80mm vs 50mm for big 35mm prints

RJS said:

You MUST align your enlarger accurately. Use one of the optical tools (Versalign, Zigalign) for this. Obtain a top quality 50mm enlarging lens - a list is available in Ctein's book (Componon S, Nikkor N, Apo Rodagon are some). Do not stop down more than 2 to 2 1/2 stops. More gives a less sharp image. You will have plenty of coverage from one of these lenses and they are all corrected for greater enlarging ratios than nearly all the longer lenses - the manufacturers are aware that 35mm gets 'blown up' more than 6X6. Spend a few dollars and get Ctein's book; people posting here sometimes offer misinformation. Ctein is an MIT graduate with many years of experience and has conducted extensive testing of enlarging lenses. You neglect this source at your own peril!

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I agree that things must be done properly. But what if they have been as far as you can tell and things still don't work out? sometimes there is a gremlin in the system somewhere and it takes some head scratching to find it....

As stated earlier get a Rodagon-G lens. In my oppinion the best lens for large prints. I work in a Darkroom where I often make prints 140x210 cm, and I always use the Rodagon-G Lens. The problem is that the enlarger gets so hot that the negativ gets warm and expands leading to " Wanderkorn", that is the grain moves as it gets warmer. So I warm up the enlarger for about 5-7 minutes before exposure. Another thing is to prevend really long times (30 min. or so) I only close the stop by one stop. The prints are sharp even in the corners. Sometimes I believe the prints are sharper at really large enlargements if you only stop down one stop. You know this feeling I have..., sometimes.

I just bought a parallel alignment laser thingy and it is great. I discovered a few useful things, but essentially my enlarger was very, very close to spot on. I am now convinced that field curvature is having an impact, esp at the wider apertures I was using. I am in the running to get a Schneider 45 HM or 50 APO rodagon and see if I get better extreme corners. I'll look up the Rodagon G. If I recall thats the extremely rare type for ENORMOUS ratios... like 210cm prints! WOW... And I was getting frustrate with 40x50!

Reading through this thread a couple of things come to mind: most of them are too small for max quality due to budget restaints and family issues.
When designing a new darkroom from scrap it needs to be high and lots of room around the enlarger.
The enlarger should have a motorized focusing if posible, a wife that loves the darkroom as much as you do is an absolute pré.
Don't be shy to use lenses that are by general consensus too long for the negatives that you use them for, experiment to perfection and have at least a couple of vacum boards of diferent sizes around, just to mention a few things........
Oh jeh, and some money for the best optic's available.

At the end you come up with a darkroom that is 3 meters high, with an enlarger that uses just one or two long lens for all formats.

I am in the designing process right now: it will be too small and not high enough: it will have to fit into my appartment......
But dreaming about a top-notch darkroom can be fun.........

Peter

I have largely fixed the issues encountered and here is what I did:

Used a laser alignment tool to get everything as perfect as possible. I discovered that bellos compression with shorter lenses (even with recessed boards) on the 10x8 enlarger causes a slight deviation from true zero which can be adjusted for. This only affects the lens stage and is a 1 minute adjustment fix with the laser tool I therefore set up for 120 and then re-do things if I am doing very big 35mm prints. For smaller prints it makes no difference.

I found the easel was partly the culprit. I main use a 2 blade photon beard and while the blades hold the paper dead flat, the frame is not perfeclty against the board/paper. This causes the paper to rise up slightly on the top left hand corner and to a lesser extent along the whole left edge, being more pronounced n the top left corner (because in the bottom left the blad pins the paper flat. No issue with small prints, but it does seem to matter when doing 18" prints if the paper is not naturally flat. This explains why I could not understand how I got such perfect corner to corner sharpness on some 19" 35mm prints yet could not repeat that with other prints at 17" off Ilford papers, or Efke. The it dawned on me; the Kentmere lies 100% dead flat and the ilford has a curve. Putting a sheet of each ino the easel and tapping around the edges revealed the kentmere remained flat no matter, but the Ilford rose up a couple of mm due to the easel issue explained. I resolved this by gluing some strips inside the frame of the easel that ensure the paper is pinned completely flat i.e. pressure all round every edgeof the paper.

Laser alignment. I now confirm everything is spot on from easel to neg to lens for important prints. It takes a few minutes only, but it does allow me to shim the easel to get it absolutely perfect and then check the lens is still perfect to the easel. The result has been consistently better corners, which combined with now flatter paper can be seen in the corners, esp the top left.

Stopping down. I have found that stopping down from f5.6 to f8 on my lens does improve corners a touch. When the neg density allows it, I do so.

So as with air crashes, there were a few factors at play:

1. Close but not absolutely perfect alignment (and no a spirit level is not always good enough when dealing with very largen prints off small negs)
2. Two blade easels might not keep the paper perfectly flat if the frame (which does not bend and hang flush as the blades do) is not making perfect contact.
3. Curvature of field is present at wider apertures and stopping down helps with this too.

So there you go. I got there in the end and I hope this is food for thought for anyone battling the same enemy!

PS Kentmere Fineprint is a truly superb paper. I hope when it is reforumlated by ilford it is just as fast as for dense 35mm negs being turned into big prints, it is a godsend.

I would not know the answer because I use short lens for larger enlargement and long lens for small enlargement just to keep the distance reasonable.

Enlarger alignment

Tom,
glad your set up is working.
I have looked at laser levels, the artificial horizon type seems usless for our purpose. The straight single beam is probably the one to use.

Can you please give me/us some guidance on how you did it?

Regards
Danny

Tom Stanworth said:

I have largely fixed the issues encountered and here is what I did:

Used a laser alignment tool to get everything as perfect as possible. I discovered that bellos compression with shorter lenses (even with recessed boards) on the 10x8 enlarger causes a slight deviation from true zero which can be adjusted for. This only affects the lens stage and is a 1 minute adjustment fix with the laser tool I therefore set up for 120 and then re-do things if I am doing very big 35mm prints. For smaller prints it makes no difference.

I found the easel was partly the culprit. I main use a 2 blade photon beard and while the blades hold the paper dead flat, the frame is not perfeclty against the board/paper. This causes the paper to rise up slightly on the top left hand corner and to a lesser extent along the whole left edge, being more pronounced n the top left corner (because in the bottom left the blad pins the paper flat. No issue with small prints, but it does seem to matter when doing 18" prints if the paper is not naturally flat. This explains why I could not understand how I got such perfect corner to corner sharpness on some 19" 35mm prints yet could not repeat that with other prints at 17" off Ilford papers, or Efke. The it dawned on me; the Kentmere lies 100% dead flat and the ilford has a curve. Putting a sheet of each ino the easel and tapping around the edges revealed the kentmere remained flat no matter, but the Ilford rose up a couple of mm due to the easel issue explained. I resolved this by gluing some strips inside the frame of the easel that ensure the paper is pinned completely flat i.e. pressure all round every edgeof the paper.

Laser alignment. I now confirm everything is spot on from easel to neg to lens for important prints. It takes a few minutes only, but it does allow me to shim the easel to get it absolutely perfect and then check the lens is still perfect to the easel. The result has been consistently better corners, which combined with now flatter paper can be seen in the corners, esp the top left.

Stopping down. I have found that stopping down from f5.6 to f8 on my lens does improve corners a touch. When the neg density allows it, I do so.

So as with air crashes, there were a few factors at play:

1. Close but not absolutely perfect alignment (and no a spirit level is not always good enough when dealing with very largen prints off small negs)
2. Two blade easels might not keep the paper perfectly flat if the frame (which does not bend and hang flush as the blades do) is not making perfect contact.
3. Curvature of field is present at wider apertures and stopping down helps with this too.

So there you go. I got there in the end and I hope this is food for thought for anyone battling the same enemy!

PS Kentmere Fineprint is a truly superb paper. I hope when it is reforumlated by ilford it is just as fast as for dense 35mm negs being turned into big prints, it is a godsend.

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Danny,

Just to add to the mix yet another issue and that is of carrier placement. It seems that the Devere 5105 does not place a 35mm neg directly under the lens and so I set up a guide to show where to align the neg on the double glass carrier to ensure it is smack in the centre of the lens.

On to alignment tools: I used the Parallel Alignment tool from Versalab bought from B&H. Its a box about four by three inches with a laser set vertically inside with a bullseye on top from which the laser shines. Set up the first time took a little while as I went back to basics setting the enlarger frame as perfect as I could. Thats not as easy as it sounds because not everything is perfectly flat/square or even machined. Some parts are screwed onto others etc and so there is plenty of scope for false readings if you like. After this, it went along these lines:

Level the baseboard as perfectly as you can with a spirit level. Thats not hard because it is huge and flat.
Remove lens and shine laser up from baseboard to glass carrier (or use supplied glass reflector).
Align head/neg stage to baseboard.
Replace lens at lens stage and place reflector on lens front using supoplied rubber bands.
Shine laser at lens reflector and align lens stage.
Place easel on baseboard and align easel to lens stage. When checked against neg stage it should agree perfectly.
Now all stages should be right at the present position of the head and lens stage, but you will see that as you rack up and down things do deviate a touch. This wont be remotely visible on a small print or even a large one from a 5x4 neg, but for a very large 35mm print it does start to matter.

When making a large print I then go back and do the following (after setting up the neg and getting things roughly focused). This means any adjustments will be perfect for the print itself:

Easel to Neg stage (adjusting easel to the neg stage)
Easel to Lens stage (adjusting lens stage)

On my Devere the above takes all of two mins, which is nothing for a neg I might work on for a day and I can see the difference in the prints, but, when all is said and done, I am trying to stop down to f8 for the larger prints as this helps with perfect corners too. I think in realisty a 10x8 enlarger is not the best route for 35mm large prints. For 14x11 etc none of the above seems terribly neccessary, but as you go to 20x16 and the aperture opens up due to reduced to keep print times sensible, there is a compound effect for sure and there can be dramatic reductions in corner sharpness at wider apertures if things are not perfect. I still think that lens curvature is at play and intend to find a 63mm Nikkor for a little more image circle for those large prints compared to 50mm. Column height is not an issue with my set up. I can get about six feet between lens and paper if i want. however, when selling up and starting again, which I will do soon as I am changing countries, I will get a 6x7/9 enlarger for 35mm and 120 and use something larger for only LF.

Problem Solved - Lge Prints off 35mm and perfect corners

The problem is now 100% fixed. I do not know the root cause exactly i.e. whether it was field curvature with the lenses or some sort of vignetting, but I recently acquired two new (used lenses): a 60mm F4 rodagon and a Nikkor 63mm 2,8 (I bid on both and happened to win both on ebay). With both lenses, at f5.6, I am getting perfect corners and razor sharp grain throughout. I have not tried f4 yet. I have a feeling the original issue was something to do with the enlarger, bellows or something once over about 17".

I have recently printed a whole bunch of images at up to 20" and they are all pin sharp from corner to corner with either lens. Now I don't need to jack the head up to the roof like I did with the 105mm but I still get the performance I want at wider apertures. Alignment is seriously important and I am continually rechaking, but it has been worth the effort.

As an aside, I have just tried the new (old) Adox MCC and found it about a stop and a half faster than MGWT which has made some large prints much easier. The MGWT will print with higher contrast at the extreme end, but the re-done Agfa MCC is very nice on that white base and the speed is seriously handy. I think I prefer the MGWT ever so slightly, but the MCC is much more user friendly and also seems to benefit from very little dry down, whereas the MGWT dries down heavily.

you wont find it easy using f11/16 when making a 20x16 from a properly exposed 35mm neg unless you have some insanely powerful head.

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You can say that again. I have a D2 with 200W bulb and 4x5 condensors. Last time I made a 11x14 print from a 35mm negative, I had to use my 50mm lens because I don't have a proper D2 lens cone. In order to get sharpness, I had print at f/16 or f/22 which resulted in 5-min exposure times. Luckily there was minimal burning to do, so I ducked out of the darkroom and read a book while it was exposing.

Hi,

Are you using a glass carrier? You should not need to stop down nearly that far for a 11x14 (with a glass carrier). This is one of the joys of glass! I can print an 11x14 and get pin sharp corners at f4 so I can only assume your negs are bowing and you are stopping down to compensate with DOF?

BetterSense said:

You can say that again. I have a D2 with 200W bulb and 4x5 condensors. Last time I made a 11x14 print from a 35mm negative, I had to use my 50mm lens because I don't have a proper D2 lens cone. In order to get sharpness, I had print at f/16 or f/22 which resulted in 5-min exposure times. Luckily there was minimal burning to do, so I ducked out of the darkroom and read a book while it was exposing.

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I don't have a glass-type negative carrier for my omega enlarger, plus the grain was very visible in this case since it was a heavy crop out of a 35mm frame, so I didn't want to betray any unsharpness.

Just this last week I finally got the parts I need to project some 35mm negatives from my 8x10 enlarger. Kind of stimulated by both this thread and the other recent thread on the APO Componon 45mm High Magnification lens I did a side-by-side comparison.

The 8x10 enlarger has enough column height to get a big image from an 80mm lens. So I compared an old Schneider Componon (non-S) 80mm lens to a new Schneider 45mm APO Componon HM. I used a grainy 35mm negative and a glass carrier. I compared 4 edge grain and center gain between the two prints. As I was thinking, by just using the center of the image circle on the cheaper lens, the results were similar if not totally identical.