[sky_light]

Hello!This is my first post here.

So far i'm loving all the review and I thank everyone who has contributed to the great content of this forum!


I just recently acquired the DA 35mm F2.4 Prime lens (SMC Pentax-DA 35mm F2.4 AL Reviews - DA Prime Lenses - Pentax Lens Reviews & Lens Database)

My question:

I already own a 52mm CPL filter.
I'm looking for a way to attach both a 52mm filter & and a hood on the lens at the same time.
Since this lens's filter thread is 49mm, i would most probably need to use a step-up filter adapter (49mm -> 52mm).

So far i don't have any experience with such adapters. Could you please recommend a solution based on your experience, which will this allow me to mount a lens hood as well as a filter simultaneously?

Any advice would be very much appreciated.
Thank you!




P.S.
The official lens hoods which are offered for this lens are the following. I don't own any of them, and therefore i'm unable to verify if using either will allow me to mount a 52mm filter up front.

PH-SA49



RH-RC49

[MarkJerling]

Welcome to the forum.

Would it not be easier to simply purchase a filter that matches the lens' filter thread, i.e. 49mm? Put another way, I think you'll find a 49-52mm step-up ring will be very nearly the same cost as another CPL filter and you'll be able to use the lens' original hood.

[sky_light]

Thanks for the reply!

Unfortunately a step-up ring is a fraction of the cost of a new filter. That's why i'm trying to find a solution to use the filter I already own, instead of buying one to use just for a single lens.

Problem is what lens hood will I be able to mount together with the CPL ring, since this filter needs to be able to rotate after all.

[JohnX]

52 mm RC49 style hood/cpl/52-49 step up/lens, BUT, the hood might not be as effective because of its larger overall diameter.

[seventhdr]

Hello!This is my first post here.

So far i'm loving all the review and I thank everyone who has contributed to the great content of this forum!


I just recently acquired the DA 35mm F2.4 Prime lens (SMC Pentax-DA 35mm F2.4 AL Reviews - DA Prime Lenses - Pentax Lens Reviews & Lens Database)

My question:

I already own a 52mm CPL filter.
I'm looking for a way to attach both a 52mm filter & and a hood on the lens at the same time.
Since this lens's filter thread is 49mm, i would most probably need to use a step-up filter adapter (49mm -> 52mm).

So far i don't have any experience with such adapters. Could you please recommend a solution based on your experience, which will this allow me to mount a lens hood as well as a filter simultaneously?

Any advice would be very much appreciated.
Thank you!




P.S.
The official lens hoods which are offered for this lens are the following. I don't own any of them, and therefore i'm unable to verify if using either will allow me to mount a 52mm filter up front.

PH-SA49



RH-RC49

The normal way you would mount these this is lens (49mm) --> Step up ring (49mm to 52mm) --> 52mm CPL filter (52mm) --> Lens Hood (52mm).

Once you have stepped up to a 52mm filter you need a 52mm lens hood. Pentax should still make a PH-SA52mm or a PH-RA52mm (Square or round standard lens hood for 52mm filter diameter), or a 52mm rubber lens hood for a standard lens.

I said use a standard lens hood because your 35mm lens will act as a standard lens when mounted on a camera with an APS-C sized sensor.

Also check that your 52mm CPL filter has filter threads on the front of it on to which you could then attach a lens hood.

Hope this helps.

Regards

Chris

[sky_light]

Thank you! You answered my question regarding setp-up rings & filters & hoods completely!

----

However your reply raised another question. I'd like to verify if my understanding is correct, as what i've read so far differs from the information you have provided:

because your 35mm lens will act as a standard lens when mounted on a camera with an APS-C sized sensor.

According to several online sources, the DA 35mm is a ASP-C format lens.
For example: SMC Pentax-DA 35mm F2.4 AL Reviews - DA Prime Lenses - Pentax Lens Reviews & Lens Database -> "Image Format: APS-C"

Additionally:
"crop sensors dont need cropping with cropped lenses" - Pentax (lens) - Wikipedia

Therefore, shouldn't the viewing angle of this DA lens be unghanged when used with crop-sensor body? I'm not sure what you mean by "act as standard lens".

[UncleVanya]

Ok. Ignore the wiki article for a moment. All 35mm lenses made for any size sensor ever made including 8x10 view cameras will show the same angle of view on a cropped sensor body. The angle of view will be the same, but on lenses made for larger sensors a lot of the image circle available if the sensor was larger will have been cropped away, leaving only the same image size as the cropped lens. If you reversed the situation and mount a cropped lens on a large format camera the tiny portion lighted up by the lens will resemble the image seen on the cropped sensor, surrounded by black where the lens fails to illuminate the larger sensor. The technical reality is that a cropped lens on a cropped sensor isn't cropped because it is made to project only enough of an image circle to cover that size sensor, but this has nothing to do with how wide the angle viewed by the lens appears.

Thus a 35mm lens is going to look like a "normal" lens on a crop sensor. This is true if the lens is made for that sensor or for a larger sensor.

My solution for the problem you face is, step up ring, filter, 52 mm hood (Nikon metal spring mount from the 80's), 52mm cap. The hood is reversible and fits over the lens. I've also done this with a collapsible rubber hood.

---------- Post added 03-24-18 at 08:48 AM ----------

The Crop Factor Unmasked - Articles and Tips | PentaxForums.com

[D1N0]

Focal distance remains the same, whether you use a lens on a cropped or a full frame body. Field of view changes. Simply because the sensor the lens is projecting on from the same distance is smaller. Therefore the practical field of view on aps-c is smaller than on full frame. You are missing the parts that fall beside the sensor (th DA 35mm does cover full frame because it is based on a full frame lens design even though it was marketed as aps-c. Pentax didn't have a full frame camera at the time). This means the field of view of the lens has to be reduced by the crop factor (fov/1.52) compared to full frame. This also means you can use longer hoods on aps-c than on full frame because vignetting will start to show up in the image much later..

Personally I don't think you really need a hood for the DA 35. coatings are good enough to shoot without one.

[pschlute]

Therefore, shouldn't the viewing angle of this DA lens be unghanged when used with crop-sensor body? I'm not sure what you mean by "act as standard lens".

What Chris means is that the field of view on an aps-c camera is narrower than on a FF camera for the same FL lens. Therefore you can use a hood like the "Standard Lens 50mm hood" that was originally designed for a FF 50mm lens. You will not get vignetting and it will help you keep more glare out of your shot.

Irrelevant to you, but you should not try it the other way round ie use a 35mm lens hood that was designed for an aps-c lens on a 35mm FF lens on a FF camera. You may get vignetting or even catch the hood in the frame.

[sky_light]

Regarding lens hoods:

Thanks to everyone for the useful input!

I'll go with a 49-52 mm step up adaptor, and look for a hood (if needed at all) afterwards.

I'm curious what this nikon metal spring-mount lens hood is, that allows the hood to be mounted in reverse on a filter thread?



The angle of view topic:

What Chris means is that the field of view on an aps-c camera is narrower than on a FF camera for the same FL lens. Therefore you can use a hood like the "Standard Lens 50mm hood" that was originally designed for a FF 50mm lens. You will not get vignetting and it will help you keep more glare out of your shot.

Irrelevant to you, but you should not try it the other way round ie use a 35mm lens hood that was designed for an aps-c lens on a 35mm FF lens on a FF camera. You may get vignetting or even catch the hood in the frame.

short and simple explanation, thank you!

What I finally managed to understand is that angle of view is simply different on Full-Frame and Crop-Sensor lens of the same focal length label (for example 35mm).

For example the Pentax FA 35mm F2 AL lens (full frame) has a angle of view of ~63 deg. diagonally,
while the Pentax DA 35mm F2.4 AL lens (ASP-C) has an angle of view of ~44deg. diagonally.

[dave2k]

I use hoods most of the time and they can be a little awkward when using with a CPL. This is because you'll want to rotate the front lens of the CPL to optimize the effect of the CPL. You can reach into the front of the hood with a finger, but it's easy to get fingerprints on the CPL this way. Many of the Pentax lens hoods attach to the lens behind the filter and have a little, removable panel on one side of the hood so you can remove the panel and reach through the panel opening to rotate the CPL. I don't know if there is such a hood in the size you would need for your lens. These hoods are usually lens-specific and the lens has catches to mount the hood. You could also get a collapsible rubber lens hood that fits behind the CPL and rotate the CPL before you extend the rubber hood. This might work best.

[pschlute]

What I finally managed to understand is that angle of view is simply different on Full-Frame and Crop-Sensor lens of the same focal length label (for example 35mm).

For example the Pentax FA 35mm F2 AL lens (full frame) has a angle of view of ~63 deg. diagonally,
while the Pentax DA 35mm F2.4 AL lens (ASP-C) has an angle of view of ~44deg. diagonally.

Not quite. The angle of view of those two lenses is almost identical. ie when measured on an aps-c sensor the DA is 44 degrees and the FA is 45 degrees. It is not the lens itself that causes the change in angle of view but the sensor size. Because the aps-c sensor is physically smaller than FF it takes a smaller bite out of the image circle that a lens projects. This is what narrows the angle or field of view.

The differences between a "made for aps-c sensor" lens and a FF lens, can be that the former projects a smaller image circle and therefore won't cover the FF sensor size. The DA 10-17 Fisheye is an example of this. On the other hand both the the DA* 200mm f2.8 and the DA* 300mm f4 cover the FF sensor and so behave exactly like a FA 200 or FA300 lens would behave on a FF camera.

Newer DA lenses tend to have better flare resistance due to better coatings but the optical properties as far as magnification is concerned is identical.

[suraswami]

amazon.com : BestDealUSA FOTGA 49mm Screw Mount Standard Metal Lens Hood for Canon Nikon Pentax Sony : Camera Lens Hoods : Camera & Photo?tag=pentaxforums-20&

This is what I use on my F35-70 and DA 50 F1.8 (bought 49mm and 52mm version, going to buy one more, 58mm version for my F35-135).

Only problem with this hood is you need to use one size bigger lens cap. 52mm lens cap will fit the 49mm lens hood. If you use a 49mm lens cap on the 49mm hood, the cap kind of goes in and gets semi stuck.

Hope this helps.

[sky_light]

Your input is much appreciated. Thanks!

A circular lens hood to be mounted on top of the CPL makes perfect sense. I'd go with that setup!

From all the explanations above, I see that a "flowercup" type lens-hood is probably not needed.

This topic has been fully answered for me. If the forum management can close the topic if they like.

[UncleVanya]

Your input is much appreciated. Thanks!

A circular lens hood to be mounted on top of the CPL makes perfect sense. I'd go with that setup!

From all the explanations above, I see that a "flowercup" type lens-hood is probably not needed.

This topic has been fully answered for me. If the forum management can close the topic if they like.

Threads are only closed when there is a problem.

You got the right idea - hood after filter if circular - just rotate the hood and filter at the same time.

The nikon hood has a metal threaded band that is split and made of spring steel. The slider or buttons on the side of the hood allow you to squeeze it smaller and insert it and then release and have it grab the threads. The band is tall enough that it works both mounted forward or backward. An example is the HS-8 hood for an 85mm f/2.