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05-28-2021, 07:51 AM - 1 Like   #16
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Location: Almere, the Netherlands
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QuoteOriginally posted by barondla Quote

Cool project! Can't wait to see some results. One thing to keep in mind. 110 lenses don't have adjustable apertures. The system is set for F 2.8. The further your adapted lens is from this, the greater the exposure error. Luckily negative film has lots of latitude.

Thanks for sharing,

I have a pair of 2.8 lenses but it is not necessary. The camera measures through the lens, so with a smaller aperture, the camera assumes darker conditions.

Last edited by beeperhorrie; 07-10-2021 at 01:05 PM.
07-18-2021, 02:37 PM - 1 Like   #17
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The project actually failed. The diaphragm is located in the camera body just in front of the mirror and therefore at a very short distance from the film. With a telephoto lens that is too long (from about 400mm) vignetting will occur on the photo. If the diaphragm is not fully open, problems arise with shorter lenses. If the aperture is closed (f18 at 110 Super), there are already problems at 100mm.
The aperture screens the image.

See the schematic image below.

What do the photos look like? Well, that in itself is very good. The photos with the aperture open are usually very beautiful. They also use the best part of the lens, the center.
Pentax 135mm

Unfortunately, most photos suffer from vignetting.
Pentax 135mm

Tamron 200mm

Since the Pentax 110 Auto is a fully automatic camera, you cannot choose the aperture yourself. What I did find is the interpretation of the automatic exposure of both the regular Auto 110 and the Auto 110 Super. These values ​​are shown below in the diagram with the EV values. It is therefore important for the most common Pentax (the Auto 110) to ensure that the camera indicates in the viewfinder that the flash should be used (1/30 sec.). For the Auto 110 Super that is 1/60 sec.

These times immediately make it necessary to work from a tripod with the cable release. Sports promotions are therefore excluded. Because you have to stay below EV8 (or EV9 for the Super), you will have to temper the incoming light on sunny days with filters. Also don't forget to close the viewfinder because the exposure will be affected otherwise.


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