low contrast

[deborah_betz]

I am new to large format, I have a orbit 4x5 with a Calter II-E 1:6,8

f210mm lens..I did a few test shots with agfapan 100. it was taken in natural light, half shadow, medium close up of people. It was a very muddy contrast, which is surprising because agfapan is usually pretty snappy.( i shoot alot of agfapan 35mm). What I am i doing wrong? wrong bellows extention? I am going to be doing a series of city landscapes with this camera, any suggestions would be appreciated

[chad_jarvis1]

Sounds like at a very minimum a case of underdevelopment, though it

could be a combination of underexposure and underdevelopment,

depending on whether the negative is thin or not. Is it?

[chris_jordan3]

might be a camera problem-- a hole in your bellows that is leaking

light, possibly?

[ed b.]

Give us developer, time, temperature, agitation method, and exposure

index, and someone might be able to suggest something.

[michael_kadillak3]

I agree with the previous post as per the subject of light leaks.

Test your bellows with a point light source from the inside in a

darkroom. In you have pin holes, they will be very obvious. I would

also add to make sure that your films holders are in good shape and

are inserted fully. Pulling the dark slide should be done carefully

so as to not pull the holder away from the film backafter in the

process. Insert the dark slide squarely to prevent light from leaking

past the darkslide flap. If you are light tight and it is not a

holder or slide problem, I would look at outdated film or exhausted

developer next. Continue to isolate and eliminate a variable at a

time or your frustrations will cause you to blame the format and that

would be a real shame. Hang in there! Your efforts will be rewarded

when you see the results.

[wilhelm]

Check your bellows and lens board. I did a whole tour of the South

last year, and found out when I got home that my Technika bellows was

splitting and pin pointing, although it had be replaced only a few

years ago and was little used. Also, light can leak around the lens

board if it's not well sealed.

[deborah_betz]

I want to thank everyone for the responses. It is all very helpful.

The negative is pretty thin. i had it processed and proofed at a

commerical lab . I think I am not getting the concept of the bellows

extention and how to adjust the f stop. I am trying to get up to

speed as quickly as possible. I am leaving for overseas tommorow and

at the last minute decided to take this 4x5 camera, in addtion to my

35mm. I have an unusually opportunity to shoot at an unusually time.

[michael_feldman1]

If your negatives are underexposed, I would look elsewhere than

bellows extension. You don't ordinarily need any bellows exposure

adjustment unless you are shooting at very close focus distances.

Having your film developed at a lab is probably the biggest variable

that you will have to deal with in terms of getting the right

contrast (via development time). If you are not sure whether your

negatives are underexposed or underdeveloped, I would try to get

someone knowledgeable to look at them.

[henry_friedman]

I personally would not risk an unusual photographic opportunity to

unfamiliar equipment. Especially when you've already experienced

problems. The advice you'll get on this forum is suberb, but will

take time to digest.

[scott walton]

It sounds as if you need to add more time to your developing. Start

with 15% added time. This will develop your highlights more giving you

a punchier negative.

[bong]

I built a small Excel spreadsheet to calculate bellows

compensation. It displays the compensation factor, compensation in

stops, and the extension at which the compensation should be

applied. I set the compensation increments in 1/3 stops. I can send

you the spreadsheet if you wish.

 

<p>

However, because spreadsheets are such an easy way to spread viruses,

you can build the spreadsheet yourself (with apologies for my

marginal HTML skills):

 

<table cellpadding="3" border="1">

<tr>

<th>

<th>A

<th>B

<th>C

<th>D

</tr>

<tr>

<td>1

<td>135

<td> 

<td> 

<td> 

</tr>

<tr>

<td>2

<td>135

<td>=A2/25.4

<td>=10^(D2/LOG(2))

<td>0.0

</tr>

</table>

 

Now, copy the second row and initialize cell D3, D4, and so on to 1/3

stop values. For example, 0, 0.3, 0.6, 1.0, 1.3, 1.6, etc. For a

135mm lens, for example, this is the table I get:

 

<table cellpadding="3" border="1">

<tr>

<th>

<th>A

<th>B

<th>C

<th>D

</tr>

<tr>

<td>1

<td>135

<td> 

<td> 

<td> 

</tr>

<tr>

<td>2

<td>135

<td>5 3/8

<td>1.0

<td>0.0

</tr>

<tr>

<td>3

<td>150

<td>5 7/8

<td>1.2

<td>0.3

</tr>

<tr>

<td>4

<td>166

<td>6 4/8

<td>1.5

<td>0.6

</tr>

<tr>

<td>5

<td>191

<td>7 4/8

<td>2.0

<td>1.0

</tr>

<tr>

<td colspan=5>And so on...

</tr>

</table>

[bong]

Oops, I forgot the formula that's supposed to go in column A starting

at row 2: =SQRT(C2*$A$1^2) where $A$1 is the focal length of your

lens.

[andre_noble4]

What's that formula for? Have Mercy. Another MIT grad trying to

impress the ladies?