rob_hale1

November 16, 2013

Hi Bruno, As you are “starting” and presumably don’t have enlargers etc. may I suggest :- “Knowing what I know now” I would go 5 x 7 as it is the smallest but practical size to contact print. I would develop in pyro/pyrocat hd using besseler tube and print on Lodima/Azo. Later when I am comfortable I would look to going up to 11 x 14 again contact printing. This may seem expensive but it is not really when you take into account all the big dark room gear. The above of course, presumes that you going to do B&W printing not colour. Regards Rob

June 10, 2013

Hi Jos.

First, I am glad that your negs. looking better.

Yes "link" that's the sort of information from P.E.

I am not aware of any film roller transport systems that pre wet before dev. I shudder to think of the millions of miles of film that has been developed in roller transport machines world wide.

You can stick with what is working knowing that "dry pre dev warming" is there in the background, if you have problems. You could use a "Macbeth ColorChart Checker" to check that you getting the full range of contrast and colour ( we should all probably do this more often ).

Regards

Rob

June 9, 2013

Hi Jos, Yes Jobo drums are a pain to dry. I put mine out in the sun on a towel to dry ( I have extra drums so I can rotate drums ). Re “Pre warming”. C41 is a multi layered film which uses a controlled temperature specific diffusion process to develop the different coluors in the correct order. Pre wetting the film is likely to upset the diffusion rates. Do a search on this; there is good information from industry qualified people available at APUG I think. Regards Rob

June 8, 2013

Hi All,

Humm, Jobo's instructions are "Pre warm" for 5 minutes "DRY" not wet.

Regards

Rob

February 3, 2012

Hi Guys, Umm, contact prints. I have yet to meet some who has not been impressed by well made contact prints 4 x 5, 5 x 7, 8 x 10, 11 x 14 above this size the camera lenses “seem” to loose a little something, still very impressive. Part of the answer can be found in the research done by Ctein and can read in his book “Post exposure” second edition Focal Press ISBN 0-240-80437-6, if you have not read this book perhaps you should.

Also remember a lot of papers have at least 60 lpm resolving power, so when you put another lenses in process chain, in an enlarger – no matter how good the lenses “you will loose print quality”. Humm, the enlarger can be considered to be a device of convince that allows photographers to carry small cameras by sacrificing the print quality. It made mass photography commercially viable thus allowing “every one” to make pictures and so creating an enormous demand for film, chemistry, cameras and lenses, labs to process film, a demand for papers and associated chemistry, toners etc and for printing. Thankfully, so, we, you and I now have the options to print stunning contact prints up to 11 x 14 and some pretty impressive stuff up what is 20 x 24 ? and also print from small handy cameras up to a commercially acceptable standard. Regards Rob

October 21, 2011

Hi Ryan, Humm

Hyperfocal distance. One of the joys of LF is the GG and being able to see what is happening as one focuses, “what you sees is what you gets”

I my humble experience there 5 things about the “plane of focus” that I have found :-

1./ Any lens has an F stop that it will give you best / sharpest focus, outside that particular F stop the focus available becomes a level of un-sharpness that is acceptable. 2./ That the sharpest focus / sharpest contrast will be better / tighter / edgyer in front of the plane of sharp focus – towards the lens than behind the plane of sharp focus. 3./ That no two lens ( except perhaps the most modern ) are the same in what and how they focus. 4./ Most of the time, when we are focusing we are working to the level of “acceptable” focus. 5./ I have yet to see a hyperfocal distance picture that I considered to be “in focus”.

So basically if you want infinity in sharp focus “ then focus on infinity ”. Infinity in this case being that which is at the greatest distance from the lens.

To answer the question as asked what is the distance that is “infinity” well that depends on how the lens is optimized but for most lenses you will be close to infinity when say you focus at 100 meters sharp focus if you then change the distance to 200 meters and the GG only has to move 1 or 2 mm. If you now focus on the moon there is usually an other shift.

Have fun, use your GG and a good 10x or more loupe.

Best Regards Rob

P.S. Using the depth of field scales on MF lenses will not give accurate results as the C.O.C. used to calculate these scales was / is stunning large. R

October 17, 2011

Hi

Artist considerations… Humm

If you can’t mix the colour you want no number of Artist considerations matter as the painting will be ugly. If you can’t sharpen a chisel you won’t achieve a carving no matter how good your Artist considerations are.

There are no “silver bullets” only bad tools, good tools and better tools and practice, practice and more practice, then when you see what you want you have the ability to make the picture.

Now don’t get me wrong we all need to “see” and “learn” what and how the history of painting, sculpture, architecture and photography have produced master pieces that have and are standing the test of time. So visiting art museums will broaden our knowledge and understanding.

Regards

Rob

October 14, 2011

Hi Kris,

You have a lot “stuff” here.

Light meters. There are some people who can judge light to a degree, whether that level of judgement is acceptable in a practical sense is a personal choice.

Light meters and large format lens shutters co-relate as very few of the shutters we use are as accurate as our M/F shutters so most of us have the learn which shutter is doing what; which is why most the successful L F users keep notes.

Pre and early light meter L F photographers tended to develop by inspection which some and E. Weston would be an example, got very good at. Also the triple convertible lens had the great advantage of only having one shutter to learn. Adams used Polaroids a lot to find the exposure that he liked.

In the end you can take a short cut to really good prints by buying a good spot meter and learning how to use it and being aware that older shutters vary the time that they are open so start off by keeping to one or two shutters until you have confidence in your routine from shot to print toning. As an indication my Minolta VI cost more than any other single L F item.

Have fun.

Regards

Rob

September 8, 2011

Hi Graham, This question came up in a similar form on another site to which I suggested the following possible solution, which might also suit you :- http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=4483&page=2 the Rob Hale post on this page that is addressed to Andy. If it suits you, there is a whole new arena of classical printing without the need of a full blown dark room, enlarger and enlarger meters etc, etc. Regards Rob

July 18, 2011

Hi Blake F.

"I am 23 and I have not been to an eye doctor in at least 5 years but I know I have an astigmatism so maybe that is the problem?”

Me too, astigmatism. I can see the fine twigs at the top of a tall gum tree 200 meters away without my glasses. I have long range glasses and medium to reading range glasses. I have had glasses since I was 12, the optician said I did not need them !! Guess what, my written maths, which I constantly got wrong suddenly improved to the same standard as my oral question maths.

Personally I won’t go without my glasses they make everything much much easier too achieve.

I have noticed that LF GG work with the short – medium range give excellent focus. For MF the diopter of the focusing screen can stuff up the focusing if it does not match the glasses in question.

I have also found that not all opticians under stand that what I have is correctable, I am in my latter years and have moved a number of times to places out reach of my last good optician so have had “try out” to find someone who is actually good. In my case I can see that the newly proposed lenses are better than the ones being replaced.

Sorry to go like this but if you get the correct lenses I am sure you will hate to be without them. I can not understand these fashion conscious people who won’t wear their glasses and go around in some kind of gray mist instead of seeing the world in crisp, clear contrast – nuts, it’s a beautiful world if you can see it clearly.

Best Regards Rob

July 16, 2011

Hi Chris,

Buy T R's toning book direct from him.

Regards

Rob

July 14, 2011

Hi For B&W two very important books “Way Beyond Monochrome” Fountain Press and “Controls in Black and White Photography” by Richard Henry this one you will need to source second hand. After those two think about getting a copy of Tim Rudman’s Toning which has been reprinted ( it reached remarkable second hand values while it was out of print ) and keep your eyes open for a copy of “The Keepers of Light” by W Crawford a lot of excellent historical stuff on a range of processes with pictures. Of course you could simplify things by going straight to contact printing with pyro negs. and getting a copy of “The Book of Pyro and PMK Formula” by Gordon Hutchings and printing on AZO. Google “ azo michael a smith ” for info on Azo. This saves all the buying of enlargers and enlarger lenses etc. and being contact printing a modest lf camera lens will print out remarkably well. Regards Rob

May 25, 2011

Hi Francesco, Humm, I second Danny’s advice. Find a good machine shop and get them to “bore” a hole to match the size of you shutter. I don’t know where you live but in most places the cost of 34 – 35 mm drill will be hugely more than the cost of 10 – 15 minutes of machine time. Also the hole can be matched in size to the shutter. A drill will be the size it is and that may not the correct size for your shutter. It gets worse when drilling thin sheet metal, if the drill bit diameter is any bigger than the thickness of the sheet metal being drilled ( or there abouts ) you need a special drill bit and that adds to the cost again. Best Regards Rob

May 21, 2011

Hi Francesco. All the above is only nearly “Good Stuff”. All these formulae are based around COC and in some cases algebra, which frankly does not work. I normally work with large format or medium format where I can check the focus and focus quality. Then I bought a Mamiya 7, as it is a range finder I had to “understand” the focus and depth of field. None of the “calculators” or formulae work to a level that I found satisfactory so I my advise is “beg, borrow or hire” an 8 x 10 camera. Mount YOUR lens and do tests to find just what your lens will give you for the work you what do. You may find that your personal “just acceptable” sharpness of DOF is much further away from your film than the calculations tell you, trust me, it is much better to know this before you build than to be disappointed after you have built. Also you won’t need to find things like nodal points of your lens because you can measure the actual distances ( I would suggest that you buy your self a quality stainless steel rule, probably 24” - 600 mm ). Have fun and let us know how get on. Best Regards Rob

February 18, 2011

Hi Paul Late in coming to this thread – via looking for volumes of PMK to area of film. Your picture “ Same roll different shot “ was this taken with a Pin Hole camera ? If so what are the dimensions – pin hole size – pin hole to film – film size ? Very nice picture. Regards Rob

January 12, 2011

Hi Tri & Jim. The very best for a successful show, unfortunately impending grand child’s arrival prohibits a quick trip up from N Z. Best Regards Rob

November 23, 2010

Hi Wieslaw Know what, I think the film has been damp or wet at the edges, possibly for quite a long time. Best Regards Rob

June 10, 2010

Hi Jay. Umm due to your question I thought I should reassess this adjustment and decide if I should send it off for repair as mine is very stiff. Well, try this, instead of using your finger, turn the camera round so the lens is facing you. Left hand behind the body. Use your right hand thumb to press the button in and to rotate the hub. Well all of a sudden mine is smooth to rotate and easy to use. Hope your responds to this method. Best Regards Rob

May 15, 2010

Hi Edward, Humm dish washing liquid, do you mean hand dish washing liquid if so, not good for any thing you do not want to have smears of glycerine on. Most hand dish washing liquids have glycerine to protect the dish washers hands. Regards Rob

March 22, 2010

Hi Norman,

First things first. Unless you are like David and have spent a lot of time taking delicate mechanisms to pieces and repairing then trend carefully when following David’s plan. Have you tried one of those arthritis "Boa Constrictor" jar lid removers. They have a rubber strap and handle through which the rubber strap passes so that it can be tightened around the jar top as you unscrew or in your case the filter. These are very similar to one of the many car oil filter remover desgins. You can get them from Lakeland in England, who have a web page. I have never had a filter or LF lens elements that have not responded to this device.

Secondly.Adrian's suggestion can be extended by marking out a ruler on the surface and a focal point. Then you will know which way and how much the focus out. You can also use it to check DOF.

Regards

Rob

March 15, 2010

Hi David,

I don't think we have talked yet, I would appreciate a copy of the RZ manual you have. I am rhale@hale.co.nz.

Hi Troy,

First, your RZ should fire the shutter system without a back on, with a lens on if the lever is in the multi postion. The lens shutter spring should be cocked before the lens is mounted.

To clean the button shaped contacts I have found an artist’s eraser is best, just don't let the dross get in to anything. The pin shaped ones you should use contact cleaner on a cotton bud, don't spray contact clean on the pins it will go where it will not do good. While cleaning check that battery compartment is clean. There's point you do have the battery in the right way round ?

Now be aware that the shutter up cable on connector on the lens needs to be all the way in when not in use. So that the red band is either out sight or very nearly so also the boss should lie in the middle of it's hole not tipped over. If the connector is not fully home, you will need to mount a release cable to bring it out. You can use any standard cable in this connector, once you have the connector fully out you should be able unscrew the cable to let the connector return home. This may be the source you problems, as weird things happen if the connect is not seated correctly.

Regards Rob

March 12, 2010

Hi Brian,

I have no problem with your discomfort with maths and numbers. The difficulty I see is how to get your extensions sorted.

I will take a punt and guess that your 150 lens is not a tele focus or something unusual.

Buy yourself a small steel tape measure. With a felt tip marker pen black out from zero to 150 mm. At 187 mm draw a stripe across the tape with marker pen and next to it put a small sticky label with “ .5 f “ on it. At 225 mm draw the stripe and put a small sticky label with “ 1 f “ on it. At 262 mm draw the line and label “ 1.5 f “ At 300 mm draw the line and label “ 2 f “ At 337 mm draw the line and label “ 2.5 f “ At 375 mm draw the line and label “ 3 f “ At 412 mm draw the line and label “ 3.5 or 4 f “ At 450 mm draw the line and label “ 4.5 f “

To use.

Compose your picture, dof, lighting etc. Take light reading and set the shutter to match. Now take your newly marked out tape and measure from the lens board to the film plane. If the distance is equal to or greater than any of the mark points on the tape use the number on the label next to the marked point. If the number is a whole number, slow the shutter down by that number of stops. If the number has a part number, open your aperture by that decimal.

Example: 1/ The distance is 310 mm which equals 2 f, because 310 mm is in between 300 mm and 337 mm. The shutter is set on 1/125 so you slow the shutter down 1 stop to 1/60 then a second stop 1/30.

2/ In this example I have dropped the fractional time notation. The distance is 345 which equals 2.5 f. The shutter is set on 30 and the aperture is f 16. So you slow shutter down 1 stop to 15 then the second stop to 8 now we now open the aperture by .5 f stop so you move the from 16 to 11.5. If it had been set at 16.5 you would move it to 16.

There is a very nice analogue light meter with a disk system of read out which allows one to see all this information at once. The f stops and time side by side far simpler to comprehend than digital systems. These are the Gossen Lunasix F, the Profisix sbc and all of the 9 volt battery ones.

OK give this a try and remember that your shutter is anything up to plus or minus 30% so do test with film.

P.S. in the previous post there is a typo in the list of numbers 2.25 should read 2.5.

Regards Rob.

March 12, 2010

Hi Denis,

My Pro 11 backs will release and receive the film cassette without taking the body of the back off the camera, it will also release and receive the back without the film cassette. So the film cassette, should in theory, not be causing a problem.

These backs need to be lined up very close to exactly correct for the pins/buttons on the camera body. This you should find simpler to practice with the camera body on your knees with lens facing down. Better yet have the camera body at eye level, lens pointing down, resting on a table so you can see what you are doing rather than having to feel. You should have a friend hold the camera and lens steady while you look at what you doing. What I am saying is that I do not think there is anything wrong with back or the body.

I do not have the RZ here with me so I can not check this but it is possible that if the R-M lever is not pointing up at the dot and is pointing to M or R the back will not go on. Perhaps someone who has an RZ to hand could check this and let Denis know.

Regards Rob.

March 6, 2010

Hi Brian,

Allow me to simplify, in practical terms, the Inverse square law when applied to the shutter factor for Bellows Extension.

The law states that :- shutter factor = (bellows extension) squared / (focal length) squared

This calls for the focal length of the lens, as written on the lens, to be the same as the distance between the lens and the film plane when focused at infinity. Unfortunately this is not always the case, so I will introduce “infinity focus length”. This is a “Practical” measurement of the distance between the lens board and the film plane when focused at infinity. This saves getting involved with nodal points etc when they (nodal points etc.) do not make a substantive difference.

1/ now we have, shutter factor = (bellows extension) squared divided by (infinity focus length) squared

2/ shutter factor divided by 2 = f stop adjustment (or stop adjustment) where ‘f stop adjustment’ or ‘stop adjustment’ is the extra light required.

3/ the bellows extension of any lens is proportional to its infinity focus length, thus you only need one set of shutter factors or f stops, or parts thereof, for all your lenses.

For any extension minus the infinity focus length that equals 0.25 of the infinity focus length, or increments of one quarter (eg. half, three-quarters, one etc), the following list shows the f stop/s you open the aperture by.

0.5, 1, 1.5 , 2, 2.25, 3, 3.5 or 4, 4.5, 5, 6, 7, 8

For shutter correction, you slow the shutter speed by a stop or if you have a half stop option by a combination of half stops. e.g.. a stop more light = 1/60 is slowed by a stop to 1/30.

For those of you with spread sheet minds try this.

Define a named cell, infinityfocuslength For quarter bellows extension in each of the following columns, enter into the first column :-

=(((infinityfocuslength/4)*1)+infinityfocuslength)^2/(infinityfocuslength^2)

Copy that across as many columns as you like ( 11 will give you 3 full extensions ). Having copied, go to column 2 and change *1 to *2, column 3 change *1 to *3 and so on to the end of the row.

In the named cell put in whatever focal length/infinity focus number takes your fancy and press Enter.

Try a different number.

Kinky the shutter factors in the columns do not change !!!

You can add a row to convert these shutter factors to absolute values for f stops by dividing by 2.

And a further row for practical f stop adjustment based on your own opinion.

Regards

Rob

March 2, 2010

Hi Brian,

I wrote this for the other LF forum.

As a new comer to LF, with no light meter, I solved this problem by the following :-

My elderly Linhof monorail has a Graflok back so I can remove the ground glass assembly and use the slide clamps ( to hold roll backs etc ).

I made a cardboard plate from 6mm (1/4 inch) corrugated cardboard. This is 121mm (4 13/16 inches ) by 152 mm ( 6 inches). This fits in the recess that a roll back fits and can be held by the slide clamps.

I marked out the centre of this plate ( by corner to corner diagonals) and scribed a circle.

The circle is the same size as the lens mounting of an old Minolta xg1 I have. Any SLR camera with a self-lighting light meter read out will do the job. In my case I had dead lens so I removed the lens mounting ring, mounted the ring on the SLR body so I have a boss to fit snugly into the into the circle which I cut out carefully using a sharp razor blade.

How to use :-

I set up my shot. Clamp every thing down. Remove the ground glass back. Mount my card. Set the SLR ASA to the film speed ( later you will learn to read your negatives and may well find you get better results by being 1/3 or ½ a speed slower on your ASA setting than the film speed). Turn the SLR on.

Here is the trick bit. Holding the SLR to the card I refocus thro the SLR's view finder. Reason – The distance from the lens to the metering cell in the SLR needs to be allowed for due the mirror and prism, i.e. you will move the back stand towards the lens. Once focused, I have a light meter reading. There is a choice I can read just the time with the lens stopped or if the light levels are low I can open up the lens to the largest opening – read the time in the SLR and adjust the time to match my required stop down i.e. one time segment slower per f stop adjustment ( smaller opening ). Remove SLR, card and replace ground glass assembly and refocus. ( If the travel on rail is marked you can note the point you started from and can go back to that point then refocus)

I now have a wiz bang light meter but still carry my bit of card and old xg1 and will often use it to set a known datum point.

This system will compensate for bellows extension and with the old xg1 I get an all over grey card reading as if I were using an incident meter. It all so reduces the number of numbers – f-stops – times etc you need to think about while you are learning. If you take notes, which I highly recommend, you will very quickly find out which speeds on which shutters are too fast or too slow. I made up small charts for each lens with 1/3 or ½ stop adjustments listed for the various speeds of my elderly shutters( these go in the back of my note book ).

Have fun and enjoy your new past time.

Regards

Rob

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Posts posted by rob_hale1