[Wheatfield]

So, let me get this straight. With bellows, one has to first turn the aperture ring to take a reading, 2nd is to take a reading (with an M lens) by pressing the green button, then third turn the aperture ring back to the first setting, then fourth to push the shutter button to take the pic. My question is, why is there a need for step 3 - why can't one just leave the aperture ring setting from step one remaining on the lens?

I understand the part about having to use the green button in M mode - thanks!

What I do is compose with the lens wide open, then stop it down to the shooting aperture and take a meter reading. Using the green button method, you may be done, take a picture and see.
The metering range of these cameras can be a bit limited, so sometimes the combination of the small lens aperture and the bellows extension can put the meter out of it's range, in which case the chosen shutter speed may not be optimal.

Consequently, sometimes it's compose and focus, stop the lens down, take a meter reading and set the shutter speed (the green button combines this into one user operation), take the picture, chimp, rinse and repeat.

I tend to make fairly heavy use of the histogram when I'm shooting with a bellows as that is what tells me if everything is correct regarding the exposure.

Thanks for your reply. I understand all of it. I also agree that, especially in photography, that simplified (or over simplified) terms/definitions can lead to confusion. Seems like some times, or even often times, a single word or short phrase can have more than one definition/meaning....

Sometimes, when you ask a person what time it is, they will tell you how to build a clock. On the surface it may seem helpful, but in reality it isn't answering the question, and may just overcomplicate things.
There is a fine line between giving not enough information and giving too much information. Too much information can lead to confusion, causing more questions, which can lead to more confusion.

Imagine asking what time it is, being told how to build a clock, asking for some clarification and being told how to build an atomic clock.

This is why I try to keep explanations fairly simple. It's easier to provide clarification on a simple answer than to walk back a complicated one.

The mechanics of photography really isn't all that difficult.

One thing you will want to look into at some point if you are serious about extreme macro photography is focus stacking.
Securing adequate depth of field is very often a problem in macro, especially when using a bellows where magnification ratios are often greater than 1:1 (the object is smaller in real life than it is on the sensor/ film).

The image below is a focus stack shot with the K1, Pentax Auto Bellows and a Fujinon 90mm enlarger lens.. The flowers are under 1 cm across.

[Lowell Goudge]

So, let me get this straight. With bellows, one has to first turn the aperture ring to take a reading, 2nd is to take a reading (with an M lens) by pressing the green button, then third turn the aperture ring back to the first setting, then fourth to push the shutter button to take the pic. My question is, why is there a need for step 3 - why can't one just leave the aperture ring setting from step one remaining on the lens?

I understand the part about having to use the green button in M mode - thanks!....

The other thing you can do, with any bellows or even with old M42 lenses where there is no aperture control, is you can shoot in AV mode.

Focus wide open , then stop the lens down, and the camera will take the shot with an appropriate shutter speed.

[Michael Piziak]

No, what I meant was:

1. close the aperture to take a reading with the green button (in M mode) -> with Av step 1 can be skipped (except for taking a test picture to evaluate the exposure (and maybe adjusting exposure compensation to your liking)
2. open the aperture and focus your subject (likely by moving the camera closer to the subject or further away)
3. close the aperture and take your picture

You can of course focus first and close the aperture afterwards, take a reading and push the shutter button.
That way you only have to close the aperture once. It depends on your subject, when it is a moving insect I prefer setting the exposure before focusing, to not waste much time after focusing.

ok, I understand now - as I put an M lens on my camera, in M mode, and I now see that the camera has an open aperture when one looks through the viewfinder. I did not previously know this.

---------- Post added 07-30-21 at 06:28 PM ----------

What I do is compose with the lens wide open, then stop it down to the shooting aperture and take a meter reading. Using the green button method, you may be done, take a picture and see.
The metering range of these cameras can be a bit limited, so sometimes the combination of the small lens aperture and the bellows extension can put the meter out of it's range, in which case the chosen shutter speed may not be optimal.

Consequently, sometimes it's compose and focus, stop the lens down, take a meter reading and set the shutter speed (the green button combines this into one user operation), take the picture, chimp, rinse and repeat.

I tend to make fairly heavy use of the histogram when I'm shooting with a bellows as that is what tells me if everything is correct regarding the exposure..

Thank you Wheatfield - what you typed clarifies and is easy to understand!

[Michael Piziak]

My next question(s) and/or statement(s)

Aperture, aperture blades, and diaphragm

After googling and visiting several web pages on the difference(s) between aperture and diaphragm, the two words start to get confused and/or even interchangeable....

It's almost embarrassing to ask, but can someone explain the difference(s) between aperture and diaphragm in words, terms, or phrases as if you were trying to teach a baby what the difference(s) are in the most simple understandable way - please.

[Wheatfield]

My next question(s) and/or statement(s)

Aperture, aperture blades, and diaphragm

After googling and visiting several web pages on the difference(s) between aperture and diaphragm, the two words start to get confused and/or even interchangeable....

It's almost embarrassing to ask, but can someone explain the difference(s) between aperture and diaphragm in words, terms, or phrases as if you were trying to teach a baby what the difference(s) are in the most simple understandable way - please.

The diaphragm is the mechanical part of the lens that forms the aperture. The aperture is the opening that the diaphragm creates.
If someone says the aperture has 9 blades, for example, they are using a verbal shortcut. Technically, it’s the diaphragm that has 9 blades.

[Michael Piziak]

The diaphragm is the mechanical part of the lens that forms the aperture. The aperture is the opening that the diaphragm creates.
If someone says the aperture has 9 blades, for example, they are using a verbal shortcut. Technically, it’s the diaphragm that has 9 blades.

Thanks for your explanation. I'm not going to get hung up in my mind, trying to think about which is which or what is mechanical and what isn't. The "verbal shortcut(s)" or them being used interchangeably can be quite philosophical, in my opinion.

[Wheatfield]

Thanks for your explanation. I'm not going to get hung up in my mind, trying to think about which is which or what is mechanical and what isn't. The "verbal shortcut(s)" or them being used interchangeably can be quite philosophical, in my opinion.

Photography is a wonderful place if you want to be an annoying pedant because so many terms are used interchangeably. Sometimes it's just best to accept the obvious meaning of what is being said and move on.

[Lord Lucan]

The aperture is usually expressed as an F number. This was originally the ratio of the focal length of a simple single lens to the diameter of the hole as close to it as possible that lets the light through. Conceptually that is still so, but the physical diameter of the "hole" in a complex modern lens probably nothing like that which the F number would imply. But we still refer to the aperture number as if it were an equivalent simple lens.

The variable diameter physical hole buried well inside a modern lens, is the "diaphragm" and nesds only concern the manufacturers and repair guys. In a zoom lens it might even change in physical size as you zoom while keeping the same F number, or (in cheaper zoom lenses) the F number might change even though the physical size stays the same.

But maybe I'm telling you how to build a clock now

[Michael Piziak]

Thanks everyone for your courteous and understandable answers.... I give everyone a green thumbs up that answers....


Now more statements and questions about:
Extension Tubes, Bellows, and Helicoid(s)


Previously, I created a post in the lens discussion forum here. I only own the extension tubes. I learned things in that post – some things that will transgress to this post.


Most of the time, my Asahi extension tubes perform flawlessly. However, sometimes they misbehave. On occasion, when I press the green button then they won't stop down - I notice this by both what I see in the viewfinder and also a much decreased clicking sound volume. At one time I thought it was one of the tubes acting upor having the 3 connected in a certain way. But after experience and piddling, I have discovered that they only do this after they've gone some time without being used - I believe one of the tubes has an aperture lever that gets "sticky" after not being used over time. Exercising all of them a bit,however, clear up the problem. A quick question: Does it matter what order the 3 tubes are attached together if all 3 are attached together – I think it doesn’t matter.


It’s my understanding that, when it comes to stopping down, only the extension tubes have the ability to do it automatically as only they have the aperture lever arms – obviously hence their name is “Asahi Pentax Auto Extension Tubes.” Therefore, to the extent of stopping down, the helicoid and the bellow act in much the same manner – one manually does the work of stop down metering on either.


After input from users in the other thread, I’ve given it thought and decided to buy the bellows next – to achieve more magnification in my photos. The bellows do come in k mount, right?

As users stated, buying more extension tubes probably places a lot of wear on the camera body, as there are more lever arms for the body to attempt to physically power – with my experience with “sticky” lever arms on the tubes I have, I don’t think it’s wise to add more tubes. Perhaps I would pick up a #1 tube only (the shortest auto extension tube), but no more than that.

Later on I’ll think of buying the helicoid, but I can’t see much advantage of having them other than being able to have intermediate adjustments (with adding a second focusing ring).


A simple questions: Why does he call these bellows a "2" at 0:12 - https://youtu.be/QWGfwqqbSB0?t=12



Please reply/comment on anywhere here as to my thinking is wrong – or even right or you want to elaborate on also…

[Wheatfield]

[SIZE=3]
A simple questions: Why does he call these bellows a "2" at 0:12 - https://youtu.be/QWGfwqqbSB0?t=12

That's what Pentax called them. I expect the M42 bellows was the Auto Bellows 1, or some such.

BTW, hang on to your extension tubes, you will need the shortest one to mount on the back of the bellows to allow for ease of mounting them onto the camera. The prism extension interferes with mounting the bellows, the short extension tube moves them far enough forwards that mounting and dismounting them is possible without disassembling the rear mount from the bellows every time.

[UncleVanya]

Tip: you may find it easier to Mount the bellows using an extension tube first then the bellows to avoid overhang issues with the pentaprism.

[Michael Piziak]

That's what Pentax called them. I expect the M42 bellows was the Auto Bellows 1, or some such.

BTW, hang on to your extension tubes, you will need the shortest one to mount on the back of the bellows to allow for ease of mounting them onto the camera. The prism extension interferes with mounting the bellows, the short extension tube moves them far enough forwards that mounting and dismounting them is possible without disassembling the rear mount from the bellows every time.

Oh, ok, so the "Bellows 1" is likely the M42 Pentax Bellows and the "Bellows 2" is likely the Pentax K Bellows. I understand that you can't be completely confident on this, so I *much* appreciate your proposed explanation !


Also, thanks so much for the tip on the Pentax Bellows 2 !
I assume the difficulty with the Pentax K Bellows is only apparent with the "newer" Pentax digital SLRs and not so on the older Penax SLR film camera bodies.

---------- Post added 07-31-21 at 03:56 PM ----------

Tip: you may find it easier to Mount the bellows using an extension tube first then the bellows to avoid overhang issues with the pentaprism.

Thank you UncleVanya - your reply is consistent with Wheatfield's tip(s).

Regards,

Michael

[Wheatfield]

Oh, ok, so the "Bellows 1" is likely the M42 Pentax Bellows and the "Bellows 2" is likely the Pentax K Bellows. I understand that you can't be completely confident on this, so I *much* appreciate your proposed explanation !


Also, thanks so much for the tip on the Pentax Bellows 2 !
I assume the difficulty with the Pentax K Bellows is only apparent with the "newer" Pentax digital SLRs and not so on the older Penax SLR film camera bodies.

I decided to look. There is a Pentax Auto Bellows in M42 mount.
There is also the Pentax Bellows K.
And the Auto Bellows 2.
Cameras with prism overhangs are a problem. I'm not sure if any of the later film cameras had one of those. I'm pretty sure all the DSLRs have them.

[Michael Piziak]

I decided to look. There is a Pentax Auto Bellows in M42 mount.
There is also the Pentax Bellows K.
And the Auto Bellows 2.
Cameras with prism overhangs are a problem. I'm not sure if any of the later film cameras had one of those. I'm pretty sure all the DSLRs have them.

ok, I took a llook at the Pentax Bellows 2 on the auction site. It's my understanding that the Pentax Bellows 1 and Pentax Bellows 2 are both m42 screw mount - right?

So, I should get the Pentax Bellows K, right?

Addendum: I came across something called the Pentax Auto Bellows M on the auction site that appears to be k mount also - perhaps someone could comment on the difference between these and the Pentax Bellows k. I'm looking to buy one or the other with hopefully the help/input from you folks here

Info: https://www.pentaxforums.com/accessoryreviews/pentax-auto-bellows-k-slide-copier-k.html

and/vs. https://www.pentaxforums.com/accessoryreviews/pentax-auto-bellows-m-slide-copier-m.html

[othar]

ok, I took a llook at the Pentax Bellows 2 on the auction site. It's my understanding that the Pentax Bellows 1 and Pentax Bellows 2 are both m42 screw mount - right?

So, I should get the Pentax Bellows K, right?

Addendum: I came across something called the Pentax Auto Bellows M on the auction site that appears to be k mount also - perhaps someone could comment on the difference between these and the Pentax Bellows k

You can find informations about the different bellows here:
Bellows, Extension Tubes, Etc. (Genuine Pentax) - Pentax Camera Accessory Review Database

Auto bellows M:
PENTAX Auto Bellows M and Slide Copier M reviews - Pentax Camera Accessory Review Database

bellows unit K:
PENTAX Bellows Unit K reviews - Pentax Camera Accessory Review Database

There is also a auto bellows K version: according to the reviews it offers some minor differences to the auto bellows M version, but I wasn't able to pinpoint the exact differences