontal orientation.

[Bob Salomon]

,
I shoot macro with a Sinar P. Keep in mind that the focusing mechanisms don't have locks. They are very sturdy but I have noticed that if I point the camera straight down with a heavy lens on the front standard, some focus shift is possible. It happens slowly, while you are loading the film and making the shot.

One recommendation would be to use a shorter lens. At macro distances, even a modest decrease in focal length translates to a large savings of bellows draw.

For example at 1:1 a 250mm lens requires 500mm bellows draw. A 200mm lens requires only 400mm of draw, a savings of 100mm or 4 inches: enough to make the difference between comfort and... agony :rolleyes:

Another suggestion is to shoot in horizontal orientation.

Or add an aux. standard and another bellows, and maybe rail.

[Ken Lee]

If you need to shoot downwards onto a table, you can use a mirror at a 45 degree angle: this will keep the camera level.

Another option - from the old days - is to use a reversing prism. See this old Goerz catalog on cameraeccentric.org (http://www.cameraeccentric.com/html/info/goerz_3.html), page 26.

[DKirk]

What is it you're photographing? As a while back we were using a Sinar (part Norma, Part F) set up for photomicrography (Top floor of the Glasgow College of Building and Printing) - one factor that affected sharpness was the trains on the Queen Street low-level line. . .

[Jim Noel]

If a bellows is extended to the point of smoothing out the pleats it defeats one of the purposes of a bellows - elimination of most internal reflections. This may make focusing difficult, and it will result in no-image forming light, or fog, and less contrast in the negative.

[Doremus Scudder]

... and, if your bellows is stretched too tight it can pull the standards out of alignment and even pull the focus back shorter (reverse focus creep) in the time it takes to insert the filmholder, pull the slide and make the exposure. I second the idea of using a shorter lens. You'll likely get better results that way anyway.

Doremus

[bakerbang]

Wow thank you everyone for your advice it's been very helpful. I have taken apart the camera and had a good look at everything, there is slight movement in the bellows if the camera is pointed down, something I haven't noticed before. I think investment in another standard and another bellows will be helpful as when they are maxed out focusing is almost impossible.

Another lens is also a possibility, at the moment I am using a schneider 150mm any advice as to what would be a good replacement lens in this situation
maybe a dedicated Macro?

Thank you
Jon

[bakerbang]

What is it you're photographing? As a while back we were using a Sinar (part Norma, Part F) set up for photomicrography (Top floor of the Glasgow College of Building and Printing) - one factor that affected sharpness was the trains on the Queen Street low-level line. . .

Hi DKirk I am photographing succulents and other plants then cross processing the film. I am making the images on a poured concrete floor in a basement with a very large tripod.

I would be very interested to see the images from your photomicrography experiments,

best

Jon

[Bob Salomon]

Wow thank you everyone for your advice it's been very helpful. I have taken apart the camera and had a good look at everything, there is slight movement in the bellows if the camera is pointed down, something I haven't noticed before. I think investment in another standard and another bellows will be helpful as when they are maxed out focusing is almost impossible.

Another lens is also a possibility, at the moment I am using a schneider 150mm any advice as to what would be a good replacement lens in this situation
maybe a dedicated Macro?

Thank you
Jon

You would get much better results and eliminate your problem with a true macro lens like the 120mm Apo Macro Sironar.

[Ken Lee]

You would get much better results and eliminate your problem with a true macro lens like the 120mm Apo Macro Sironar.

What Bob said !

Given the size of the prints on your web site and the corresponding effort and expense, using a non-macro lens for this purpose is inconsistent at best. I've used that lens and it's truly superb.

[Dan Fromm]

I think investment in another standard and another bellows will be helpful as when they are maxed out focusing is almost impossible.

Another lens is also a possibility, at the moment I am using a schneider 150mm any advice as to what would be a good replacement lens in this situation
maybe a dedicated Macro?

Hmm. It seems that you're focusing by moving a standard, most probably the rear. This changes the magnification. Real people select magnification by setting and locking extension, then focus by moving the camera/lens assembly or the subject. Consider doing that.

With a 150 mm lens and 1000 mm of extension you're shooting at around 5.67:1. You'd do well to use a shorter macro lens. 55/2.8 AI/AIS Macro Nikkors are abundant, inexpensive and will easily cover 4x5 at that magnification. Reverse the lens, hang it in front of a #1. SKGrimes will make an adapter to do this (M52x0.75 at the lens end, M40x0.75 at the shutter end) for not much money.

You don't seem to know much about photomacrography. Lester Lefkowitz' book The Manual of Closeup Photography is a good introduction. Used copies are available for little money from vendors who sell through, in alphabetical order, abebooks.com, alibris.com, amazon.com, ....

[Sal Santamaura]

...Real people select magnification by...Do you think the OP's a bot rather than a "real person?"

Way to welcome a new member. :(

[Dan Fromm]

Well, Sal, the OP sets up a camera like a bot.

Amend "real people" to read "people skilled in the art."

Cheers,

Dan

[bakerbang]

you got me I am not a real person but an AI created by Google and sent out into the world to test my humanity. On the side even though I knew nothing about it I thought I would try some photomacrography. Turns out I am pretty good at it, although that Lester Lefkowitz book looks good and I have ordered it.

Unfortunately I won't be able to read it as I have failed the humanity test and Google is wiping my humanity drive.
Rumbled by Dan Fromm......................

[Dan Fromm]

bakerbang, its wonderful that you think you're good at photomacrography. Shortly after my first excursion into photomacrography I formed much the same impression of my work. Boy, was I mistaken. I hope you started better than I did.

Errare humanum est.

[aluncrockford]

You might well find that reversing the lens will help, the length of the bellows extension has no relevance to sharpness. if you are using flash then use the open shutter technique ,that should sort out any movement issues and also get around the problem of firing the lens when its reversed

[Bob Salomon]

You might well find that reversing the lens will help, the length of the bellows extension has no relevance to sharpness. if you are using flash then use the open shutter technique ,that should sort out any movement issues and also get around the problem of firing the lens when its reversed

If the bellows isn't extended enough, or if it is extended too far, then you will be out of focus so bellows extension is very relevant to sharpness.

[tgtaylor]

One thing for certain: Extreme stretching of the bellows will lead to pin holes/tears in the corners.

Thomas

[Cor]

Perhaps consider a top quality enlarger lens, 80mm (say a Schneider Kreuznach Componon S (perhaps the APO version) 80mm ) reverse mounted, assuming that the exposures are in the seconds range so you can use your hat as a shutter..

good luck,

Cor

[bakerbang]

Perhaps consider a top quality enlarger lens, 80mm (say a Schneider Kreuznach Componon S (perhaps the APO version) 80mm ) reverse mounted, assuming that the exposures are in the seconds range so you can use your hat as a shutter..

good luck,

Cor

The exposure is definitely in the seconds range. How would this enlarger lens compare with a 120mm Apo Macro Sironar lens? I am hiring the macro this weekend to see the quality and if it reduces my bellows length, but I would be interested to see how the enlarger lens works

Best

Jon

[Bob Salomon]

The exposure is definitely in the seconds range. How would this enlarger lens compare with a 120mm Apo Macro Sironar lens? I am hiring the macro this weekend to see the quality and if it reduces my bellows length, but I would be interested to see how the enlarger lens works

Best

Jon

It won't, and it usually will require your finding a shutter and an adapter ring to reverse it and another to mount it. It's best use would be for flat copy work like duplicating slides. But then a true duping lens would be even better. From Rodenstock those are the Apo Sironar-N lenses and from Schneider they were the M-Componon series. But those lenses also would require a shutter. For your use the Apo Macro Sironar would be much better and it comes in a shutter!

[bakerbang]

It won't, and it usually will require your finding a shutter and an adapter ring to reverse it and another to mount it. It's best use would be for flat copy work like duplicating slides. But then a true duping lens would be even better. From Rodenstock those are the Apo Sironar-N lenses and from Schneider they were the M-Componon series. But those lenses also would require a shutter. For your use the Apo Macro Sironar would be much better and it comes in a shutter!

Ok good advice I will let you know next week how it goes

[Cor]

I have no idea, Bob apparently has, but money wise it was a no brainier for me since I had the lens already in my enlarger.I tried it on my 8*10, exposed on lith film and was pleased with the resulting contact print. Surely you know that DOF is non-existant. Oh I simply taped the lens with its enlarger mounting ring on a lens board, and used a black piece of cardboard as a shutter, my exposures were sometimes in the minutes range, had to convince my family members not to move, I use the dining table in the living room as my table top....;-)...

Good luck,

Cor


The exposure is definitely in the seconds range. How would this enlarger lens compare with a 120mm Apo Macro Sironar lens? I am hiring the macro this weekend to see the quality and if it reduces my bellows length, but I would be interested to see how the enlarger lens works

Best

Jon

[Bernice Loui]

Far better to add an additional front standard and bellows as needed. Keep adding these as required. What will be come a significant problem with increasing bellows length, added rail length and overall camera length is stability relative to the subject. Keep in mind the long camera balancing on essentially a fulcrum-piviot aggravates this problem regardless of how big or apparently stable the tripod might be.

*Using a reverse mounted enlarging lens works. Image circle increases as the reproduction ratios near 1:1 allowing the using shorter than normal focal lengths that can and will significantly reduce bellows and camera length overall. Or, use a macro specific lens. Other lens possibilities are microscope objectives. Shutter requirements can be a significant limitation to using alternative lenses.

*Figure in exposure loss with increasing bellows draw and reproduction ratios. Figure aprox about two f-stops less at 1:1. Consider film speed-sensitivity loss with reduced light and exposure times.

*Any camera movement or subject movement will result in blur.

*DOF can become a problem, Know only the small area that is focused on is going to be the only small area that will be in focus unless the subject is absolutely flat. Stopping down the aperture alone might not cure this effect.

*Consider mounting small subjects on the spare front Sinar front standard with a lens board. This effectively turns the Sinar into a copy camera with a small copy board. This goes a long ways to keeping movement between subject and camera under control as the camera-subject tends to move together as a unit rather than separate items.


Bernice

[aluncrockford]

I had made the mistake of assuming the image was focused,and the sharpness of the image was the problem and not an issue of compedence, It is good to realise that despite working as an advertising photographer for the last 30 years I know nothing, and my advice is worthless, it is not a mistake I shall make again.

[LabRat]

If you are using fairly low wattage hot lights, you can also use an enlarging timer to control exposure... Open the shutter (or pull the slide) in the dark, sit down and relax (move VERY little), let the rig settle (for a while), hit the timer (or timer remote), expose, and recap film...

Check what your timer says about the max wattage it can handle... For higher wattage lights, you can buy a heavy duty relay from an electrical supply store, and wire it so when the timer outlet is powered, it operates just the relay, and it's contacts close the circuit for the lights that are plugged into another outlet...

Steve K