How to decide which enlarging lens to use

[abhishek@1985]

Hi friends,
I am a total newbie and if my question is very stupid please forgive me.
I have just started out with darkroom printing and I must say, its addictive.. addiction is worse than even my cig smoking

However, I am still trying to figure out which enlarging lens to use and how to decide among them.

I generally tried in the past with 80mm enlarging lens for a medium format negative. But while trying to print a picture this week, I found that the picture appears so blurry, out of focus upon the easel. I have tried to move teh enlarger upto and down and even fine tune focus using the focussing knoob but the picture was never in focus. Then i switched the lens to 135 mm and I was able to focus and print.

Wanna know from you guys how do you decide when to use which mm enlarging lens?

 

[fretlessdavis]

Sounds like you can't compress the bellows enough to focus with the 80mm. What enlarger are you using? It may take a recessed lens board to get the 80mm to work, standard lens board if it's extended, or like my LPL, you can flip flop the lens board for short and long lenses.

Maybe it would help us more to know what enlarger, lenses, and film format you're using?

 

[abhishek@1985]

The enlarger used was a Bessler MXT, lens - Nikkpr 80mm f5.6 and format was 6x6..
Wanna know how you decide which enlarger lens to use when...

 

[mgb74]

The MXT should allow you to use an 80mm lens. I'm not an expert, but in looking for Beseler lensboards a while back, I don't recall seeing a recessed board (other than the one with a very slight recessed specifically for Nikon enlarging lenses).

Have you, or someone you trust, used your 80mm lens successfully in any enlarger? It's possible the lens is defective.

 

[snapguy]

lens

Normally, you should be able to use an enlarging lens about the same length as the "normal" lens on the camera -- 50mm for full frame 35mm, 80mm for 120-size film, and so on. I suspect your enlarger has a control lever or knob on the side in the area where the bellows are. This needs to be set to the size of the lens/film size you are using. Your enlarger may have two sets of bellows and the lever may control the top set of bellows. When this knob or lever is not set right you may not get full illumination over the whole area of the negative.

 

[Rick A]

I used to have an MX, you should be okay with the 80mm lens on a flat lens board. What size enlargment are you attempting, maybe you are going too small. IIRc, I had problems getting smaller than 5x7 and had to use my 150mm to get down to 3.5x5. It's been too long snce I owned it to remember if the condensors adjust like the 23c.

 

[JLP]

I mostly print with a 45MXT and have no problems with an 80mm. For 35mm I use a Nikon 75mm and for medium format 100mm. If I recall correctly I have used a 50mm in the past.

 

[ic-racer]

Wanna know from you guys how do you decide when to use which mm enlarging lens?

Measure the diagonal of your negative and use the enlarging lens closest to that measurement.

 

[fotch]

I like to use the largest focal length that will enlarge the negative to the size print I want. For medium format, my choice of lens, most of the time is a 100 or 105mm lens. If making a smaller print, might use a 135mm.

 

[eddie]

Your enlarger may have two sets of bellows and the lever may control the top set of bellows.

I think this is the reason for the problem. There are 2 sets of bellows. The top one's extension is based on the film size. The bottom one is for focusing. If I recall correctly (I sold mine awhile back...), the top bellows should be fully extended for 4x5, compacted for 35mm. I'm assuming you're using the condensers, not cold light. There should be a piece of metal attached to the right side of the head, with markings for the different film formats.
The part you need to adjust is the Negative Stage Guide- No.13, in this pdf: http://backglass.org/duncan/darkroom/beseler_45mxt.pdf

 

[MattKing]

Check that the upper bellows isn't moving when you replace the negative carrier or focus. There should be a lock for it.

 

[Ian C]

According to page 3 of the Beseler 45MXT manual, an 80mm lens using the 39mm Leica thread requires the flat 8023 lens board. Table 1 on that page shows an 80mm lens and a 6 x 6cm negative should be useable from 2.6X to 11X.

http://www.bhphotovideo.com/c/product/4517-REG/Beseler_8023_39mm_Flat_Lensboard.html

If the 80mm lens doesn’t focus, but a 135mm lens does, then the 80mm lens is likely too far from the negative. Examine the enlarger to determine why you can’t place the lens at the proper position with the focusing knob.

Beseler also makes the 8022 5/8” recessed mount with 39mm clearance hole that places the lens 5/8” (15.9mm) closer to the negative than the flat board at the same bellows position. This might solve your problem, but shouldn’t be needed according to the 45MXT manual.

http://www.bhphotovideo.com/c/product/4533-REG/Beseler_8022_39mm_Lensboard_with_5_8.html

The adjustment of the upper bellows is necessary for proper light distribution depending on the format and whether the condenser unit is installed, or if the dichroic lamp house and diffusion unit are installed. This is irrelevant insofar as focusing the lens is concerned. Focus is determined strictly by the lens-to-negative distance and no other factor.

http://backglass.org/duncan/darkroom/beseler_45mxt.pdf

 

[MattKing]

Ian is correct, but if the adjustment control for the upper bellows is slipping, then the negative stage is moving as well, which can lead to problems with focusing.

 

[abhishek@1985]

Thanks everyone for your thoughts and answers.
Definitely I shall check for upper bellows in teh enlarger.
However, wanna know what difference it would make if I use 80 mm or 100 mm or 135 mm lens in enlarging when teh final print size is teh same - say at 6 inx6 in on 8X10 RC paper.

 

[Rick A]

Thanks everyone for your thoughts and answers.
Definitely I shall check for upper bellows in teh enlarger.
However, wanna know what difference it would make if I use 80 mm or 100 mm or 135 mm lens in enlarging when teh final print size is teh same - say at 6 inx6 in on 8X10 RC paper.

Theoretically, only distance between head and easel. The longer the focal length, the farther the head distance, which makes it easier (for me anyhow)to focus and use easel.

 

[Thomas Bertilsson]

Abhishek,

I mostly use an 80mm Minolta Rokkor lens to enlarge 6x6 negatives. Although I often make enlargements from my girlfriend's 6x9 negatives, in which case I must use a 100mm lens, and when I switch to 6x6 I often don't change back to the 80mm, mostly because I'm lazy.

I usually print 8x8" on 11x14 paper from 6x6, but sometimes I make little 6x6 prints on 8x10 paper too, and then it's nice to have a longer focal length, to create some distance between the paper and the lens. I have even used a 150mm lens for that, and it works really well.

When you change the focal length of the enlarger lens, you also change what the distance between the negative and the lens must be. If the enlarger has a bellow, this must be adjusted in addition to focusing. This is probably what happened to you in the darkroom, that you switched the lens (or somebody else did), without adjusting the enlarger for the different lens.

 

[Rick A]

I use a 135mm when I print my 6x6 negs to small sizes, mainly to keep from smacking my forhead on the enlarger. It gives me room to work under the head. I need the extra room for my focus scope and to lift the arms on my easel to slide paper in. The enlarging times are the same as if I used an 80mm, so it's only for my convenience.

 

[abhishek@1985]

Thanks guys.. As far I have understood, I should chnage the distance between the enlarger lens and the negative while chnaging the lens from 135 to 80.
However, I actually realized Rick's point that when I used teh 135mm , I had lot of room for teh same enlargement which made my life easier to focus as my head was not hitting to teh enlarger.

I shall try chnaging the distance between the lens and the negative and see how it goes.

 

[mklw1954]

80mm is the proper lens focal length for 6x6 negatives.

On my Besler 23CII enlarger, for 135 (35mm) negatives (a 50mm lens is used), the upper bellows is set to be the most extended, i.e., the lamp is furthest from the negative. For 6x4.5 and 6x6 negatives (a 75mm or 80mm lens is used), the upper bellows is less extended, i.e., the lamp is closer to the negative. For 6x7 (90mm lens is used) the lamp is even closer to the negative. And for 6x9 (110mm lens is used), the lamp is closest to the negative. There are markings indicating the proper setting of the upper bellows depending on the negative size. The closer the lamp to the negative, the more potential for the negative to buckle due to the heat, with heat absorbing glass used to eliminate that effect.

The distance between the negative and the lens (the lower bellows) is then simply adjusted to achieve focus. A grain focuser is good for final fine focusing.